Use Java 14 switch expressions (#82178)

JEP 361[https://openjdk.java.net/jeps/361] added support for switch expressions
which can be much more terse and less error-prone than switch statements.

Another useful feature of switch expressions is exhaustiveness: we can make
sure that an enum switch expression covers all the cases at compile time.

benchmarks/src/main/java/org/elasticsearch/benchmark/indices/common/RoundingBenchmark.java

@@ -89,16 +89,11 @@ public class RoundingBenchmark {
             roundingBuilder = Rounding.builder(TimeValue.parseTimeValue(interval, "interval"));
         }
         Rounding rounding = roundingBuilder.timeZone(ZoneId.of(zone)).build();
-        switch (rounder) {
+        rounderBuilder = switch (rounder) {
-            case "java time":
+            case "java time" -> rounding::prepareJavaTime;
-                rounderBuilder = rounding::prepareJavaTime;
+            case "es" -> () -> rounding.prepare(min, max);
-                break;
+            default -> throw new IllegalArgumentException("Expected rounder to be [java time] or [es]");
-            case "es":
+        };
-                rounderBuilder = () -> rounding.prepare(min, max);
-                break;
-            default:
-                throw new IllegalArgumentException("Expectd rounder to be [java time] or [es]");
-        }
     }
 
     @Benchmark

benchmarks/src/main/java/org/elasticsearch/benchmark/script/ScriptScoreBenchmark.java

@@ -101,28 +101,19 @@ public class ScriptScoreBenchmark {
 
     @Setup
     public void setupScript() {
-        switch (script) {
+        factory = switch (script) {
-            case "expression":
+            case "expression" -> scriptModule.engines.get("expression").compile("test", "doc['n'].value", ScoreScript.CONTEXT, Map.of());
-                factory = scriptModule.engines.get("expression").compile("test", "doc['n'].value", ScoreScript.CONTEXT, Map.of());
+            case "metal" -> bareMetalScript();
-                break;
+            case "painless_cast" -> scriptModule.engines.get("painless")
-            case "metal":
-                factory = bareMetalScript();
-                break;
-            case "painless_cast":
-                factory = scriptModule.engines.get("painless")
                 .compile(
                     "test",
                     "((org.elasticsearch.index.fielddata.ScriptDocValues.Longs)doc['n']).value",
                     ScoreScript.CONTEXT,
                     Map.of()
                 );
-                break;
+            case "painless_def" -> scriptModule.engines.get("painless").compile("test", "doc['n'].value", ScoreScript.CONTEXT, Map.of());
-            case "painless_def":
+            default -> throw new IllegalArgumentException("Don't know how to implement script [" + script + "]");
-                factory = scriptModule.engines.get("painless").compile("test", "doc['n'].value", ScoreScript.CONTEXT, Map.of());
+        };
-                break;
-            default:
-                throw new IllegalArgumentException("Don't know how to implement script [" + script + "]");
-        }
     }
 
     @Setup

benchmarks/src/main/java/org/elasticsearch/benchmark/search/aggregations/AggConstructionContentionBenchmark.java

@@ -107,20 +107,12 @@ public class AggConstructionContentionBenchmark {
 
     @Setup
     public void setup() {
-        switch (breaker) {
+        breakerService = switch (breaker) {
-            case "real":
+            case "real", "preallocate" -> new HierarchyCircuitBreakerService(Settings.EMPTY, List.of(), clusterSettings);
-                breakerService = new HierarchyCircuitBreakerService(Settings.EMPTY, List.of(), clusterSettings);
+            case "noop" -> new NoneCircuitBreakerService();
-                break;
+            default -> throw new UnsupportedOperationException();
-            case "preallocate":
+        };
-                preallocateBreaker = true;
+        preallocateBreaker = breaker.equals("preallocate");
-                breakerService = new HierarchyCircuitBreakerService(Settings.EMPTY, List.of(), clusterSettings);
-                break;
-            case "noop":
-                breakerService = new NoneCircuitBreakerService();
-                break;
-            default:
-                throw new UnsupportedOperationException();
-        }
         bigArrays = new BigArrays(recycler, breakerService, "request");
     }
 

benchmarks/src/main/java/org/elasticsearch/benchmark/search/fetch/subphase/FetchSourcePhaseBenchmark.java

@@ -52,22 +52,13 @@ public class FetchSourcePhaseBenchmark {
 
     @Setup
     public void setup() throws IOException {
-        switch (source) {
+        sourceBytes = switch (source) {
-            case "tiny":
+            case "tiny" -> new BytesArray("{\"message\": \"short\"}");
-                sourceBytes = new BytesArray("{\"message\": \"short\"}");
+            case "short" -> read300BytesExample();
-                break;
+            case "one_4k_field" -> buildBigExample("huge".repeat(1024));
-            case "short":
+            case "one_4m_field" -> buildBigExample("huge".repeat(1024 * 1024));
-                sourceBytes = read300BytesExample();
+            default -> throw new IllegalArgumentException("Unknown source [" + source + "]");
-                break;
+        };
-            case "one_4k_field":
-                sourceBytes = buildBigExample("huge".repeat(1024));
-                break;
-            case "one_4m_field":
-                sourceBytes = buildBigExample("huge".repeat(1024 * 1024));
-                break;
-            default:
-                throw new IllegalArgumentException("Unknown source [" + source + "]");
-        }
         fetchContext = new FetchSourceContext(
             true,
             Strings.splitStringByCommaToArray(includes),

benchmarks/src/main/java/org/elasticsearch/benchmark/xcontent/FilterContentBenchmark.java

@@ -64,20 +64,12 @@ public class FilterContentBenchmark {
 
     @Setup
     public void setup() throws IOException {
-        String sourceFile;
+        String sourceFile = switch (type) {
-        switch (type) {
+            case "cluster_stats" -> "monitor_cluster_stats.json";
-            case "cluster_stats":
+            case "index_stats" -> "monitor_index_stats.json";
-                sourceFile = "monitor_cluster_stats.json";
+            case "node_stats" -> "monitor_node_stats.json";
-                break;
+            default -> throw new IllegalArgumentException("Unknown type [" + type + "]");
-            case "index_stats":
+        };
-                sourceFile = "monitor_index_stats.json";
-                break;
-            case "node_stats":
-                sourceFile = "monitor_node_stats.json";
-                break;
-            default:
-                throw new IllegalArgumentException("Unknown type [" + type + "]");
-        }
         source = readSource(sourceFile);
         filters = buildFilters();
         parserConfig = buildParseConfig();
@@ -87,17 +79,12 @@ public class FilterContentBenchmark {
         Map<String, Object> flattenMap = Maps.flatten(XContentHelper.convertToMap(source, true, XContentType.JSON).v2(), false, true);
         Set<String> keys = flattenMap.keySet();
         AtomicInteger count = new AtomicInteger();
-        switch (fieldCount) {
+        return switch (fieldCount) {
-            case "10_field":
+            case "10_field" -> keys.stream().filter(key -> count.getAndIncrement() % 5 == 0).limit(10).collect(Collectors.toSet());
-                return keys.stream().filter(key -> count.getAndIncrement() % 5 == 0).limit(10).collect(Collectors.toSet());
+            case "half_field" -> keys.stream().filter(key -> count.getAndIncrement() % 2 == 0).collect(Collectors.toSet());
-            case "half_field":
+            case "all_field" -> new HashSet<>(keys);
-                return keys.stream().filter(key -> count.getAndIncrement() % 2 == 0).collect(Collectors.toSet());
+            case "wildcard_field" -> new HashSet<>(Arrays.asList("*stats"));
-            case "all_field":
+            case "10_wildcard_field" -> Set.of(
-                return new HashSet<>(keys);
-            case "wildcard_field":
-                return new HashSet<>(Arrays.asList("*stats"));
-            case "10_wildcard_field":
-                return Set.of(
                 "*stats.nodes*",
                 "*stats.ind*",
                 "*sta*.shards",
@@ -109,9 +96,8 @@ public class FilterContentBenchmark {
                 inclusive ? "*stats.**.threads" : "*stats.*.threads",
                 "*source_node.t*"
             );
-            default:
+            default -> throw new IllegalArgumentException("Unknown type [" + type + "]");
-                throw new IllegalArgumentException("Unknown type [" + type + "]");
+        };
-        }
     }
 
     @Benchmark

build-tools-internal/src/main/java/org/elasticsearch/gradle/internal/SymbolicLinkPreservingTar.java

@@ -44,18 +44,11 @@ public class SymbolicLinkPreservingTar extends Tar {
 
     @Override
     protected CopyAction createCopyAction() {
-        final ArchiveOutputStreamFactory compressor;
+        final ArchiveOutputStreamFactory compressor = switch (getCompression()) {
-        switch (getCompression()) {
+            case BZIP2 -> Bzip2Archiver.getCompressor();
-            case BZIP2:
+            case GZIP -> GzipArchiver.getCompressor();
-                compressor = Bzip2Archiver.getCompressor();
+            default -> new SimpleCompressor();
-                break;
+        };
-            case GZIP:
-                compressor = GzipArchiver.getCompressor();
-                break;
-            default:
-                compressor = new SimpleCompressor();
-                break;
-        }
         return new SymbolicLinkPreservingTarCopyAction(getArchiveFile(), compressor, isPreserveFileTimestamps());
     }
 

build-tools-internal/src/main/java/org/elasticsearch/gradle/internal/docker/TransformLog4jConfigFilter.java

@@ -87,23 +87,17 @@ public class TransformLog4jConfigFilter extends FilterReader {
                 }
 
                 switch (keyParts[2]) {
-                    case "type":
+                    case "type" -> {
                         if (value.equals("RollingFile")) {
                             value = "Console";
                         }
                         line = key + " = " + value;
-                        break;
+                    }
-
+                    case "fileName", "filePattern", "policies", "strategy" -> {
-                    case "fileName":
-                    case "filePattern":
-                    case "policies":
-                    case "strategy":
                         // No longer applicable. Omit it.
                         skipNext = line.endsWith("\\");
                         continue;
-
+                    }
-                    default:
-                        break;
                 }
             } else if (line.startsWith("rootLogger.appenderRef")) {
                 String[] parts = line.split("\\s*=\\s*");

build-tools/src/main/java/org/elasticsearch/gradle/Architecture.java

@@ -21,15 +21,11 @@ public enum Architecture {
 
     public static Architecture current() {
         final String architecture = System.getProperty("os.arch", "");
-        switch (architecture) {
+        return switch (architecture) {
-            case "amd64":
+            case "amd64", "x86_64" -> X64;
-            case "x86_64":
+            case "aarch64" -> AARCH64;
-                return X64;
+            default -> throw new IllegalArgumentException("can not determine architecture from [" + architecture + "]");
-            case "aarch64":
+        };
-                return AARCH64;
-            default:
-                throw new IllegalArgumentException("can not determine architecture from [" + architecture + "]");
-        }
     }
 
 }

client/benchmark/src/main/java/org/elasticsearch/client/benchmark/AbstractBenchmark.java

@@ -36,16 +36,12 @@ public abstract class AbstractBenchmark<T extends Closeable> {
             System.exit(1);
         }
         switch (args[0]) {
-            case "search":
+            case "search" -> runSearchBenchmark(args);
-                runSearchBenchmark(args);
+            case "bulk" -> runBulkIndexBenchmark(args);
-                break;
+            default -> {
-            case "bulk":
-                runBulkIndexBenchmark(args);
-                break;
-            default:
                 System.err.println("Unknown benchmark type [" + args[0] + "]");
                 System.exit(1);
-
+            }
         }
 
     }

client/benchmark/src/main/java/org/elasticsearch/client/benchmark/BenchmarkMain.java

@@ -16,15 +16,14 @@ public class BenchmarkMain {
     @SuppressForbidden(reason = "system out is ok for a command line tool")
     public static void main(String[] args) throws Exception {
         String type = args[0];
-        AbstractBenchmark<?> benchmark = null;
+        AbstractBenchmark<?> benchmark = switch (type) {
-        switch (type) {
+            case "rest" -> new RestClientBenchmark();
-            case "rest":
+            default -> {
-                benchmark = new RestClientBenchmark();
-                break;
-            default:
                 System.err.println("Unknown client type [" + type + "]");
                 System.exit(1);
+                yield null;
             }
+        };
         benchmark.run(Arrays.copyOfRange(args, 1, args.length));
     }
 }

client/rest-high-level/src/main/java/org/elasticsearch/client/ccr/FollowInfoResponse.java

@@ -163,14 +163,11 @@ public final class FollowInfoResponse {
         }
 
         public static Status fromString(String value) {
-            switch (value) {
+            return switch (value) {
-                case "active":
+                case "active" -> Status.ACTIVE;
-                    return Status.ACTIVE;
+                case "paused" -> Status.PAUSED;
-                case "paused":
+                default -> throw new IllegalArgumentException("unexpected status value [" + value + "]");
-                    return Status.PAUSED;
+            };
-                default:
-                    throw new IllegalArgumentException("unexpected status value [" + value + "]");
-            }
         }
     }
 }

client/rest-high-level/src/main/java/org/elasticsearch/client/indices/GetIndexResponse.java

@@ -149,20 +149,11 @@ public class GetIndexResponse {
             parser.nextToken();
             if (parser.currentToken() == Token.START_OBJECT) {
                 switch (parser.currentName()) {
-                    case "aliases":
+                    case "aliases" -> indexAliases = parseAliases(parser);
-                        indexAliases = parseAliases(parser);
+                    case "mappings" -> indexMappings = parseMappings(parser);
-                        break;
+                    case "settings" -> indexSettings = Settings.fromXContent(parser);
-                    case "mappings":
+                    case "defaults" -> indexDefaultSettings = Settings.fromXContent(parser);
-                        indexMappings = parseMappings(parser);
+                    default -> parser.skipChildren();
-                        break;
-                    case "settings":
-                        indexSettings = Settings.fromXContent(parser);
-                        break;
-                    case "defaults":
-                        indexDefaultSettings = Settings.fromXContent(parser);
-                        break;
-                    default:
-                        parser.skipChildren();
                 }
             } else if (parser.currentToken() == Token.VALUE_STRING) {
                 if (parser.currentName().equals("data_stream")) {

client/rest-high-level/src/main/java/org/elasticsearch/client/license/LicenseStatus.java

@@ -27,15 +27,11 @@ public enum LicenseStatus {
     }
 
     public static LicenseStatus fromString(String value) {
-        switch (value) {
+        return switch (value) {
-            case "active":
+            case "active" -> ACTIVE;
-                return ACTIVE;
+            case "invalid" -> INVALID;
-            case "invalid":
+            case "expired" -> EXPIRED;
-                return INVALID;
+            default -> throw new IllegalArgumentException("unknown license status [" + value + "]");
-            case "expired":
+        };
-                return EXPIRED;
-            default:
-                throw new IllegalArgumentException("unknown license status [" + value + "]");
-        }
     }
 }

client/rest-high-level/src/main/java/org/elasticsearch/client/license/LicensesStatus.java

@@ -42,15 +42,11 @@ public enum LicensesStatus {
     }
 
     public static LicensesStatus fromString(String value) {
-        switch (value) {
+        return switch (value) {
-            case "valid":
+            case "valid" -> VALID;
-                return VALID;
+            case "invalid" -> INVALID;
-            case "invalid":
+            case "expired" -> EXPIRED;
-                return INVALID;
+            default -> throw new IllegalArgumentException("unknown licenses status [" + value + "]");
-            case "expired":
+        };
-                return EXPIRED;
-            default:
-                throw new IllegalArgumentException("unknown licenses status [" + value + "]");
-        }
     }
 }

client/rest-high-level/src/main/java/org/elasticsearch/client/security/support/expressiondsl/parser/RoleMapperExpressionParser.java

@@ -164,25 +164,16 @@ public final class RoleMapperExpressionParser {
     }
 
     private Object parseFieldValue(XContentParser parser) throws IOException {
-        switch (parser.currentToken()) {
+        return switch (parser.currentToken()) {
-            case VALUE_STRING:
+            case VALUE_STRING -> parser.text();
-                return parser.text();
+            case VALUE_BOOLEAN -> parser.booleanValue();
-
+            case VALUE_NUMBER -> parser.longValue();
-            case VALUE_BOOLEAN:
+            case VALUE_NULL -> null;
-                return parser.booleanValue();
+            default -> throw new ElasticsearchParseException(
-
-            case VALUE_NUMBER:
-                return parser.longValue();
-
-            case VALUE_NULL:
-                return null;
-
-            default:
-                throw new ElasticsearchParseException(
                 "failed to parse rules expression. expected a field value but found [{}] instead",
                 parser.currentToken()
             );
-        }
+        };
     }
 
 }

client/rest-high-level/src/main/java/org/elasticsearch/client/transform/transforms/pivot/GroupConfig.java

@@ -75,24 +75,17 @@ public class GroupConfig implements ToXContentObject {
                 continue;
             }
 
-            SingleGroupSource groupSource = null;
+            SingleGroupSource groupSource = switch (groupType) {
-            switch (groupType) {
+                case "terms" -> TermsGroupSource.fromXContent(parser);
-                case "terms":
+                case "histogram" -> HistogramGroupSource.fromXContent(parser);
-                    groupSource = TermsGroupSource.fromXContent(parser);
+                case "date_histogram" -> DateHistogramGroupSource.fromXContent(parser);
-                    break;
+                case "geotile_grid" -> GeoTileGroupSource.fromXContent(parser);
-                case "histogram":
+                default -> {
-                    groupSource = HistogramGroupSource.fromXContent(parser);
-                    break;
-                case "date_histogram":
-                    groupSource = DateHistogramGroupSource.fromXContent(parser);
-                    break;
-                case "geotile_grid":
-                    groupSource = GeoTileGroupSource.fromXContent(parser);
-                    break;
-                default:
                     // not a valid group source. Consume up to the dest field end object
                     consumeUntilEndObject(parser, 2);
+                    yield null;
                 }
+            };
 
             if (groupSource != null) {
                 groups.put(destinationFieldName, groupSource);

client/rest-high-level/src/test/java/org/elasticsearch/client/ClusterRequestConvertersTests.java

@@ -69,29 +69,28 @@ public class ClusterRequestConvertersTests extends ESTestCase {
         String timeout = ESTestCase.randomTimeValue();
         String masterTimeout = ESTestCase.randomTimeValue();
         switch (timeoutType) {
-            case "timeout":
+            case "timeout" -> {
                 healthRequest.timeout(timeout);
                 expectedParams.put("timeout", timeout);
                 // If Master Timeout wasn't set it uses the same value as Timeout
                 expectedParams.put("master_timeout", timeout);
-                break;
+            }
-            case "masterTimeout":
+            case "masterTimeout" -> {
                 expectedParams.put("timeout", "30s");
                 healthRequest.masterNodeTimeout(masterTimeout);
                 expectedParams.put("master_timeout", masterTimeout);
-                break;
+            }
-            case "both":
+            case "both" -> {
                 healthRequest.timeout(timeout);
                 expectedParams.put("timeout", timeout);
                 healthRequest.masterNodeTimeout(timeout);
                 expectedParams.put("master_timeout", timeout);
-                break;
+            }
-            case "none":
+            case "none" -> {
                 expectedParams.put("timeout", "30s");
                 expectedParams.put("master_timeout", "30s");
-                break;
+            }
-            default:
+            default -> throw new UnsupportedOperationException();
-                throw new UnsupportedOperationException();
         }
         RequestConvertersTests.setRandomWaitForActiveShards(healthRequest::waitForActiveShards, ActiveShardCount.NONE, expectedParams);
         if (ESTestCase.randomBoolean()) {

client/rest-high-level/src/test/java/org/elasticsearch/client/RollupIT.java

@@ -356,20 +356,11 @@ public class RollupIT extends ESRestHighLevelClientTestCase {
         List<Map<String, Object>> timestampCaps = fieldCaps.get("date").getAggs();
         for (Map.Entry<String, Object> entry : timestampCaps.get(0).entrySet()) {
             switch (entry.getKey()) {
-                case "agg":
+                case "agg" -> assertThat(entry.getValue(), equalTo("date_histogram"));
-                    assertThat(entry.getValue(), equalTo("date_histogram"));
+                case "delay" -> assertThat(entry.getValue(), equalTo("foo"));
-                    break;
+                case "calendar_interval" -> assertThat(entry.getValue(), equalTo("1d"));
-                case "delay":
+                case "time_zone" -> assertThat(entry.getValue(), equalTo("UTC"));
-                    assertThat(entry.getValue(), equalTo("foo"));
+                default -> fail("Unknown field cap: [" + entry.getKey() + "]");
-                    break;
-                case "calendar_interval":
-                    assertThat(entry.getValue(), equalTo("1d"));
-                    break;
-                case "time_zone":
-                    assertThat(entry.getValue(), equalTo("UTC"));
-                    break;
-                default:
-                    fail("Unknown field cap: [" + entry.getKey() + "]");
             }
         }
 
@@ -471,20 +462,11 @@ public class RollupIT extends ESRestHighLevelClientTestCase {
         List<Map<String, Object>> timestampCaps = fieldCaps.get("date").getAggs();
         for (Map.Entry<String, Object> entry : timestampCaps.get(0).entrySet()) {
             switch (entry.getKey()) {
-                case "agg":
+                case "agg" -> assertThat(entry.getValue(), equalTo("date_histogram"));
-                    assertThat(entry.getValue(), equalTo("date_histogram"));
+                case "delay" -> assertThat(entry.getValue(), equalTo("foo"));
-                    break;
+                case "calendar_interval" -> assertThat(entry.getValue(), equalTo("1d"));
-                case "delay":
+                case "time_zone" -> assertThat(entry.getValue(), equalTo("UTC"));
-                    assertThat(entry.getValue(), equalTo("foo"));
+                default -> fail("Unknown field cap: [" + entry.getKey() + "]");
-                    break;
-                case "calendar_interval":
-                    assertThat(entry.getValue(), equalTo("1d"));
-                    break;
-                case "time_zone":
-                    assertThat(entry.getValue(), equalTo("UTC"));
-                    break;
-                default:
-                    fail("Unknown field cap: [" + entry.getKey() + "]");
             }
         }
 

client/rest-high-level/src/test/java/org/elasticsearch/client/XPackRequestConvertersTests.java

@@ -27,19 +27,16 @@ public class XPackRequestConvertersTests extends ESTestCase {
         }
         int option = ESTestCase.between(0, 2);
         switch (option) {
-            case 0:
+            case 0 -> infoRequest.setCategories(EnumSet.allOf(XPackInfoRequest.Category.class));
-                infoRequest.setCategories(EnumSet.allOf(XPackInfoRequest.Category.class));
+            case 1 -> {
-                break;
-            case 1:
                 infoRequest.setCategories(EnumSet.of(XPackInfoRequest.Category.FEATURES));
                 expectedParams.put("categories", "features");
-                break;
+            }
-            case 2:
+            case 2 -> {
                 infoRequest.setCategories(EnumSet.of(XPackInfoRequest.Category.FEATURES, XPackInfoRequest.Category.BUILD));
                 expectedParams.put("categories", "build,features");
-                break;
+            }
-            default:
+            default -> throw new IllegalArgumentException("invalid option [" + option + "]");
-                throw new IllegalArgumentException("invalid option [" + option + "]");
         }
 
         Request request = XPackRequestConverters.info(infoRequest);

client/rest-high-level/src/test/java/org/elasticsearch/client/eql/EqlSearchResponseTests.java

@@ -116,17 +116,19 @@ public class EqlSearchResponseTests extends AbstractResponseTestCase<
 
     private static Tuple<DocumentField, DocumentField> randomDocumentField(XContentType xType) {
         switch (randomIntBetween(0, 2)) {
-            case 0:
+            case 0 -> {
                 String fieldName = randomAlphaOfLengthBetween(3, 10);
                 Tuple<List<Object>, List<Object>> tuple = RandomObjects.randomStoredFieldValues(random(), xType);
                 DocumentField input = new DocumentField(fieldName, tuple.v1());
                 DocumentField expected = new DocumentField(fieldName, tuple.v2());
                 return Tuple.tuple(input, expected);
-            case 1:
+            }
+            case 1 -> {
                 List<Object> listValues = randomList(1, 5, () -> randomList(1, 5, ESTestCase::randomInt));
                 DocumentField listField = new DocumentField(randomAlphaOfLength(5), listValues);
                 return Tuple.tuple(listField, listField);
-            case 2:
+            }
+            case 2 -> {
                 List<Object> objectValues = randomList(
                     1,
                     5,
@@ -141,8 +143,8 @@ public class EqlSearchResponseTests extends AbstractResponseTestCase<
                 );
                 DocumentField objectField = new DocumentField(randomAlphaOfLength(5), objectValues);
                 return Tuple.tuple(objectField, objectField);
-            default:
+            }
-                throw new IllegalStateException();
+            default -> throw new IllegalStateException();
         }
     }
 
@@ -212,14 +214,11 @@ public class EqlSearchResponseTests extends AbstractResponseTestCase<
 
     public static org.elasticsearch.xpack.eql.action.EqlSearchResponse createRandomInstance(TotalHits totalHits, XContentType xType) {
         int type = between(0, 1);
-        switch (type) {
+        return switch (type) {
-            case 0:
+            case 0 -> createRandomEventsResponse(totalHits, xType);
-                return createRandomEventsResponse(totalHits, xType);
+            case 1 -> createRandomSequencesResponse(totalHits, xType);
-            case 1:
+            default -> null;
-                return createRandomSequencesResponse(totalHits, xType);
+        };
-            default:
-                return null;
-        }
     }
 
     @Override

client/rest-high-level/src/test/java/org/elasticsearch/client/ilm/ExplainLifecycleRequestTests.java

@@ -49,15 +49,12 @@ public class ExplainLifecycleRequestTests extends ESTestCase {
         String[] indices = instance.getIndices();
         IndicesOptions indicesOptions = instance.indicesOptions();
         switch (between(0, 1)) {
-            case 0:
+            case 0 -> indices = randomValueOtherThanMany(
-                indices = randomValueOtherThanMany(
                 i -> Arrays.equals(i, instance.getIndices()),
                 () -> generateRandomStringArray(20, 10, false, false)
             );
-                break;
+            case 1 -> indicesOptions = randomValueOtherThan(
-            case 1:
+                instance.indicesOptions(),
-                indicesOptions = randomValueOtherThan(
-                    indicesOptions,
                 () -> IndicesOptions.fromOptions(
                     randomBoolean(),
                     randomBoolean(),
@@ -69,9 +66,7 @@ public class ExplainLifecycleRequestTests extends ESTestCase {
                     randomBoolean()
                 )
             );
-                break;
+            default -> throw new AssertionError("Illegal randomisation branch");
-            default:
-                throw new AssertionError("Illegal randomisation branch");
         }
         ExplainLifecycleRequest newRequest = new ExplainLifecycleRequest(indices);
         newRequest.indicesOptions(indicesOptions);

client/rest-high-level/src/test/java/org/elasticsearch/client/ilm/LifecyclePolicyTests.java

@@ -226,60 +226,37 @@ public class LifecyclePolicyTests extends AbstractXContentTestCase<LifecyclePoli
         List<String> phaseNames = Arrays.asList("hot", "warm", "cold", "delete");
         Map<String, Phase> phases = new HashMap<>(phaseNames.size());
         Function<String, Set<String>> validActions = (phase) -> {
-            switch (phase) {
+            return switch (phase) {
-                case "hot":
+                case "hot" -> VALID_HOT_ACTIONS;
-                    return VALID_HOT_ACTIONS;
+                case "warm" -> VALID_WARM_ACTIONS;
-                case "warm":
+                case "cold" -> VALID_COLD_ACTIONS;
-                    return VALID_WARM_ACTIONS;
+                case "delete" -> VALID_DELETE_ACTIONS;
-                case "cold":
+                default -> throw new IllegalArgumentException("invalid phase [" + phase + "]");
-                    return VALID_COLD_ACTIONS;
+            };
-                case "delete":
-                    return VALID_DELETE_ACTIONS;
-                default:
-                    throw new IllegalArgumentException("invalid phase [" + phase + "]");
-            }
         };
         Function<String, Boolean> allowEmptyActions = (phase) -> {
-            switch (phase) {
+            return switch (phase) {
-                case "hot":
+                case "hot", "warm", "cold" -> true;
-                case "warm":
+                case "delete" -> false;
-                case "cold":
+                default -> throw new IllegalArgumentException("invalid phase [" + phase + "]");
-                    return true;
+            };
-                case "delete":
-                    return false;
-                default:
-                    throw new IllegalArgumentException("invalid phase [" + phase + "]");
-            }
         };
         Function<String, LifecycleAction> randomAction = (action) -> {
-            switch (action) {
+            return switch (action) {
-                case AllocateAction.NAME:
+                case AllocateAction.NAME -> AllocateActionTests.randomInstance();
-                    return AllocateActionTests.randomInstance();
+                case DeleteAction.NAME -> new DeleteAction();
-                case DeleteAction.NAME:
+                case ForceMergeAction.NAME -> ForceMergeActionTests.randomInstance();
-                    return new DeleteAction();
+                case ReadOnlyAction.NAME -> new ReadOnlyAction();
-                case ForceMergeAction.NAME:
+                case RolloverAction.NAME -> RolloverActionTests.randomInstance();
-                    return ForceMergeActionTests.randomInstance();
+                case ShrinkAction.NAME -> ShrinkActionTests.randomInstance();
-                case ReadOnlyAction.NAME:
+                case FreezeAction.NAME -> new FreezeAction();
-                    return new ReadOnlyAction();
+                case WaitForSnapshotAction.NAME -> WaitForSnapshotActionTests.randomInstance();
-                case RolloverAction.NAME:
+                case SetPriorityAction.NAME -> SetPriorityActionTests.randomInstance();
-                    return RolloverActionTests.randomInstance();
+                case UnfollowAction.NAME -> new UnfollowAction();
-                case ShrinkAction.NAME:
+                case SearchableSnapshotAction.NAME -> new SearchableSnapshotAction("repo", randomBoolean());
-                    return ShrinkActionTests.randomInstance();
+                case MigrateAction.NAME -> new MigrateAction(randomBoolean());
-                case FreezeAction.NAME:
+                default -> throw new IllegalArgumentException("invalid action [" + action + "]");
-                    return new FreezeAction();
+            };
-                case WaitForSnapshotAction.NAME:
-                    return WaitForSnapshotActionTests.randomInstance();
-                case SetPriorityAction.NAME:
-                    return SetPriorityActionTests.randomInstance();
-                case UnfollowAction.NAME:
-                    return new UnfollowAction();
-                case SearchableSnapshotAction.NAME:
-                    return new SearchableSnapshotAction("repo", randomBoolean());
-                case MigrateAction.NAME:
-                    return new MigrateAction(randomBoolean());
-                default:
-                    throw new IllegalArgumentException("invalid action [" + action + "]");
-            }
         };
         TimeValue prev = null;
         boolean searchableSnapshotSeen = false;
@@ -318,33 +295,20 @@ public class LifecyclePolicyTests extends AbstractXContentTestCase<LifecyclePoli
     }
 
     private LifecycleAction getTestAction(String actionName) {
-        switch (actionName) {
+        return switch (actionName) {
-            case AllocateAction.NAME:
+            case AllocateAction.NAME -> AllocateActionTests.randomInstance();
-                return AllocateActionTests.randomInstance();
+            case DeleteAction.NAME -> new DeleteAction();
-            case DeleteAction.NAME:
+            case ForceMergeAction.NAME -> ForceMergeActionTests.randomInstance();
-                return new DeleteAction();
+            case ReadOnlyAction.NAME -> new ReadOnlyAction();
-            case ForceMergeAction.NAME:
+            case RolloverAction.NAME -> RolloverActionTests.randomInstance();
-                return ForceMergeActionTests.randomInstance();
+            case ShrinkAction.NAME -> ShrinkActionTests.randomInstance();
-            case ReadOnlyAction.NAME:
+            case FreezeAction.NAME -> new FreezeAction();
-                return new ReadOnlyAction();
+            case WaitForSnapshotAction.NAME -> WaitForSnapshotActionTests.randomInstance();
-            case RolloverAction.NAME:
+            case SetPriorityAction.NAME -> SetPriorityActionTests.randomInstance();
-                return RolloverActionTests.randomInstance();
+            case SearchableSnapshotAction.NAME -> SearchableSnapshotActionTests.randomInstance();
-            case ShrinkAction.NAME:
+            case UnfollowAction.NAME -> new UnfollowAction();
-                return ShrinkActionTests.randomInstance();
+            case MigrateAction.NAME -> new MigrateAction(randomBoolean());
-            case FreezeAction.NAME:
+            default -> throw new IllegalArgumentException("unsupported phase action [" + actionName + "]");
-                return new FreezeAction();
+        };
-            case WaitForSnapshotAction.NAME:
-                return WaitForSnapshotActionTests.randomInstance();
-            case SetPriorityAction.NAME:
-                return SetPriorityActionTests.randomInstance();
-            case SearchableSnapshotAction.NAME:
-                return SearchableSnapshotActionTests.randomInstance();
-            case UnfollowAction.NAME:
-                return new UnfollowAction();
-            case MigrateAction.NAME:
-                return new MigrateAction(randomBoolean());
-            default:
-                throw new IllegalArgumentException("unsupported phase action [" + actionName + "]");
-        }
     }
 }

client/rest-high-level/src/test/java/org/elasticsearch/client/ml/EvaluateDataFrameResponseTests.java

@@ -27,16 +27,20 @@ import org.elasticsearch.xcontent.XContentParser;
 import java.io.IOException;
 import java.util.Arrays;
 import java.util.List;
+import java.util.Locale;
 import java.util.function.Predicate;
 
 public class EvaluateDataFrameResponseTests extends AbstractXContentTestCase<EvaluateDataFrameResponse> {
+    private enum Evaluation {
+        OUTLIER_DETECTION,
+        CLASSIFICATION,
+        REGRESSION
+    }
 
     public static EvaluateDataFrameResponse randomResponse() {
         String evaluationName = randomFrom(OutlierDetection.NAME, Classification.NAME, Regression.NAME);
-        List<EvaluationMetric.Result> metrics;
+        List<EvaluationMetric.Result> metrics = switch (Evaluation.valueOf(evaluationName.toUpperCase(Locale.ROOT))) {
-        switch (evaluationName) {
+            case OUTLIER_DETECTION -> randomSubsetOf(
-            case OutlierDetection.NAME:
-                metrics = randomSubsetOf(
                 Arrays.asList(
                     AucRocResultTests.randomResult(),
                     PrecisionMetricResultTests.randomResult(),
@@ -44,14 +48,10 @@ public class EvaluateDataFrameResponseTests extends AbstractXContentTestCase<Eva
                     ConfusionMatrixMetricResultTests.randomResult()
                 )
             );
-                break;
+            case REGRESSION -> randomSubsetOf(
-            case Regression.NAME:
-                metrics = randomSubsetOf(
                 Arrays.asList(MeanSquaredErrorMetricResultTests.randomResult(), RSquaredMetricResultTests.randomResult())
             );
-                break;
+            case CLASSIFICATION -> randomSubsetOf(
-            case Classification.NAME:
-                metrics = randomSubsetOf(
                 Arrays.asList(
                     AucRocResultTests.randomResult(),
                     AccuracyMetricResultTests.randomResult(),
@@ -60,10 +60,7 @@ public class EvaluateDataFrameResponseTests extends AbstractXContentTestCase<Eva
                     MulticlassConfusionMatrixMetricResultTests.randomResult()
                 )
             );
-                break;
+        };
-            default:
-                throw new AssertionError("Please add missing \"case\" variant to the \"switch\" statement");
-        }
         return new EvaluateDataFrameResponse(evaluationName, metrics);
     }
 

client/rest-high-level/src/test/java/org/elasticsearch/client/rollup/job/config/DateHistogramGroupConfigTests.java

@@ -82,18 +82,14 @@ public class DateHistogramGroupConfigTests extends AbstractXContentTestCase<Date
         final DateHistogramInterval delay = randomBoolean() ? new DateHistogramInterval(randomPositiveTimeValue()) : null;
         final String timezone = randomBoolean() ? randomZone().toString() : null;
         int i = randomIntBetween(0, 2);
-        final DateHistogramInterval interval;
+        final DateHistogramInterval interval = switch (i) {
-        switch (i) {
+            case 1 -> new DateHistogramInterval(randomTimeValue(1, 1, "m", "h", "d", "w"));
-            case 0:
+            default -> new DateHistogramInterval(randomPositiveTimeValue());
-                interval = new DateHistogramInterval(randomPositiveTimeValue());
+        };
-                return new DateHistogramGroupConfig.FixedInterval(field, interval, delay, timezone);
+        return switch (i) {
-            case 1:
+            case 0 -> new DateHistogramGroupConfig.FixedInterval(field, interval, delay, timezone);
-                interval = new DateHistogramInterval(randomTimeValue(1, 1, "m", "h", "d", "w"));
+            case 1 -> new DateHistogramGroupConfig.CalendarInterval(field, interval, delay, timezone);
-                return new DateHistogramGroupConfig.CalendarInterval(field, interval, delay, timezone);
+            default -> new DateHistogramGroupConfig(field, interval, delay, timezone);
-            default:
+        };
-                interval = new DateHistogramInterval(randomPositiveTimeValue());
-                return new DateHistogramGroupConfig(field, interval, delay, timezone);
-        }
-
     }
 }

client/rest-high-level/src/test/java/org/elasticsearch/client/security/ClearServiceAccountTokenCacheRequestTests.java

@@ -48,21 +48,18 @@ public class ClearServiceAccountTokenCacheRequestTests extends ESTestCase {
     }
 
     private ClearServiceAccountTokenCacheRequest mutateInstance(ClearServiceAccountTokenCacheRequest request) {
-        switch (randomIntBetween(0, 2)) {
+        return switch (randomIntBetween(0, 2)) {
-            case 0:
+            case 0 -> new ClearServiceAccountTokenCacheRequest(
-                return new ClearServiceAccountTokenCacheRequest(
                 randomValueOtherThan(request.getNamespace(), () -> randomAlphaOfLengthBetween(3, 8)),
                 request.getServiceName(),
                 request.getTokenNames()
             );
-            case 1:
+            case 1 -> new ClearServiceAccountTokenCacheRequest(
-                return new ClearServiceAccountTokenCacheRequest(
                 request.getNamespace(),
                 randomValueOtherThan(request.getServiceName(), () -> randomAlphaOfLengthBetween(3, 8)),
                 request.getTokenNames()
             );
-            default:
+            default -> new ClearServiceAccountTokenCacheRequest(
-                return new ClearServiceAccountTokenCacheRequest(
                 request.getNamespace(),
                 request.getServiceName(),
                 randomValueOtherThanMany(
@@ -70,6 +67,6 @@ public class ClearServiceAccountTokenCacheRequestTests extends ESTestCase {
                     () -> randomArray(0, 3, String[]::new, () -> randomAlphaOfLengthBetween(3, 8))
                 )
             );
-        }
+        };
     }
 }

client/rest-high-level/src/test/java/org/elasticsearch/client/security/CreateApiKeyResponseTests.java

@@ -86,27 +86,22 @@ public class CreateApiKeyResponseTests extends ESTestCase {
     }
 
     private static CreateApiKeyResponse mutateTestItem(CreateApiKeyResponse original) {
-        switch (randomIntBetween(0, 3)) {
+        return switch (randomIntBetween(0, 3)) {
-            case 0:
+            case 0 -> new CreateApiKeyResponse(randomAlphaOfLength(7), original.getId(), original.getKey(), original.getExpiration());
-                return new CreateApiKeyResponse(randomAlphaOfLength(7), original.getId(), original.getKey(), original.getExpiration());
+            case 1 -> new CreateApiKeyResponse(
-            case 1:
-                return new CreateApiKeyResponse(
                 original.getName(),
                 randomAlphaOfLengthBetween(4, 8),
                 original.getKey(),
                 original.getExpiration()
             );
-            case 2:
+            case 2 -> new CreateApiKeyResponse(
-                return new CreateApiKeyResponse(
                 original.getName(),
                 original.getId(),
                 UUIDs.randomBase64UUIDSecureString(),
                 original.getExpiration()
             );
-            case 3:
+            case 3 -> new CreateApiKeyResponse(original.getName(), original.getId(), original.getKey(), Instant.ofEpochMilli(150000));
-                return new CreateApiKeyResponse(original.getName(), original.getId(), original.getKey(), Instant.ofEpochMilli(150000));
+            default -> new CreateApiKeyResponse(randomAlphaOfLength(7), original.getId(), original.getKey(), original.getExpiration());
-            default:
+        };
-                return new CreateApiKeyResponse(randomAlphaOfLength(7), original.getId(), original.getKey(), original.getExpiration());
-        }
     }
 }

client/rest-high-level/src/test/java/org/elasticsearch/client/security/CreateServiceAccountTokenRequestTests.java

@@ -66,35 +66,31 @@ public class CreateServiceAccountTokenRequestTests extends ESTestCase {
     }
 
     private CreateServiceAccountTokenRequest mutateInstance(CreateServiceAccountTokenRequest request) {
-        switch (randomIntBetween(0, 3)) {
+        return switch (randomIntBetween(0, 3)) {
-            case 0:
+            case 0 -> new CreateServiceAccountTokenRequest(
-                return new CreateServiceAccountTokenRequest(
                 randomValueOtherThan(request.getNamespace(), () -> randomAlphaOfLengthBetween(3, 8)),
                 request.getServiceName(),
                 request.getTokenName(),
                 request.getRefreshPolicy()
             );
-            case 1:
+            case 1 -> new CreateServiceAccountTokenRequest(
-                return new CreateServiceAccountTokenRequest(
                 request.getNamespace(),
                 randomValueOtherThan(request.getServiceName(), () -> randomAlphaOfLengthBetween(3, 8)),
                 request.getTokenName(),
                 request.getRefreshPolicy()
             );
-            case 2:
+            case 2 -> new CreateServiceAccountTokenRequest(
-                return new CreateServiceAccountTokenRequest(
                 request.getNamespace(),
                 request.getServiceName(),
                 randomValueOtherThan(request.getTokenName(), () -> randomAlphaOfLengthBetween(3, 8)),
                 request.getRefreshPolicy()
             );
-            default:
+            default -> new CreateServiceAccountTokenRequest(
-                return new CreateServiceAccountTokenRequest(
                 request.getNamespace(),
                 request.getServiceName(),
                 request.getTokenName(),
                 randomValueOtherThan(request.getRefreshPolicy(), () -> randomFrom(RefreshPolicy.values()))
             );
-        }
+        };
     }
 }

client/rest-high-level/src/test/java/org/elasticsearch/client/security/DeleteServiceAccountTokenRequestTests.java

@@ -65,36 +65,32 @@ public class DeleteServiceAccountTokenRequestTests extends ESTestCase {
     }
 
     private DeleteServiceAccountTokenRequest mutateInstance(DeleteServiceAccountTokenRequest request) {
-        switch (randomIntBetween(0, 3)) {
+        return switch (randomIntBetween(0, 3)) {
-            case 0:
+            case 0 -> new DeleteServiceAccountTokenRequest(
-                return new DeleteServiceAccountTokenRequest(
                 randomValueOtherThan(request.getNamespace(), () -> randomAlphaOfLengthBetween(3, 8)),
                 request.getServiceName(),
                 request.getTokenName(),
                 request.getRefreshPolicy()
             );
-            case 1:
+            case 1 -> new DeleteServiceAccountTokenRequest(
-                return new DeleteServiceAccountTokenRequest(
                 request.getNamespace(),
                 randomValueOtherThan(request.getServiceName(), () -> randomAlphaOfLengthBetween(3, 8)),
                 request.getTokenName(),
                 request.getRefreshPolicy()
             );
-            case 2:
+            case 2 -> new DeleteServiceAccountTokenRequest(
-                return new DeleteServiceAccountTokenRequest(
                 request.getNamespace(),
                 request.getServiceName(),
                 randomValueOtherThan(request.getTokenName(), () -> randomAlphaOfLengthBetween(3, 8)),
                 request.getRefreshPolicy()
             );
-            default:
+            default -> new DeleteServiceAccountTokenRequest(
-                return new DeleteServiceAccountTokenRequest(
                 request.getNamespace(),
                 request.getServiceName(),
                 request.getTokenName(),
                 randomValueOtherThan(request.getRefreshPolicy(), () -> randomFrom(RefreshPolicy.values()))
             );
-        }
+        };
     }
 
 }

client/rest-high-level/src/test/java/org/elasticsearch/client/security/ExpressionRoleMappingTests.java

@@ -17,7 +17,6 @@ import org.elasticsearch.xcontent.XContentType;
 
 import java.io.IOException;
 import java.util.Collections;
-import java.util.HashMap;
 import java.util.Map;
 
 import static java.util.Collections.singletonList;
@@ -79,10 +78,8 @@ public class ExpressionRoleMappingTests extends ESTestCase {
     }
 
     private static ExpressionRoleMapping mutateTestItem(ExpressionRoleMapping original) throws IOException {
-        ExpressionRoleMapping mutated = null;
+        return switch (randomIntBetween(0, 5)) {
-        switch (randomIntBetween(0, 5)) {
+            case 0 -> new ExpressionRoleMapping(
-            case 0:
-                mutated = new ExpressionRoleMapping(
                 "namechanged",
                 FieldRoleMapperExpression.ofKeyValues("realm.name", "kerb1"),
                 singletonList("superuser"),
@@ -90,9 +87,7 @@ public class ExpressionRoleMappingTests extends ESTestCase {
                 null,
                 true
             );
-                break;
+            case 1 -> new ExpressionRoleMapping(
-            case 1:
-                mutated = new ExpressionRoleMapping(
                 "kerberosmapping",
                 FieldRoleMapperExpression.ofKeyValues("changed", "changed"),
                 singletonList("superuser"),
@@ -100,9 +95,7 @@ public class ExpressionRoleMappingTests extends ESTestCase {
                 null,
                 true
             );
-                break;
+            case 2 -> new ExpressionRoleMapping(
-            case 2:
-                mutated = new ExpressionRoleMapping(
                 "kerberosmapping",
                 FieldRoleMapperExpression.ofKeyValues("realm.name", "kerb1"),
                 singletonList("changed"),
@@ -110,21 +103,15 @@ public class ExpressionRoleMappingTests extends ESTestCase {
                 null,
                 true
             );
-                break;
+            case 3 -> new ExpressionRoleMapping(
-            case 3:
-                Map<String, Object> metadata = new HashMap<>();
-                metadata.put("a", "b");
-                mutated = new ExpressionRoleMapping(
                 "kerberosmapping",
                 FieldRoleMapperExpression.ofKeyValues("realm.name", "kerb1"),
                 singletonList("superuser"),
                 Collections.emptyList(),
-                    metadata,
+                Map.of("a", "b"),
                 true
             );
-                break;
+            case 4 -> new ExpressionRoleMapping(
-            case 4:
-                mutated = new ExpressionRoleMapping(
                 "kerberosmapping",
                 FieldRoleMapperExpression.ofKeyValues("realm.name", "kerb1"),
                 Collections.emptyList(),
@@ -132,9 +119,7 @@ public class ExpressionRoleMappingTests extends ESTestCase {
                 null,
                 true
             );
-                break;
+            case 5 -> new ExpressionRoleMapping(
-            case 5:
-                mutated = new ExpressionRoleMapping(
                 "kerberosmapping",
                 FieldRoleMapperExpression.ofKeyValues("realm.name", "kerb1"),
                 singletonList("superuser"),
@@ -142,8 +127,7 @@ public class ExpressionRoleMappingTests extends ESTestCase {
                 null,
                 false
             );
-                break;
+            default -> throw new UnsupportedOperationException();
-        }
+        };
-        return mutated;
     }
 }

client/rest-high-level/src/test/java/org/elasticsearch/client/security/GetApiKeyResponseTests.java

@@ -104,12 +104,10 @@ public class GetApiKeyResponseTests extends ESTestCase {
             "user-b",
             "realm-y"
         );
-        switch (randomIntBetween(0, 2)) {
+        return switch (randomIntBetween(0, 2)) {
-            case 0:
+            case 0 -> new GetApiKeyResponse(Arrays.asList(apiKeyInfo));
-                return new GetApiKeyResponse(Arrays.asList(apiKeyInfo));
+            default -> new GetApiKeyResponse(Arrays.asList(apiKeyInfo));
-            default:
+        };
-                return new GetApiKeyResponse(Arrays.asList(apiKeyInfo));
-        }
     }
 
     private static ApiKey createApiKeyInfo(

client/rest-high-level/src/test/java/org/elasticsearch/client/security/GetRoleMappingsResponseTests.java

@@ -107,11 +107,10 @@ public class GetRoleMappingsResponseTests extends ESTestCase {
     }
 
     private static GetRoleMappingsResponse mutateTestItem(GetRoleMappingsResponse original) {
-        GetRoleMappingsResponse mutated = null;
+        ExpressionRoleMapping originalRoleMapping = original.getMappings().get(0);
-        switch (randomIntBetween(0, 1)) {
+        return switch (randomIntBetween(0, 1)) {
-            case 0:
+            case 0 -> new GetRoleMappingsResponse(
-                final List<ExpressionRoleMapping> roleMappingsList1 = new ArrayList<>();
+                List.of(
-                roleMappingsList1.add(
                     new ExpressionRoleMapping(
                         "ldapmapping",
                         FieldRoleMapperExpression.ofGroups("cn=ipausers,cn=groups,cn=accounts,dc=ipademo,dc=local"),
@@ -120,13 +119,10 @@ public class GetRoleMappingsResponseTests extends ESTestCase {
                         null,
                         false
                     )
+                )
             );
-                mutated = new GetRoleMappingsResponse(roleMappingsList1);
+            default -> new GetRoleMappingsResponse(
-                break;
+                List.of(
-            case 1:
-                final List<ExpressionRoleMapping> roleMappingsList2 = new ArrayList<>();
-                ExpressionRoleMapping originalRoleMapping = original.getMappings().get(0);
-                roleMappingsList2.add(
                     new ExpressionRoleMapping(
                         originalRoleMapping.getName(),
                         FieldRoleMapperExpression.ofGroups("cn=ipausers,cn=groups,cn=accounts,dc=ipademo,dc=local"),
@@ -135,10 +131,8 @@ public class GetRoleMappingsResponseTests extends ESTestCase {
                         originalRoleMapping.getMetadata(),
                         originalRoleMapping.isEnabled() == false
                     )
+                )
             );
-                mutated = new GetRoleMappingsResponse(roleMappingsList2);
+        };
-                break;
-        }
-        return mutated;
     }
 }

client/rest-high-level/src/test/java/org/elasticsearch/client/security/GetServiceAccountCredentialsRequestTests.java

@@ -37,17 +37,15 @@ public class GetServiceAccountCredentialsRequestTests extends ESTestCase {
     }
 
     private GetServiceAccountCredentialsRequest mutateInstance(GetServiceAccountCredentialsRequest request) {
-        switch (randomIntBetween(0, 1)) {
+        return switch (randomIntBetween(0, 1)) {
-            case 0:
+            case 0 -> new GetServiceAccountCredentialsRequest(
-                return new GetServiceAccountCredentialsRequest(
                 randomValueOtherThan(request.getNamespace(), () -> randomAlphaOfLengthBetween(3, 8)),
                 request.getServiceName()
             );
-            default:
+            default -> new GetServiceAccountCredentialsRequest(
-                return new GetServiceAccountCredentialsRequest(
                 request.getNamespace(),
                 randomValueOtherThan(request.getServiceName(), () -> randomAlphaOfLengthBetween(3, 8))
             );
-        }
+        };
     }
 }

client/rest-high-level/src/test/java/org/elasticsearch/client/security/GetServiceAccountsRequestTests.java

@@ -54,17 +54,15 @@ public class GetServiceAccountsRequestTests extends ESTestCase {
     }
 
     private GetServiceAccountsRequest mutateInstance(GetServiceAccountsRequest request) {
-        switch (randomIntBetween(0, 1)) {
+        return switch (randomIntBetween(0, 1)) {
-            case 0:
+            case 0 -> new GetServiceAccountsRequest(
-                return new GetServiceAccountsRequest(
                 randomValueOtherThan(request.getNamespace(), () -> randomAlphaOfLengthBetween(3, 8)),
                 request.getServiceName()
             );
-            default:
+            default -> new GetServiceAccountsRequest(
-                return new GetServiceAccountsRequest(
                 request.getNamespace(),
                 randomValueOtherThan(request.getServiceName(), () -> randomAlphaOfLengthBetween(3, 8))
             );
-        }
+        };
     }
 }

client/rest-high-level/src/test/java/org/elasticsearch/client/security/GrantApiKeyRequestTests.java

@@ -96,14 +96,11 @@ public class GrantApiKeyRequestTests extends ESTestCase {
     }
 
     private GrantApiKeyRequest.Grant clone(GrantApiKeyRequest.Grant grant) {
-        switch (grant.getGrantType()) {
+        return switch (grant.getGrantType()) {
-            case "password":
+            case "password" -> GrantApiKeyRequest.Grant.passwordGrant(grant.getUsername(), grant.getPassword());
-                return GrantApiKeyRequest.Grant.passwordGrant(grant.getUsername(), grant.getPassword());
+            case "access_token" -> GrantApiKeyRequest.Grant.accessTokenGrant(grant.getAccessToken());
-            case "access_token":
+            default -> throw new IllegalArgumentException("Cannot clone grant: " + Strings.toString(grant));
-                return GrantApiKeyRequest.Grant.accessTokenGrant(grant.getAccessToken());
+        };
-            default:
-                throw new IllegalArgumentException("Cannot clone grant: " + Strings.toString(grant));
-        }
     }
 
     private CreateApiKeyRequest clone(CreateApiKeyRequest apiKeyRequest) {
@@ -117,16 +114,14 @@ public class GrantApiKeyRequestTests extends ESTestCase {
     }
 
     private static GrantApiKeyRequest mutateTestItem(GrantApiKeyRequest original) {
-        switch (randomIntBetween(0, 3)) {
+        return switch (randomIntBetween(0, 3)) {
-            case 0:
+            case 0 -> new GrantApiKeyRequest(
-                return new GrantApiKeyRequest(
                 original.getGrant().getGrantType().equals("password")
                     ? GrantApiKeyRequest.Grant.accessTokenGrant(randomAlphaOfLength(24))
                     : GrantApiKeyRequest.Grant.passwordGrant(randomAlphaOfLength(8), randomAlphaOfLengthBetween(6, 12).toCharArray()),
                 original.getApiKeyRequest()
             );
-            case 1:
+            case 1 -> new GrantApiKeyRequest(
-                return new GrantApiKeyRequest(
                 original.getGrant(),
                 new CreateApiKeyRequest(
                     randomAlphaOfLengthBetween(10, 15),
@@ -136,8 +131,7 @@ public class GrantApiKeyRequestTests extends ESTestCase {
                     original.getApiKeyRequest().getMetadata()
                 )
             );
-            case 2:
+            case 2 -> new GrantApiKeyRequest(
-                return new GrantApiKeyRequest(
                 original.getGrant(),
                 new CreateApiKeyRequest(
                     original.getApiKeyRequest().getName(),
@@ -147,8 +141,7 @@ public class GrantApiKeyRequestTests extends ESTestCase {
                     original.getApiKeyRequest().getMetadata()
                 )
             );
-            case 3:
+            case 3 -> new GrantApiKeyRequest(
-                return new GrantApiKeyRequest(
                 original.getGrant(),
                 new CreateApiKeyRequest(
                     original.getApiKeyRequest().getName(),
@@ -158,8 +151,7 @@ public class GrantApiKeyRequestTests extends ESTestCase {
                     randomValueOtherThan(original.getApiKeyRequest().getMetadata(), CreateApiKeyRequestTests::randomMetadata)
                 )
             );
-            default:
+            default -> new GrantApiKeyRequest(
-                return new GrantApiKeyRequest(
                 original.getGrant(),
                 new CreateApiKeyRequest(
                     original.getApiKeyRequest().getName(),
@@ -169,6 +161,6 @@ public class GrantApiKeyRequestTests extends ESTestCase {
                     original.getApiKeyRequest().getMetadata()
                 )
             );
-        }
+        };
     }
 }

client/rest-high-level/src/test/java/org/elasticsearch/client/security/InvalidateApiKeyResponseTests.java

@@ -114,27 +114,23 @@ public class InvalidateApiKeyResponseTests extends ESTestCase {
     }
 
     private static InvalidateApiKeyResponse mutateTestItem(InvalidateApiKeyResponse original) {
-        switch (randomIntBetween(0, 2)) {
+        return switch (randomIntBetween(0, 2)) {
-            case 0:
+            case 0 -> new InvalidateApiKeyResponse(
-                return new InvalidateApiKeyResponse(
                 Arrays.asList(randomArray(2, 5, String[]::new, () -> randomAlphaOfLength(5))),
                 original.getPreviouslyInvalidatedApiKeys(),
                 original.getErrors()
             );
-            case 1:
+            case 1 -> new InvalidateApiKeyResponse(original.getInvalidatedApiKeys(), Collections.emptyList(), original.getErrors());
-                return new InvalidateApiKeyResponse(original.getInvalidatedApiKeys(), Collections.emptyList(), original.getErrors());
+            case 2 -> new InvalidateApiKeyResponse(
-            case 2:
-                return new InvalidateApiKeyResponse(
                 original.getInvalidatedApiKeys(),
                 original.getPreviouslyInvalidatedApiKeys(),
                 Collections.emptyList()
             );
-            default:
+            default -> new InvalidateApiKeyResponse(
-                return new InvalidateApiKeyResponse(
                 Arrays.asList(randomArray(2, 5, String[]::new, () -> randomAlphaOfLength(5))),
                 original.getPreviouslyInvalidatedApiKeys(),
                 original.getErrors()
             );
-        }
+        };
     }
 }

client/rest-high-level/src/test/java/org/elasticsearch/client/security/InvalidateTokenRequestTests.java

@@ -72,18 +72,13 @@ public class InvalidateTokenRequestTests extends ESTestCase {
             : InvalidateTokenRequest.refreshToken(token);
         final EqualsHashCodeTestUtils.MutateFunction<InvalidateTokenRequest> mutate = r -> {
             int randomCase = randomIntBetween(1, 4);
-            switch (randomCase) {
+            return switch (randomCase) {
-                case 1:
+                case 1 -> InvalidateTokenRequest.refreshToken(randomAlphaOfLength(5));
-                    return InvalidateTokenRequest.refreshToken(randomAlphaOfLength(5));
+                case 2 -> InvalidateTokenRequest.accessToken(randomAlphaOfLength(5));
-                case 2:
+                case 3 -> InvalidateTokenRequest.realmTokens(randomAlphaOfLength(5));
-                    return InvalidateTokenRequest.accessToken(randomAlphaOfLength(5));
+                case 4 -> InvalidateTokenRequest.userTokens(randomAlphaOfLength(5));
-                case 3:
+                default -> new InvalidateTokenRequest(null, null, randomAlphaOfLength(5), randomAlphaOfLength(5));
-                    return InvalidateTokenRequest.realmTokens(randomAlphaOfLength(5));
+            };
-                case 4:
-                    return InvalidateTokenRequest.userTokens(randomAlphaOfLength(5));
-                default:
-                    return new InvalidateTokenRequest(null, null, randomAlphaOfLength(5), randomAlphaOfLength(5));
-            }
         };
         EqualsHashCodeTestUtils.checkEqualsAndHashCode(
             request,

client/rest-high-level/src/test/java/org/elasticsearch/client/security/KibanaEnrollmentResponseTests.java

@@ -63,29 +63,25 @@ public class KibanaEnrollmentResponseTests extends ESTestCase {
     }
 
     private static KibanaEnrollmentResponse mutateTestItem(KibanaEnrollmentResponse original) {
-        switch (randomIntBetween(0, 3)) {
+        return switch (randomIntBetween(0, 3)) {
-            case 0:
+            case 0 -> new KibanaEnrollmentResponse(
-                return new KibanaEnrollmentResponse(
                 randomAlphaOfLengthBetween(14, 20),
                 new SecureString(randomAlphaOfLengthBetween(71, 90).toCharArray()),
                 randomAlphaOfLength(52)
             );
-            case 1:
+            case 1 -> new KibanaEnrollmentResponse(
-                return new KibanaEnrollmentResponse(
                 original.getTokenName(),
                 new SecureString(randomAlphaOfLengthBetween(71, 90).toCharArray()),
                 randomAlphaOfLength(52)
             );
-            case 2:
+            case 2 -> new KibanaEnrollmentResponse(randomAlphaOfLengthBetween(14, 20), original.getTokenValue(), randomAlphaOfLength(52));
-                return new KibanaEnrollmentResponse(randomAlphaOfLengthBetween(14, 20), original.getTokenValue(), randomAlphaOfLength(52));
+            case 3 -> new KibanaEnrollmentResponse(
-            case 3:
-                return new KibanaEnrollmentResponse(
                 randomAlphaOfLengthBetween(14, 20),
                 new SecureString(randomAlphaOfLengthBetween(71, 90).toCharArray()),
                 original.getHttpCa()
             );
-        }
             // we never reach here
-        return null;
+            default -> null;
+        };
     }
 }

client/rest-high-level/src/test/java/org/elasticsearch/client/security/QueryApiKeyRequestTests.java

@@ -78,74 +78,61 @@ public class QueryApiKeyRequestTests extends ESTestCase {
     }
 
     private QueryApiKeyRequest mutateInstance(QueryApiKeyRequest request) {
-        switch (randomIntBetween(0, 5)) {
+        return switch (randomIntBetween(0, 5)) {
-            case 0:
+            case 0 -> new QueryApiKeyRequest(
-                return new QueryApiKeyRequest(
                 randomValueOtherThan(request.getQueryBuilder(), QueryApiKeyRequestTests::randomQueryBuilder),
                 request.getFrom(),
                 request.getSize(),
                 request.getFieldSortBuilders(),
                 request.getSearchAfterBuilder()
             );
-            case 1:
+            case 1 -> new QueryApiKeyRequest(
-                return new QueryApiKeyRequest(
                 request.getQueryBuilder(),
                 request.getFrom() + 1,
                 request.getSize(),
                 request.getFieldSortBuilders(),
                 request.getSearchAfterBuilder()
             );
-            case 2:
+            case 2 -> new QueryApiKeyRequest(
-                return new QueryApiKeyRequest(
                 request.getQueryBuilder(),
                 request.getFrom(),
                 request.getSize() + 1,
                 request.getFieldSortBuilders(),
                 request.getSearchAfterBuilder()
             );
-            case 3:
+            case 3 -> new QueryApiKeyRequest(
-                return new QueryApiKeyRequest(
                 request.getQueryBuilder(),
                 request.getFrom(),
                 request.getSize(),
                 randomValueOtherThan(request.getFieldSortBuilders(), QueryApiKeyRequestTests::randomFieldSortBuilders),
                 request.getSearchAfterBuilder()
             );
-            default:
+            default -> new QueryApiKeyRequest(
-                return new QueryApiKeyRequest(
                 request.getQueryBuilder(),
                 request.getFrom(),
                 request.getSize(),
                 request.getFieldSortBuilders(),
                 randomValueOtherThan(request.getSearchAfterBuilder(), QueryApiKeyRequestTests::randomSearchAfterBuilder)
             );
-
+        };
-        }
     }
 
     public static QueryBuilder randomQueryBuilder() {
-        switch (randomIntBetween(0, 5)) {
+        return switch (randomIntBetween(0, 5)) {
-            case 0:
+            case 0 -> QueryBuilders.matchAllQuery();
-                return QueryBuilders.matchAllQuery();
+            case 1 -> QueryBuilders.termQuery(
-            case 1:
-                return QueryBuilders.termQuery(
                 randomAlphaOfLengthBetween(3, 8),
                 randomFrom(randomAlphaOfLength(8), randomInt(), randomLong(), randomDouble(), randomFloat())
             );
-            case 2:
+            case 2 -> QueryBuilders.idsQuery().addIds(randomArray(1, 5, String[]::new, () -> randomAlphaOfLength(20)));
-                return QueryBuilders.idsQuery().addIds(randomArray(1, 5, String[]::new, () -> randomAlphaOfLength(20)));
+            case 3 -> QueryBuilders.prefixQuery(randomAlphaOfLengthBetween(3, 8), randomAlphaOfLengthBetween(3, 8));
-            case 3:
+            case 4 -> QueryBuilders.wildcardQuery(
-                return QueryBuilders.prefixQuery(randomAlphaOfLengthBetween(3, 8), randomAlphaOfLengthBetween(3, 8));
-            case 4:
-                return QueryBuilders.wildcardQuery(
                 randomAlphaOfLengthBetween(3, 8),
                 randomAlphaOfLengthBetween(0, 3) + "*" + randomAlphaOfLengthBetween(0, 3)
             );
-            case 5:
+            case 5 -> QueryBuilders.rangeQuery(randomAlphaOfLengthBetween(3, 8)).from(randomNonNegativeLong()).to(randomNonNegativeLong());
-                return QueryBuilders.rangeQuery(randomAlphaOfLengthBetween(3, 8)).from(randomNonNegativeLong()).to(randomNonNegativeLong());
+            default -> null;
-            default:
+        };
-                return null;
-        }
     }
 
     public static List<FieldSortBuilder> randomFieldSortBuilders() {

client/rest-high-level/src/test/java/org/elasticsearch/client/security/user/privileges/GlobalOperationPrivilegeTests.java

@@ -61,19 +61,15 @@ public class GlobalOperationPrivilegeTests extends ESTestCase {
     }
 
     private static GlobalOperationPrivilege mutateTestItem(GlobalOperationPrivilege original) {
-        switch (randomIntBetween(0, 2)) {
+        return switch (randomIntBetween(0, 2)) {
-            case 0:
+            case 0 -> new GlobalOperationPrivilege(randomAlphaOfLength(5), original.getOperation(), original.getRaw());
-                return new GlobalOperationPrivilege(randomAlphaOfLength(5), original.getOperation(), original.getRaw());
+            case 1 -> new GlobalOperationPrivilege(original.getCategory(), randomAlphaOfLength(5), original.getRaw());
-            case 1:
+            case 2 -> new GlobalOperationPrivilege(
-                return new GlobalOperationPrivilege(original.getCategory(), randomAlphaOfLength(5), original.getRaw());
-            case 2:
-                return new GlobalOperationPrivilege(
                 original.getCategory(),
                 original.getOperation(),
                 Collections.singletonMap(randomAlphaOfLength(4), randomAlphaOfLength(4))
             );
-            default:
+            default -> new GlobalOperationPrivilege(randomAlphaOfLength(5), original.getOperation(), original.getRaw());
-                return new GlobalOperationPrivilege(randomAlphaOfLength(5), original.getOperation(), original.getRaw());
+        };
-        }
     }
 }

client/rest-high-level/src/test/java/org/elasticsearch/client/transform/transforms/TransformConfigTests.java

@@ -72,23 +72,13 @@ public class TransformConfigTests extends AbstractXContentTestCase<TransformConf
     public static Map<String, Object> randomMetadata() {
         return randomMap(0, 10, () -> {
             String key = randomAlphaOfLengthBetween(1, 10);
-            Object value;
+            Object value = switch (randomIntBetween(0, 3)) {
-            switch (randomIntBetween(0, 3)) {
+                case 0 -> null;
-                case 0:
+                case 1 -> randomLong();
-                    value = null;
+                case 2 -> randomAlphaOfLengthBetween(1, 10);
-                    break;
+                case 3 -> randomMap(0, 10, () -> Tuple.tuple(randomAlphaOfLengthBetween(1, 10), randomAlphaOfLengthBetween(1, 10)));
-                case 1:
+                default -> throw new AssertionError();
-                    value = randomLong();
+            };
-                    break;
-                case 2:
-                    value = randomAlphaOfLengthBetween(1, 10);
-                    break;
-                case 3:
-                    value = randomMap(0, 10, () -> Tuple.tuple(randomAlphaOfLengthBetween(1, 10), randomAlphaOfLengthBetween(1, 10)));
-                    break;
-                default:
-                    throw new AssertionError();
-            }
             return Tuple.tuple(key, value);
         });
     }

client/rest-high-level/src/test/java/org/elasticsearch/client/transform/transforms/pivot/AggregationConfigTests.java

@@ -61,17 +61,13 @@ public class AggregationConfigTests extends AbstractXContentTestCase<Aggregation
 
     private static AggregationBuilder getRandomSupportedAggregation() {
         final int numberOfSupportedAggs = 4;
-        switch (randomIntBetween(1, numberOfSupportedAggs)) {
+        return switch (randomIntBetween(1, numberOfSupportedAggs)) {
-            case 1:
+            case 1 -> AggregationBuilders.avg(randomAlphaOfLengthBetween(1, 10)).field(randomAlphaOfLengthBetween(1, 10));
-                return AggregationBuilders.avg(randomAlphaOfLengthBetween(1, 10)).field(randomAlphaOfLengthBetween(1, 10));
+            case 2 -> AggregationBuilders.min(randomAlphaOfLengthBetween(1, 10)).field(randomAlphaOfLengthBetween(1, 10));
-            case 2:
+            case 3 -> AggregationBuilders.max(randomAlphaOfLengthBetween(1, 10)).field(randomAlphaOfLengthBetween(1, 10));
-                return AggregationBuilders.min(randomAlphaOfLengthBetween(1, 10)).field(randomAlphaOfLengthBetween(1, 10));
+            case 4 -> AggregationBuilders.sum(randomAlphaOfLengthBetween(1, 10)).field(randomAlphaOfLengthBetween(1, 10));
-            case 3:
+            default -> null;
-                return AggregationBuilders.max(randomAlphaOfLengthBetween(1, 10)).field(randomAlphaOfLengthBetween(1, 10));
+        };
-            case 4:
-                return AggregationBuilders.sum(randomAlphaOfLengthBetween(1, 10)).field(randomAlphaOfLengthBetween(1, 10));
-        }
 
-        return null;
     }
 }

client/rest-high-level/src/test/java/org/elasticsearch/client/transform/transforms/pivot/GroupConfigTests.java

@@ -34,24 +34,13 @@ public class GroupConfigTests extends AbstractXContentTestCase<GroupConfig> {
         for (int i = 0; i < randomIntBetween(1, 4); ++i) {
             String targetFieldName = randomAlphaOfLengthBetween(1, 20);
             if (names.add(targetFieldName)) {
-                SingleGroupSource groupBy = null;
                 SingleGroupSource.Type type = randomFrom(SingleGroupSource.Type.values());
-                switch (type) {
+                SingleGroupSource groupBy = switch (type) {
-                    case TERMS:
+                    case TERMS -> TermsGroupSourceTests.randomTermsGroupSource();
-                        groupBy = TermsGroupSourceTests.randomTermsGroupSource();
+                    case HISTOGRAM -> HistogramGroupSourceTests.randomHistogramGroupSource();
-                        break;
+                    case DATE_HISTOGRAM -> DateHistogramGroupSourceTests.randomDateHistogramGroupSource();
-                    case HISTOGRAM:
+                    case GEOTILE_GRID -> GeoTileGroupSourceTests.randomGeoTileGroupSource();
-                        groupBy = HistogramGroupSourceTests.randomHistogramGroupSource();
+                };
-                        break;
-                    case DATE_HISTOGRAM:
-                        groupBy = DateHistogramGroupSourceTests.randomDateHistogramGroupSource();
-                        break;
-                    case GEOTILE_GRID:
-                        groupBy = GeoTileGroupSourceTests.randomGeoTileGroupSource();
-                        break;
-                    default:
-                        fail("unknown group source type, please implement tests and add support here");
-                }
                 groups.put(targetFieldName, groupBy);
             }
         }

distribution/tools/plugin-cli/src/main/java/org/elasticsearch/plugins/cli/InstallPluginAction.java

@@ -264,15 +264,12 @@ public class InstallPluginAction implements Closeable {
 
     private static void handleInstallXPack(final Build.Flavor flavor) throws UserException {
         switch (flavor) {
-            case DEFAULT:
+            case DEFAULT -> throw new UserException(ExitCodes.CONFIG, "this distribution of Elasticsearch contains X-Pack by default");
-                throw new UserException(ExitCodes.CONFIG, "this distribution of Elasticsearch contains X-Pack by default");
+            case OSS -> throw new UserException(
-            case OSS:
-                throw new UserException(
                 ExitCodes.CONFIG,
                 "X-Pack is not available with the oss distribution; to use X-Pack features use the default distribution"
             );
-            case UNKNOWN:
+            case UNKNOWN -> throw new IllegalStateException("your distribution is broken");
-                throw new IllegalStateException("your distribution is broken");
         }
     }
 

libs/core/src/main/java/org/elasticsearch/core/Booleans.java

@@ -118,16 +118,10 @@ public final class Booleans {
         if (value == null) {
             return defaultValue;
         }
-        switch (value) {
+        return switch (value) {
-            case "false":
+            case "false", "0", "off", "no" -> false;
-            case "0":
+            default -> true;
-            case "off":
+        };
-            case "no":
-                return false;
-
-            default:
-                return true;
-        }
     }
 
     /**

libs/core/src/main/java/org/elasticsearch/core/TimeValue.java

@@ -318,24 +318,15 @@ public class TimeValue implements Comparable<TimeValue> {
         if (duration < 0) {
             return Long.toString(duration);
         }
-        switch (timeUnit) {
+        return switch (timeUnit) {
-            case NANOSECONDS:
+            case NANOSECONDS -> duration + "nanos";
-                return duration + "nanos";
+            case MICROSECONDS -> duration + "micros";
-            case MICROSECONDS:
+            case MILLISECONDS -> duration + "ms";
-                return duration + "micros";
+            case SECONDS -> duration + "s";
-            case MILLISECONDS:
+            case MINUTES -> duration + "m";
-                return duration + "ms";
+            case HOURS -> duration + "h";
-            case SECONDS:
+            case DAYS -> duration + "d";
-                return duration + "s";
+        };
-            case MINUTES:
-                return duration + "m";
-            case HOURS:
-                return duration + "h";
-            case DAYS:
-                return duration + "d";
-            default:
-                throw new IllegalArgumentException("unknown time unit: " + timeUnit.name());
-        }
     }
 
     public static TimeValue parseTimeValue(String sValue, String settingName) {

libs/dissect/src/main/java/org/elasticsearch/dissect/DissectMatch.java

@@ -60,22 +60,13 @@ final class DissectMatch {
             return;
         }
         switch (key.getModifier()) {
-            case NONE:
+            case NONE -> simpleResults.put(key.getName(), value);
-                simpleResults.put(key.getName(), value);
+            case APPEND -> appendResults.computeIfAbsent(key.getName(), k -> new AppendResult(appendSeparator))
-                break;
+                .addValue(value, implicitAppendOrder++);
-            case APPEND:
+            case APPEND_WITH_ORDER -> appendResults.computeIfAbsent(key.getName(), k -> new AppendResult(appendSeparator))
-                appendResults.computeIfAbsent(key.getName(), k -> new AppendResult(appendSeparator)).addValue(value, implicitAppendOrder++);
-                break;
-            case APPEND_WITH_ORDER:
-                appendResults.computeIfAbsent(key.getName(), k -> new AppendResult(appendSeparator))
                 .addValue(value, key.getAppendPosition());
-                break;
+            case FIELD_NAME -> referenceResults.computeIfAbsent(key.getName(), k -> new ReferenceResult()).setKey(value);
-            case FIELD_NAME:
+            case FIELD_VALUE -> referenceResults.computeIfAbsent(key.getName(), k -> new ReferenceResult()).setValue(value);
-                referenceResults.computeIfAbsent(key.getName(), k -> new ReferenceResult()).setKey(value);
-                break;
-            case FIELD_VALUE:
-                referenceResults.computeIfAbsent(key.getName(), k -> new ReferenceResult()).setValue(value);
-                break;
         }
     }
 

libs/geo/src/main/java/org/elasticsearch/geometry/utils/WellKnownText.java

@@ -506,17 +506,13 @@ public class WellKnownText {
     }
 
     private static String tokenString(StreamTokenizer stream) {
-        switch (stream.ttype) {
+        return switch (stream.ttype) {
-            case StreamTokenizer.TT_WORD:
+            case StreamTokenizer.TT_WORD -> stream.sval;
-                return stream.sval;
+            case StreamTokenizer.TT_EOF -> EOF;
-            case StreamTokenizer.TT_EOF:
+            case StreamTokenizer.TT_EOL -> EOL;
-                return EOF;
+            case StreamTokenizer.TT_NUMBER -> NUMBER;
-            case StreamTokenizer.TT_EOL:
+            default -> "'" + (char) stream.ttype + "'";
-                return EOL;
+        };
-            case StreamTokenizer.TT_NUMBER:
-                return NUMBER;
-        }
-        return "'" + (char) stream.ttype + "'";
     }
 
     private static boolean isNumberNext(StreamTokenizer stream) throws IOException {

libs/grok/src/main/java/org/elasticsearch/grok/GrokCaptureType.java

@@ -58,22 +58,15 @@ enum GrokCaptureType {
     abstract <T> T nativeExtracter(int[] backRefs, NativeExtracterMap<T> map);
 
     static GrokCaptureType fromString(String str) {
-        switch (str) {
+        return switch (str) {
-            case "string":
+            case "string" -> STRING;
-                return STRING;
+            case "int" -> INTEGER;
-            case "int":
+            case "long" -> LONG;
-                return INTEGER;
+            case "float" -> FLOAT;
-            case "long":
+            case "double" -> DOUBLE;
-                return LONG;
+            case "boolean" -> BOOLEAN;
-            case "float":
+            default -> STRING;
-                return FLOAT;
+        };
-            case "double":
-                return DOUBLE;
-            case "boolean":
-                return BOOLEAN;
-            default:
-                return STRING;
-        }
     }
 
     protected final GrokCaptureExtracter rawExtracter(int[] backRefs, Consumer<? super String> emit) {

libs/lz4/src/main/java/org/elasticsearch/lz4/LZ4SafeUtils.java

@@ -74,27 +74,15 @@ enum LZ4SafeUtils {
             int dec = 0;
             assert dOff >= matchOff && dOff - matchOff < 8;
             switch (dOff - matchOff) {
-                case 1:
+                case 1 -> matchOff -= 3;
-                    matchOff -= 3;
+                case 2 -> matchOff -= 2;
-                    break;
+                case 3 -> {
-                case 2:
-                    matchOff -= 2;
-                    break;
-                case 3:
                     matchOff -= 3;
                     dec = -1;
-                    break;
+                }
-                case 5:
+                case 5 -> dec = 1;
-                    dec = 1;
+                case 6 -> dec = 2;
-                    break;
+                case 7 -> dec = 3;
-                case 6:
-                    dec = 2;
-                    break;
-                case 7:
-                    dec = 3;
-                    break;
-                default:
-                    break;
             }
 
             copy4Bytes(dest, matchOff, dest, dOff);

libs/ssl-config/src/main/java/org/elasticsearch/common/ssl/DerParser.java

@@ -268,17 +268,15 @@ public final class DerParser {
             }
             StringBuilder sb = new StringBuilder(64);
             switch (value[0] / 40) {
-                case 0:
+                case 0 -> sb.append('0');
-                    sb.append('0');
+                case 1 -> {
-                    break;
-                case 1:
                     sb.append('1');
                     value[0] -= 40;
-                    break;
+                }
-                default:
+                default -> {
                     sb.append('2');
                     value[0] -= 80;
-                    break;
+                }
             }
             int oidPart = 0;
             for (int i = 0; i < length; i++) {

libs/ssl-config/src/main/java/org/elasticsearch/common/ssl/PemUtils.java

@@ -654,17 +654,14 @@ public final class PemUtils {
         DerParser.Asn1Object algSequence = parser.readAsn1Object();
         parser = algSequence.getParser();
         String oidString = parser.readAsn1Object().getOid();
-        switch (oidString) {
+        return switch (oidString) {
-            case "1.2.840.10040.4.1":
+            case "1.2.840.10040.4.1" -> "DSA";
-                return "DSA";
+            case "1.2.840.113549.1.1.1" -> "RSA";
-            case "1.2.840.113549.1.1.1":
+            case "1.2.840.10045.2.1" -> "EC";
-                return "RSA";
+            default -> throw new GeneralSecurityException(
-            case "1.2.840.10045.2.1":
-                return "EC";
-        }
-        throw new GeneralSecurityException(
                 "Error parsing key algorithm identifier. Algorithm with OID [" + oidString + "] is not supported"
             );
+        };
     }
 
     public static List<Certificate> readCertificates(Collection<Path> certPaths) throws CertificateException, IOException {
@@ -683,92 +680,55 @@ public final class PemUtils {
     }
 
     private static String getAlgorithmNameFromOid(String oidString) throws GeneralSecurityException {
-        switch (oidString) {
+        return switch (oidString) {
-            case "1.2.840.10040.4.1":
+            case "1.2.840.10040.4.1" -> "DSA";
-                return "DSA";
+            case "1.2.840.113549.1.1.1" -> "RSA";
-            case "1.2.840.113549.1.1.1":
+            case "1.2.840.10045.2.1" -> "EC";
-                return "RSA";
+            case "1.3.14.3.2.7" -> "DES-CBC";
-            case "1.2.840.10045.2.1":
+            case "2.16.840.1.101.3.4.1.1" -> "AES-128_ECB";
-                return "EC";
+            case "2.16.840.1.101.3.4.1.2" -> "AES-128_CBC";
-            case "1.3.14.3.2.7":
+            case "2.16.840.1.101.3.4.1.3" -> "AES-128_OFB";
-                return "DES-CBC";
+            case "2.16.840.1.101.3.4.1.4" -> "AES-128_CFB";
-            case "2.16.840.1.101.3.4.1.1":
+            case "2.16.840.1.101.3.4.1.6" -> "AES-128_GCM";
-                return "AES-128_ECB";
+            case "2.16.840.1.101.3.4.1.21" -> "AES-192_ECB";
-            case "2.16.840.1.101.3.4.1.2":
+            case "2.16.840.1.101.3.4.1.22" -> "AES-192_CBC";
-                return "AES-128_CBC";
+            case "2.16.840.1.101.3.4.1.23" -> "AES-192_OFB";
-            case "2.16.840.1.101.3.4.1.3":
+            case "2.16.840.1.101.3.4.1.24" -> "AES-192_CFB";
-                return "AES-128_OFB";
+            case "2.16.840.1.101.3.4.1.26" -> "AES-192_GCM";
-            case "2.16.840.1.101.3.4.1.4":
+            case "2.16.840.1.101.3.4.1.41" -> "AES-256_ECB";
-                return "AES-128_CFB";
+            case "2.16.840.1.101.3.4.1.42" -> "AES-256_CBC";
-            case "2.16.840.1.101.3.4.1.6":
+            case "2.16.840.1.101.3.4.1.43" -> "AES-256_OFB";
-                return "AES-128_GCM";
+            case "2.16.840.1.101.3.4.1.44" -> "AES-256_CFB";
-            case "2.16.840.1.101.3.4.1.21":
+            case "2.16.840.1.101.3.4.1.46" -> "AES-256_GCM";
-                return "AES-192_ECB";
+            case "2.16.840.1.101.3.4.1.5" -> "AESWrap-128";
-            case "2.16.840.1.101.3.4.1.22":
+            case "2.16.840.1.101.3.4.1.25" -> "AESWrap-192";
-                return "AES-192_CBC";
+            case "2.16.840.1.101.3.4.1.45" -> "AESWrap-256";
-            case "2.16.840.1.101.3.4.1.23":
+            default -> null;
-                return "AES-192_OFB";
+        };
-            case "2.16.840.1.101.3.4.1.24":
-                return "AES-192_CFB";
-            case "2.16.840.1.101.3.4.1.26":
-                return "AES-192_GCM";
-            case "2.16.840.1.101.3.4.1.41":
-                return "AES-256_ECB";
-            case "2.16.840.1.101.3.4.1.42":
-                return "AES-256_CBC";
-            case "2.16.840.1.101.3.4.1.43":
-                return "AES-256_OFB";
-            case "2.16.840.1.101.3.4.1.44":
-                return "AES-256_CFB";
-            case "2.16.840.1.101.3.4.1.46":
-                return "AES-256_GCM";
-            case "2.16.840.1.101.3.4.1.5":
-                return "AESWrap-128";
-            case "2.16.840.1.101.3.4.1.25":
-                return "AESWrap-192";
-            case "2.16.840.1.101.3.4.1.45":
-                return "AESWrap-256";
-        }
-        return null;
     }
 
     private static String getEcCurveNameFromOid(String oidString) throws GeneralSecurityException {
-        switch (oidString) {
+        return switch (oidString) {
             // see https://tools.ietf.org/html/rfc5480#section-2.1.1.1
-            case "1.2.840.10045.3.1":
+            case "1.2.840.10045.3.1" -> "secp192r1";
-                return "secp192r1";
+            case "1.3.132.0.1" -> "sect163k1";
-            case "1.3.132.0.1":
+            case "1.3.132.0.15" -> "sect163r2";
-                return "sect163k1";
+            case "1.3.132.0.33" -> "secp224r1";
-            case "1.3.132.0.15":
+            case "1.3.132.0.26" -> "sect233k1";
-                return "sect163r2";
+            case "1.3.132.0.27" -> "sect233r1";
-            case "1.3.132.0.33":
+            case "1.2.840.10045.3.1.7" -> "secp256r1";
-                return "secp224r1";
+            case "1.3.132.0.16" -> "sect283k1";
-            case "1.3.132.0.26":
+            case "1.3.132.0.17" -> "sect283r1";
-                return "sect233k1";
+            case "1.3.132.0.34" -> "secp384r1";
-            case "1.3.132.0.27":
+            case "1.3.132.0.36" -> "sect409k1";
-                return "sect233r1";
+            case "1.3.132.0.37" -> "sect409r1";
-            case "1.2.840.10045.3.1.7":
+            case "1.3.132.0.35" -> "secp521r1";
-                return "secp256r1";
+            case "1.3.132.0.38" -> "sect571k1";
-            case "1.3.132.0.16":
+            case "1.3.132.0.39" -> "sect571r1";
-                return "sect283k1";
+            default -> throw new GeneralSecurityException(
-            case "1.3.132.0.17":
-                return "sect283r1";
-            case "1.3.132.0.34":
-                return "secp384r1";
-            case "1.3.132.0.36":
-                return "sect409k1";
-            case "1.3.132.0.37":
-                return "sect409r1";
-            case "1.3.132.0.35":
-                return "secp521r1";
-            case "1.3.132.0.38":
-                return "sect571k1";
-            case "1.3.132.0.39":
-                return "sect571r1";
-        }
-        throw new GeneralSecurityException(
                 "Error parsing EC named curve identifier. Named curve with OID: " + oidString + " is not supported"
             );
+        };
     }
 
 }

libs/ssl-config/src/test/java/org/elasticsearch/common/ssl/SslConfigurationTests.java

@@ -91,10 +91,13 @@ public class SslConfigurationTests extends ESTestCase {
                 orig.getCipherSuites(),
                 orig.getSupportedProtocols()
             ),
-            orig -> {
+            this::mutateSslConfiguration
-                switch (randomIntBetween(1, 4)) {
+        );
-                    case 1:
+    }
-                        return new SslConfiguration(
+
+    private SslConfiguration mutateSslConfiguration(SslConfiguration orig) {
+        return switch (randomIntBetween(1, 4)) {
+            case 1 -> new SslConfiguration(
                 true,
                 orig.getTrustConfig(),
                 orig.getKeyConfig(),
@@ -103,8 +106,7 @@ public class SslConfigurationTests extends ESTestCase {
                 orig.getCipherSuites(),
                 orig.getSupportedProtocols()
             );
-                    case 2:
+            case 2 -> new SslConfiguration(
-                        return new SslConfiguration(
                 true,
                 orig.getTrustConfig(),
                 orig.getKeyConfig(),
@@ -113,8 +115,7 @@ public class SslConfigurationTests extends ESTestCase {
                 orig.getCipherSuites(),
                 orig.getSupportedProtocols()
             );
-                    case 3:
+            case 3 -> new SslConfiguration(
-                        return new SslConfiguration(
                 true,
                 orig.getTrustConfig(),
                 orig.getKeyConfig(),
@@ -123,9 +124,7 @@ public class SslConfigurationTests extends ESTestCase {
                 DEFAULT_CIPHERS,
                 orig.getSupportedProtocols()
             );
-                    case 4:
+            default -> new SslConfiguration(
-                    default:
-                        return new SslConfiguration(
                 true,
                 orig.getTrustConfig(),
                 orig.getKeyConfig(),
@@ -134,9 +133,7 @@ public class SslConfigurationTests extends ESTestCase {
                 orig.getCipherSuites(),
                 Arrays.asList(VALID_PROTOCOLS)
             );
-                }
+        };
-            }
-        );
     }
 
     public void testDependentFiles() {

libs/x-content/src/main/java/org/elasticsearch/xcontent/ObjectParser.java

@@ -121,26 +121,13 @@ public final class ObjectParser<Value, Context> extends AbstractObjectParser<Val
         return (objectParser, field, location, parser, value, context) -> {
             XContentParser.Token t = parser.currentToken();
             switch (t) {
-                case VALUE_STRING:
+                case VALUE_STRING -> consumer.accept(value, field, parser.text());
-                    consumer.accept(value, field, parser.text());
+                case VALUE_NUMBER -> consumer.accept(value, field, parser.numberValue());
-                    break;
+                case VALUE_BOOLEAN -> consumer.accept(value, field, parser.booleanValue());
-                case VALUE_NUMBER:
+                case VALUE_NULL -> consumer.accept(value, field, null);
-                    consumer.accept(value, field, parser.numberValue());
+                case START_OBJECT -> consumer.accept(value, field, parser.map());
-                    break;
+                case START_ARRAY -> consumer.accept(value, field, parser.list());
-                case VALUE_BOOLEAN:
+                default -> throw new XContentParseException(
-                    consumer.accept(value, field, parser.booleanValue());
-                    break;
-                case VALUE_NULL:
-                    consumer.accept(value, field, null);
-                    break;
-                case START_OBJECT:
-                    consumer.accept(value, field, parser.map());
-                    break;
-                case START_ARRAY:
-                    consumer.accept(value, field, parser.list());
-                    break;
-                default:
-                    throw new XContentParseException(
                     parser.getTokenLocation(),
                     "[" + objectParser.name + "] cannot parse field [" + field + "] with value type [" + t + "]"
                 );
@@ -642,7 +629,7 @@ public final class ObjectParser<Value, Context> extends AbstractObjectParser<Val
     private void parseSub(XContentParser parser, FieldParser fieldParser, String currentFieldName, Value value, Context context) {
         final XContentParser.Token token = parser.currentToken();
         switch (token) {
-            case START_OBJECT:
+            case START_OBJECT -> {
                 parseValue(parser, fieldParser, currentFieldName, value, context);
                 /*
                  * Well behaving parsers should consume the entire object but
@@ -655,8 +642,8 @@ public final class ObjectParser<Value, Context> extends AbstractObjectParser<Val
                 if (parser.currentToken() != XContentParser.Token.END_OBJECT) {
                     throwMustEndOn(currentFieldName, XContentParser.Token.END_OBJECT);
                 }
-                break;
+            }
-            case START_ARRAY:
+            case START_ARRAY -> {
                 parseArray(parser, fieldParser, currentFieldName, value, context);
                 /*
                  * Well behaving parsers should consume the entire array but
@@ -669,17 +656,15 @@ public final class ObjectParser<Value, Context> extends AbstractObjectParser<Val
                 if (parser.currentToken() != XContentParser.Token.END_ARRAY) {
                     throwMustEndOn(currentFieldName, XContentParser.Token.END_ARRAY);
                 }
-                break;
+            }
-            case END_OBJECT:
+            case END_OBJECT, END_ARRAY, FIELD_NAME -> throw throwUnexpectedToken(parser, token);
-            case END_ARRAY:
+            case VALUE_STRING, VALUE_NUMBER, VALUE_BOOLEAN, VALUE_EMBEDDED_OBJECT, VALUE_NULL -> parseValue(
-            case FIELD_NAME:
+                parser,
-                throw throwUnexpectedToken(parser, token);
+                fieldParser,
-            case VALUE_STRING:
+                currentFieldName,
-            case VALUE_NUMBER:
+                value,
-            case VALUE_BOOLEAN:
+                context
-            case VALUE_EMBEDDED_OBJECT:
+            );
-            case VALUE_NULL:
-                parseValue(parser, fieldParser, currentFieldName, value, context);
         }
     }
 

libs/x-content/src/main/java/org/elasticsearch/xcontent/XContentGenerator.java

@@ -137,18 +137,10 @@ public interface XContentGenerator extends Closeable, Flushable {
                 break;
             case VALUE_NUMBER:
                 switch (parser.numberType()) {
-                    case INT:
+                    case INT -> writeNumber(parser.intValue());
-                        writeNumber(parser.intValue());
+                    case LONG -> writeNumber(parser.longValue());
-                        break;
+                    case FLOAT -> writeNumber(parser.floatValue());
-                    case LONG:
+                    case DOUBLE -> writeNumber(parser.doubleValue());
-                        writeNumber(parser.longValue());
-                        break;
-                    case FLOAT:
-                        writeNumber(parser.floatValue());
-                        break;
-                    case DOUBLE:
-                        writeNumber(parser.doubleValue());
-                        break;
                 }
                 break;
             case VALUE_BOOLEAN:

libs/x-content/src/main/java/org/elasticsearch/xcontent/json/JsonXContentGenerator.java

@@ -413,21 +413,21 @@ public class JsonXContentGenerator implements XContentGenerator {
         }
 
         switch (token) {
-            case START_ARRAY:
+            case START_ARRAY -> {
                 destination.writeStartArray();
                 while (parser.nextToken() != XContentParser.Token.END_ARRAY) {
                     copyCurrentStructure(destination, parser);
                 }
                 destination.writeEndArray();
-                break;
+            }
-            case START_OBJECT:
+            case START_OBJECT -> {
                 destination.writeStartObject();
                 while (parser.nextToken() != XContentParser.Token.END_OBJECT) {
                     copyCurrentStructure(destination, parser);
                 }
                 destination.writeEndObject();
-                break;
+            }
-            default: // others are simple:
+            default -> // others are simple:
                 destination.copyCurrentEvent(parser);
         }
     }

libs/x-content/src/main/java/org/elasticsearch/xcontent/json/JsonXContentParser.java

@@ -189,21 +189,14 @@ public class JsonXContentParser extends AbstractXContentParser {
     }
 
     private NumberType convertNumberType(JsonParser.NumberType numberType) {
-        switch (numberType) {
+        return switch (numberType) {
-            case INT:
+            case INT -> NumberType.INT;
-                return NumberType.INT;
+            case BIG_INTEGER -> NumberType.BIG_INTEGER;
-            case BIG_INTEGER:
+            case LONG -> NumberType.LONG;
-                return NumberType.BIG_INTEGER;
+            case FLOAT -> NumberType.FLOAT;
-            case LONG:
+            case DOUBLE -> NumberType.DOUBLE;
-                return NumberType.LONG;
+            case BIG_DECIMAL -> NumberType.BIG_DECIMAL;
-            case FLOAT:
+        };
-                return NumberType.FLOAT;
-            case DOUBLE:
-                return NumberType.DOUBLE;
-            case BIG_DECIMAL:
-                return NumberType.BIG_DECIMAL;
-        }
-        throw new IllegalStateException("No matching token for number_type [" + numberType + "]");
     }
 
     private Token convertToken(JsonToken token) {

libs/x-content/src/main/java/org/elasticsearch/xcontent/support/AbstractXContentParser.java

@@ -81,14 +81,11 @@ public abstract class AbstractXContentParser implements XContentParser {
 
     @Override
     public boolean isBooleanValue() throws IOException {
-        switch (currentToken()) {
+        return switch (currentToken()) {
-            case VALUE_BOOLEAN:
+            case VALUE_BOOLEAN -> true;
-                return true;
+            case VALUE_STRING -> Booleans.isBoolean(textCharacters(), textOffset(), textLength());
-            case VALUE_STRING:
+            default -> false;
-                return Booleans.isBoolean(textCharacters(), textOffset(), textLength());
+        };
-            default:
-                return false;
-        }
     }
 
     @Override

libs/x-content/src/test/java/org/elasticsearch/xcontent/MapXContentParserTests.java

@@ -138,10 +138,8 @@ public class MapXContentParserTests extends ESTestCase {
                                 assertEquals(parser.textOrNull(), mapParser.textOrNull());
                             }
                             switch (token) {
-                                case VALUE_STRING:
+                                case VALUE_STRING -> assertEquals(parser.text(), mapParser.text());
-                                    assertEquals(parser.text(), mapParser.text());
+                                case VALUE_NUMBER -> {
-                                    break;
-                                case VALUE_NUMBER:
                                     assertEquals(parser.numberType(), mapParser.numberType());
                                     assertEquals(parser.numberValue(), mapParser.numberValue());
                                     if (parser.numberType() == XContentParser.NumberType.LONG
@@ -156,16 +154,10 @@ public class MapXContentParserTests extends ESTestCase {
                                     } else {
                                         assertEquals(parser.doubleValue(), mapParser.doubleValue(), 0.000001);
                                     }
-                                    break;
+                                }
-                                case VALUE_BOOLEAN:
+                                case VALUE_BOOLEAN -> assertEquals(parser.booleanValue(), mapParser.booleanValue());
-                                    assertEquals(parser.booleanValue(), mapParser.booleanValue());
+                                case VALUE_EMBEDDED_OBJECT -> assertArrayEquals(parser.binaryValue(), mapParser.binaryValue());
-                                    break;
+                                case VALUE_NULL -> assertNull(mapParser.textOrNull());
-                                case VALUE_EMBEDDED_OBJECT:
-                                    assertArrayEquals(parser.binaryValue(), mapParser.binaryValue());
-                                    break;
-                                case VALUE_NULL:
-                                    assertNull(mapParser.textOrNull());
-                                    break;
                             }
                             assertEquals(parser.currentName(), mapParser.currentName());
                             assertEquals(parser.isClosed(), mapParser.isClosed());

libs/x-content/src/test/java/org/elasticsearch/xcontent/XContentParserTests.java

@@ -69,20 +69,9 @@ public class XContentParserTests extends ESTestCase {
             assertEquals(value, number.floatValue(), 0.0f);
 
             switch (xContentType) {
-                case VND_CBOR:
+                case VND_CBOR, VND_SMILE, CBOR, SMILE -> assertThat(number, instanceOf(Float.class));
-                case VND_SMILE:
+                case VND_JSON, VND_YAML, JSON, YAML -> assertThat(number, instanceOf(Double.class));
-                case CBOR:
+                default -> throw new AssertionError("unexpected x-content type [" + xContentType + "]");
-                case SMILE:
-                    assertThat(number, instanceOf(Float.class));
-                    break;
-                case VND_JSON:
-                case VND_YAML:
-                case JSON:
-                case YAML:
-                    assertThat(number, instanceOf(Double.class));
-                    break;
-                default:
-                    throw new AssertionError("unexpected x-content type [" + xContentType + "]");
             }
         }
     }

libs/x-content/src/test/java/org/elasticsearch/xcontent/support/filtering/AbstractXContentFilteringTestCase.java

@@ -122,18 +122,12 @@ public abstract class AbstractXContentFilteringTestCase extends AbstractFilterin
                 }
                 assertThat(token1, equalTo(token2));
                 switch (token1) {
-                    case FIELD_NAME:
+                    case FIELD_NAME -> assertThat(jsonParser.currentName(), equalTo(testParser.currentName()));
-                        assertThat(jsonParser.currentName(), equalTo(testParser.currentName()));
+                    case VALUE_STRING -> assertThat(jsonParser.text(), equalTo(testParser.text()));
-                        break;
+                    case VALUE_NUMBER -> {
-                    case VALUE_STRING:
-                        assertThat(jsonParser.text(), equalTo(testParser.text()));
-                        break;
-                    case VALUE_NUMBER:
                         assertThat(jsonParser.numberType(), equalTo(testParser.numberType()));
                         assertThat(jsonParser.numberValue(), equalTo(testParser.numberValue()));
-                        break;
+                    }
-                    default:
-                        break;
                 }
             }
         } catch (Exception e) {

modules/aggs-matrix-stats/src/main/java/org/elasticsearch/search/aggregations/matrix/stats/InternalMatrixStats.java

@@ -203,24 +203,16 @@ public class InternalMatrixStats extends InternalAggregation implements MatrixSt
             if (results == null) {
                 return emptyMap();
             }
-            switch (element) {
+            return switch (element) {
-                case "counts":
+                case "counts" -> results.getFieldCounts();
-                    return results.getFieldCounts();
+                case "means" -> results.getMeans();
-                case "means":
+                case "variances" -> results.getVariances();
-                    return results.getMeans();
+                case "skewness" -> results.getSkewness();
-                case "variances":
+                case "kurtosis" -> results.getKurtosis();
-                    return results.getVariances();
+                case "covariance" -> results.getCovariances();
-                case "skewness":
+                case "correlation" -> results.getCorrelations();
-                    return results.getSkewness();
+                default -> throw new IllegalArgumentException("Found unknown path element [" + element + "] in [" + getName() + "]");
-                case "kurtosis":
+            };
-                    return results.getKurtosis();
-                case "covariance":
-                    return results.getCovariances();
-                case "correlation":
-                    return results.getCorrelations();
-                default:
-                    throw new IllegalArgumentException("Found unknown path element [" + element + "] in [" + getName() + "]");
-            }
         } else {
             throw new IllegalArgumentException("path not supported for [" + getName() + "]: " + path);
         }

modules/analysis-common/src/main/java/org/elasticsearch/analysis/common/CharGroupTokenizerFactory.java

@@ -47,23 +47,12 @@ public class CharGroupTokenizerFactory extends AbstractTokenizerFactory {
                 tokenizeOnChars.add((int) parseEscapedChar(c));
             } else {
                 switch (c) {
-                    case "letter":
+                    case "letter" -> tokenizeOnLetter = true;
-                        tokenizeOnLetter = true;
+                    case "digit" -> tokenizeOnDigit = true;
-                        break;
+                    case "whitespace" -> tokenizeOnSpace = true;
-                    case "digit":
+                    case "punctuation" -> tokenizeOnPunctuation = true;
-                        tokenizeOnDigit = true;
+                    case "symbol" -> tokenizeOnSymbol = true;
-                        break;
+                    default -> throw new RuntimeException("Invalid escaped char in [" + c + "]");
-                    case "whitespace":
-                        tokenizeOnSpace = true;
-                        break;
-                    case "punctuation":
-                        tokenizeOnPunctuation = true;
-                        break;
-                    case "symbol":
-                        tokenizeOnSymbol = true;
-                        break;
-                    default:
-                        throw new RuntimeException("Invalid escaped char in [" + c + "]");
                 }
             }
         }

modules/analysis-common/src/main/java/org/elasticsearch/analysis/common/EdgeNGramTokenFilterFactory.java

@@ -38,14 +38,11 @@ public class EdgeNGramTokenFilterFactory extends AbstractTokenFilterFactory {
     }
 
     static int parseSide(String side) {
-        switch (side) {
+        return switch (side) {
-            case "front":
+            case "front" -> SIDE_FRONT;
-                return SIDE_FRONT;
+            case "back" -> SIDE_BACK;
-            case "back":
+            default -> throw new IllegalArgumentException("invalid side: " + side);
-                return SIDE_BACK;
+        };
-            default:
-                throw new IllegalArgumentException("invalid side: " + side);
-        }
     }
 
     @Override

modules/analysis-common/src/main/java/org/elasticsearch/analysis/common/MappingCharFilterFactory.java

@@ -75,29 +75,17 @@ public class MappingCharFilterFactory extends AbstractCharFilterFactory implemen
                 if (readPos >= len) throw new RuntimeException("Invalid escaped char in [" + s + "]");
                 c = s.charAt(readPos++);
                 switch (c) {
-                    case '\\':
+                    case '\\' -> c = '\\';
-                        c = '\\';
+                    case 'n' -> c = '\n';
-                        break;
+                    case 't' -> c = '\t';
-                    case 'n':
+                    case 'r' -> c = '\r';
-                        c = '\n';
+                    case 'b' -> c = '\b';
-                        break;
+                    case 'f' -> c = '\f';
-                    case 't':
+                    case 'u' -> {
-                        c = '\t';
-                        break;
-                    case 'r':
-                        c = '\r';
-                        break;
-                    case 'b':
-                        c = '\b';
-                        break;
-                    case 'f':
-                        c = '\f';
-                        break;
-                    case 'u':
                         if (readPos + 3 >= len) throw new RuntimeException("Invalid escaped char in [" + s + "]");
                         c = (char) Integer.parseInt(s.substring(readPos, readPos + 4), 16);
                         readPos += 4;
-                        break;
+                    }
                 }
             }
             out[writePos++] = c;

modules/analysis-common/src/main/java/org/elasticsearch/analysis/common/WordDelimiterTokenFilterFactory.java

@@ -152,29 +152,17 @@ public class WordDelimiterTokenFilterFactory extends AbstractTokenFilterFactory
                 if (readPos >= len) throw new RuntimeException("Invalid escaped char in [" + s + "]");
                 c = s.charAt(readPos++);
                 switch (c) {
-                    case '\\':
+                    case '\\' -> c = '\\';
-                        c = '\\';
+                    case 'n' -> c = '\n';
-                        break;
+                    case 't' -> c = '\t';
-                    case 'n':
+                    case 'r' -> c = '\r';
-                        c = '\n';
+                    case 'b' -> c = '\b';
-                        break;
+                    case 'f' -> c = '\f';
-                    case 't':
+                    case 'u' -> {
-                        c = '\t';
-                        break;
-                    case 'r':
-                        c = '\r';
-                        break;
-                    case 'b':
-                        c = '\b';
-                        break;
-                    case 'f':
-                        c = '\f';
-                        break;
-                    case 'u':
                         if (readPos + 3 >= len) throw new RuntimeException("Invalid escaped char in [" + s + "]");
                         c = (char) Integer.parseInt(s.substring(readPos, readPos + 4), 16);
                         readPos += 4;
-                        break;
+                    }
                 }
             }
             out[writePos++] = c;

modules/ingest-common/src/main/java/org/elasticsearch/ingest/common/CommunityIdProcessor.java

@@ -226,25 +226,21 @@ public final class CommunityIdProcessor extends AbstractProcessor {
         flow.protocol = Transport.fromObject(protocol);
 
         switch (flow.protocol) {
-            case Tcp:
+            case Tcp, Udp, Sctp -> {
-            case Udp:
-            case Sctp:
                 flow.sourcePort = parseIntFromObjectOrString(sourcePort.get(), "source port");
                 if (flow.sourcePort < 1 || flow.sourcePort > 65535) {
                     throw new IllegalArgumentException("invalid source port [" + sourcePort.get() + "]");
                 }
-
                 flow.destinationPort = parseIntFromObjectOrString(destinationPort.get(), "destination port");
                 if (flow.destinationPort < 1 || flow.destinationPort > 65535) {
                     throw new IllegalArgumentException("invalid destination port [" + destinationPort.get() + "]");
                 }
-                break;
+            }
-            case Icmp:
+            case Icmp, IcmpIpV6 -> {
-            case IcmpIpV6:
                 // tolerate missing or invalid ICMP types and codes
                 flow.icmpType = parseIntFromObjectOrString(icmpType, "icmp type");
                 flow.icmpCode = parseIntFromObjectOrString(icmpCode, "icmp code");
-                break;
+            }
         }
 
         return flow;
@@ -441,30 +437,19 @@ public final class CommunityIdProcessor extends AbstractProcessor {
         }
 
         public static Transport fromNumber(int transportNumber) {
-            switch (transportNumber) {
+            return switch (transportNumber) {
-                case 1:
+                case 1 -> Icmp;
-                    return Icmp;
+                case 2 -> Igmp;
-                case 2:
+                case 6 -> Tcp;
-                    return Igmp;
+                case 17 -> Udp;
-                case 6:
+                case 47 -> Gre;
-                    return Tcp;
+                case 58 -> IcmpIpV6;
-                case 17:
+                case 88 -> Eigrp;
-                    return Udp;
+                case 89 -> Ospf;
-                case 47:
+                case 103 -> Pim;
-                    return Gre;
+                case 132 -> Sctp;
-                case 58:
+                default -> throw new IllegalArgumentException("unknown transport protocol number [" + transportNumber + "]");
-                    return IcmpIpV6;
+            };
-                case 88:
-                    return Eigrp;
-                case 89:
-                    return Ospf;
-                case 103:
-                    return Pim;
-                case 132:
-                    return Sctp;
-                default:
-                    throw new IllegalArgumentException("unknown transport protocol number [" + transportNumber + "]");
-            }
         }
 
         public static Transport fromObject(Object o) {
@@ -557,55 +542,33 @@ public final class CommunityIdProcessor extends AbstractProcessor {
         }
 
         public static IcmpType fromNumber(int type) {
-            switch (type) {
+            return switch (type) {
-                case 0:
+                case 0 -> EchoReply;
-                    return EchoReply;
+                case 8 -> EchoRequest;
-                case 8:
+                case 9 -> RouterAdvertisement;
-                    return EchoRequest;
+                case 10 -> RouterSolicitation;
-                case 9:
+                case 13 -> TimestampRequest;
-                    return RouterAdvertisement;
+                case 14 -> TimestampReply;
-                case 10:
+                case 15 -> InfoRequest;
-                    return RouterSolicitation;
+                case 16 -> InfoReply;
-                case 13:
+                case 17 -> AddressMaskRequest;
-                    return TimestampRequest;
+                case 18 -> AddressMaskReply;
-                case 14:
+                case 128 -> V6EchoRequest;
-                    return TimestampReply;
+                case 129 -> V6EchoReply;
-                case 15:
+                case 133 -> V6RouterSolicitation;
-                    return InfoRequest;
+                case 134 -> V6RouterAdvertisement;
-                case 16:
+                case 135 -> V6NeighborSolicitation;
-                    return InfoReply;
+                case 136 -> V6NeighborAdvertisement;
-                case 17:
+                case 130 -> V6MLDv1MulticastListenerQueryMessage;
-                    return AddressMaskRequest;
+                case 131 -> V6MLDv1MulticastListenerReportMessage;
-                case 18:
+                case 139 -> V6WhoAreYouRequest;
-                    return AddressMaskReply;
+                case 140 -> V6WhoAreYouReply;
-                case 128:
+                case 144 -> V6HomeAddressDiscoveryRequest;
-                    return V6EchoRequest;
+                case 145 -> V6HomeAddressDiscoveryResponse;
-                case 129:
+                default ->
-                    return V6EchoReply;
-                case 133:
-                    return V6RouterSolicitation;
-                case 134:
-                    return V6RouterAdvertisement;
-                case 135:
-                    return V6NeighborSolicitation;
-                case 136:
-                    return V6NeighborAdvertisement;
-                case 130:
-                    return V6MLDv1MulticastListenerQueryMessage;
-                case 131:
-                    return V6MLDv1MulticastListenerReportMessage;
-                case 139:
-                    return V6WhoAreYouRequest;
-                case 140:
-                    return V6WhoAreYouReply;
-                case 144:
-                    return V6HomeAddressDiscoveryRequest;
-                case 145:
-                    return V6HomeAddressDiscoveryResponse;
-                default:
                     // don't fail if the type is unknown
-                    return EchoReply;
+                    EchoReply;
-            }
+            };
         }
 
         public static Integer codeEquivalent(int icmpType, boolean isIpV6) {

modules/ingest-common/src/main/java/org/elasticsearch/ingest/common/CsvParser.java

@@ -75,14 +75,9 @@ final class CsvParser {
 
         // we've reached end of string, we need to handle last field
         switch (state) {
-            case UNQUOTED:
+            case UNQUOTED -> setField(length);
-                setField(length);
+            case QUOTED_END -> setField(length - 1);
-                break;
+            case QUOTED -> throw new IllegalArgumentException("Unmatched quote");
-            case QUOTED_END:
-                setField(length - 1);
-                break;
-            case QUOTED:
-                throw new IllegalArgumentException("Unmatched quote");
         }
     }
 

modules/ingest-common/src/main/java/org/elasticsearch/ingest/common/DateFormat.java

@@ -118,17 +118,12 @@ enum DateFormat {
     abstract Function<String, ZonedDateTime> getFunction(String format, ZoneId timezone, Locale locale);
 
     static DateFormat fromString(String format) {
-        switch (format) {
+        return switch (format) {
-            case "ISO8601":
+            case "ISO8601" -> Iso8601;
-                return Iso8601;
+            case "UNIX" -> Unix;
-            case "UNIX":
+            case "UNIX_MS" -> UnixMs;
-                return Unix;
+            case "TAI64N" -> Tai64n;
-            case "UNIX_MS":
+            default -> Java;
-                return UnixMs;
+        };
-            case "TAI64N":
-                return Tai64n;
-            default:
-                return Java;
-        }
     }
 }

modules/ingest-common/src/main/java/org/elasticsearch/ingest/common/NetworkDirectionProcessor.java

@@ -165,29 +165,18 @@ public class NetworkDirectionProcessor extends AbstractProcessor {
 
     private boolean inNetwork(String ip, String network) {
         InetAddress address = InetAddresses.forString(ip);
-        switch (network) {
+        return switch (network) {
-            case LOOPBACK_NAMED_NETWORK:
+            case LOOPBACK_NAMED_NETWORK -> isLoopback(address);
-                return isLoopback(address);
+            case GLOBAL_UNICAST_NAMED_NETWORK, UNICAST_NAMED_NETWORK -> isUnicast(address);
-            case GLOBAL_UNICAST_NAMED_NETWORK:
+            case LINK_LOCAL_UNICAST_NAMED_NETWORK -> isLinkLocalUnicast(address);
-            case UNICAST_NAMED_NETWORK:
+            case INTERFACE_LOCAL_NAMED_NETWORK -> isInterfaceLocalMulticast(address);
-                return isUnicast(address);
+            case LINK_LOCAL_MULTICAST_NAMED_NETWORK -> isLinkLocalMulticast(address);
-            case LINK_LOCAL_UNICAST_NAMED_NETWORK:
+            case MULTICAST_NAMED_NETWORK -> isMulticast(address);
-                return isLinkLocalUnicast(address);
+            case UNSPECIFIED_NAMED_NETWORK -> isUnspecified(address);
-            case INTERFACE_LOCAL_NAMED_NETWORK:
+            case PRIVATE_NAMED_NETWORK -> isPrivate(ip);
-                return isInterfaceLocalMulticast(address);
+            case PUBLIC_NAMED_NETWORK -> isPublic(ip);
-            case LINK_LOCAL_MULTICAST_NAMED_NETWORK:
+            default -> CIDRUtils.isInRange(ip, network);
-                return isLinkLocalMulticast(address);
+        };
-            case MULTICAST_NAMED_NETWORK:
-                return isMulticast(address);
-            case UNSPECIFIED_NAMED_NETWORK:
-                return isUnspecified(address);
-            case PRIVATE_NAMED_NETWORK:
-                return isPrivate(ip);
-            case PUBLIC_NAMED_NETWORK:
-                return isPublic(ip);
-            default:
-                return CIDRUtils.isInRange(ip, network);
-        }
     }
 
     private boolean isLoopback(InetAddress ip) {

modules/ingest-common/src/test/java/org/elasticsearch/ingest/common/ConvertProcessorTests.java

@@ -383,23 +383,22 @@ public class ConvertProcessorTests extends ESTestCase {
         Object fieldValue;
         String expectedFieldValue;
         switch (randomIntBetween(0, 2)) {
-            case 0:
+            case 0 -> {
                 float randomFloat = randomFloat();
                 fieldValue = randomFloat;
                 expectedFieldValue = Float.toString(randomFloat);
-                break;
+            }
-            case 1:
+            case 1 -> {
                 int randomInt = randomInt();
                 fieldValue = randomInt;
                 expectedFieldValue = Integer.toString(randomInt);
-                break;
+            }
-            case 2:
+            case 2 -> {
                 boolean randomBoolean = randomBoolean();
                 fieldValue = randomBoolean;
                 expectedFieldValue = Boolean.toString(randomBoolean);
-                break;
+            }
-            default:
+            default -> throw new UnsupportedOperationException();
-                throw new UnsupportedOperationException();
         }
         String fieldName = RandomDocumentPicks.addRandomField(random(), ingestDocument, fieldValue);
 
@@ -417,33 +416,32 @@ public class ConvertProcessorTests extends ESTestCase {
             Object randomValue;
             String randomValueString;
             switch (randomIntBetween(0, 2)) {
-                case 0:
+                case 0 -> {
                     float randomFloat = randomFloat();
                     randomValue = randomFloat;
                     randomValueString = Float.toString(randomFloat);
-                    break;
+                }
-                case 1:
+                case 1 -> {
                     int randomInt = randomInt();
                     randomValue = randomInt;
                     randomValueString = Integer.toString(randomInt);
-                    break;
+                }
-                case 2:
+                case 2 -> {
                     boolean randomBoolean = randomBoolean();
                     randomValue = randomBoolean;
                     randomValueString = Boolean.toString(randomBoolean);
-                    break;
+                }
-                case 3:
+                case 3 -> {
                     long randomLong = randomLong();
                     randomValue = randomLong;
                     randomValueString = Long.toString(randomLong);
-                    break;
+                }
-                case 4:
+                case 4 -> {
                     double randomDouble = randomDouble();
                     randomValue = randomDouble;
                     randomValueString = Double.toString(randomDouble);
-                    break;
+                }
-                default:
+                default -> throw new UnsupportedOperationException();
-                    throw new UnsupportedOperationException();
             }
             fieldValue.add(randomValue);
             expectedList.add(randomValueString);
@@ -501,20 +499,19 @@ public class ConvertProcessorTests extends ESTestCase {
     public void testAutoConvertNotString() throws Exception {
         Object randomValue;
         switch (randomIntBetween(0, 2)) {
-            case 0:
+            case 0 -> {
                 float randomFloat = randomFloat();
                 randomValue = randomFloat;
-                break;
+            }
-            case 1:
+            case 1 -> {
                 int randomInt = randomInt();
                 randomValue = randomInt;
-                break;
+            }
-            case 2:
+            case 2 -> {
                 boolean randomBoolean = randomBoolean();
                 randomValue = randomBoolean;
-                break;
+            }
-            default:
+            default -> throw new UnsupportedOperationException();
-                throw new UnsupportedOperationException();
         }
         IngestDocument ingestDocument = RandomDocumentPicks.randomIngestDocument(random(), Collections.singletonMap("field", randomValue));
         Processor processor = new ConvertProcessor(randomAlphaOfLength(10), null, "field", "field", Type.AUTO, false);

modules/ingest-geoip/src/main/java/org/elasticsearch/ingest/geoip/GeoIpProcessor.java

@@ -224,28 +224,26 @@ public final class GeoIpProcessor extends AbstractProcessor {
         Map<String, Object> geoData = new HashMap<>();
         for (Property property : this.properties) {
             switch (property) {
-                case IP:
+                case IP -> geoData.put("ip", NetworkAddress.format(ipAddress));
-                    geoData.put("ip", NetworkAddress.format(ipAddress));
+                case COUNTRY_ISO_CODE -> {
-                    break;
-                case COUNTRY_ISO_CODE:
                     String countryIsoCode = country.getIsoCode();
                     if (countryIsoCode != null) {
                         geoData.put("country_iso_code", countryIsoCode);
                     }
-                    break;
+                }
-                case COUNTRY_NAME:
+                case COUNTRY_NAME -> {
                     String countryName = country.getName();
                     if (countryName != null) {
                         geoData.put("country_name", countryName);
                     }
-                    break;
+                }
-                case CONTINENT_NAME:
+                case CONTINENT_NAME -> {
                     String continentName = continent.getName();
                     if (continentName != null) {
                         geoData.put("continent_name", continentName);
                     }
-                    break;
+                }
-                case REGION_ISO_CODE:
+                case REGION_ISO_CODE -> {
                     // ISO 3166-2 code for country subdivisions.
                     // See iso.org/iso-3166-country-codes.html
                     String countryIso = country.getIsoCode();
@@ -254,26 +252,26 @@ public final class GeoIpProcessor extends AbstractProcessor {
                         String regionIsoCode = countryIso + "-" + subdivisionIso;
                         geoData.put("region_iso_code", regionIsoCode);
                     }
-                    break;
+                }
-                case REGION_NAME:
+                case REGION_NAME -> {
                     String subdivisionName = subdivision.getName();
                     if (subdivisionName != null) {
                         geoData.put("region_name", subdivisionName);
                     }
-                    break;
+                }
-                case CITY_NAME:
+                case CITY_NAME -> {
                     String cityName = city.getName();
                     if (cityName != null) {
                         geoData.put("city_name", cityName);
                     }
-                    break;
+                }
-                case TIMEZONE:
+                case TIMEZONE -> {
                     String locationTimeZone = location.getTimeZone();
                     if (locationTimeZone != null) {
                         geoData.put("timezone", locationTimeZone);
                     }
-                    break;
+                }
-                case LOCATION:
+                case LOCATION -> {
                     Double latitude = location.getLatitude();
                     Double longitude = location.getLongitude();
                     if (latitude != null && longitude != null) {
@@ -282,7 +280,7 @@ public final class GeoIpProcessor extends AbstractProcessor {
                         locationObject.put("lon", longitude);
                         geoData.put("location", locationObject);
                     }
-                    break;
+                }
             }
         }
         return geoData;
@@ -299,27 +297,25 @@ public final class GeoIpProcessor extends AbstractProcessor {
         Map<String, Object> geoData = new HashMap<>();
         for (Property property : this.properties) {
             switch (property) {
-                case IP:
+                case IP -> geoData.put("ip", NetworkAddress.format(ipAddress));
-                    geoData.put("ip", NetworkAddress.format(ipAddress));
+                case COUNTRY_ISO_CODE -> {
-                    break;
-                case COUNTRY_ISO_CODE:
                     String countryIsoCode = country.getIsoCode();
                     if (countryIsoCode != null) {
                         geoData.put("country_iso_code", countryIsoCode);
                     }
-                    break;
+                }
-                case COUNTRY_NAME:
+                case COUNTRY_NAME -> {
                     String countryName = country.getName();
                     if (countryName != null) {
                         geoData.put("country_name", countryName);
                     }
-                    break;
+                }
-                case CONTINENT_NAME:
+                case CONTINENT_NAME -> {
                     String continentName = continent.getName();
                     if (continentName != null) {
                         geoData.put("continent_name", continentName);
                     }
-                    break;
+                }
             }
         }
         return geoData;

modules/lang-expression/src/main/java/org/elasticsearch/script/expression/DateField.java

@@ -45,52 +45,36 @@ final class DateField {
     static final String GET_SECONDS_METHOD = "getSeconds";
 
     static DoubleValuesSource getVariable(IndexFieldData<?> fieldData, String fieldName, String variable) {
-        switch (variable) {
+        return switch (variable) {
-            case VALUE_VARIABLE:
+            case VALUE_VARIABLE -> new FieldDataValueSource(fieldData, MultiValueMode.MIN);
-                return new FieldDataValueSource(fieldData, MultiValueMode.MIN);
+            case EMPTY_VARIABLE -> new EmptyMemberValueSource(fieldData);
-            case EMPTY_VARIABLE:
+            case LENGTH_VARIABLE -> new CountMethodValueSource(fieldData);
-                return new EmptyMemberValueSource(fieldData);
+            default -> throw new IllegalArgumentException(
-            case LENGTH_VARIABLE:
+                "Member variable [" + variable + "] does not exist for date field [" + fieldName + "]."
-                return new CountMethodValueSource(fieldData);
+            );
-            default:
+        };
-                throw new IllegalArgumentException("Member variable [" + variable + "] does not exist for date field [" + fieldName + "].");
-        }
     }
 
     static DoubleValuesSource getMethod(IndexFieldData<?> fieldData, String fieldName, String method) {
-        switch (method) {
+        return switch (method) {
-            case GETVALUE_METHOD:
+            case GETVALUE_METHOD -> new FieldDataValueSource(fieldData, MultiValueMode.MIN);
-                return new FieldDataValueSource(fieldData, MultiValueMode.MIN);
+            case ISEMPTY_METHOD -> new EmptyMemberValueSource(fieldData);
-            case ISEMPTY_METHOD:
+            case SIZE_METHOD -> new CountMethodValueSource(fieldData);
-                return new EmptyMemberValueSource(fieldData);
+            case MINIMUM_METHOD -> new FieldDataValueSource(fieldData, MultiValueMode.MIN);
-            case SIZE_METHOD:
+            case MAXIMUM_METHOD -> new FieldDataValueSource(fieldData, MultiValueMode.MAX);
-                return new CountMethodValueSource(fieldData);
+            case AVERAGE_METHOD -> new FieldDataValueSource(fieldData, MultiValueMode.AVG);
-            case MINIMUM_METHOD:
+            case MEDIAN_METHOD -> new FieldDataValueSource(fieldData, MultiValueMode.MEDIAN);
-                return new FieldDataValueSource(fieldData, MultiValueMode.MIN);
+            case SUM_METHOD -> new FieldDataValueSource(fieldData, MultiValueMode.SUM);
-            case MAXIMUM_METHOD:
+            case COUNT_METHOD -> new CountMethodValueSource(fieldData);
-                return new FieldDataValueSource(fieldData, MultiValueMode.MAX);
+            case GET_YEAR_METHOD -> new DateMethodValueSource(fieldData, MultiValueMode.MIN, method, Calendar.YEAR);
-            case AVERAGE_METHOD:
+            case GET_MONTH_METHOD -> new DateMethodValueSource(fieldData, MultiValueMode.MIN, method, Calendar.MONTH);
-                return new FieldDataValueSource(fieldData, MultiValueMode.AVG);
+            case GET_DAY_OF_MONTH_METHOD -> new DateMethodValueSource(fieldData, MultiValueMode.MIN, method, Calendar.DAY_OF_MONTH);
-            case MEDIAN_METHOD:
+            case GET_HOUR_OF_DAY_METHOD -> new DateMethodValueSource(fieldData, MultiValueMode.MIN, method, Calendar.HOUR_OF_DAY);
-                return new FieldDataValueSource(fieldData, MultiValueMode.MEDIAN);
+            case GET_MINUTES_METHOD -> new DateMethodValueSource(fieldData, MultiValueMode.MIN, method, Calendar.MINUTE);
-            case SUM_METHOD:
+            case GET_SECONDS_METHOD -> new DateMethodValueSource(fieldData, MultiValueMode.MIN, method, Calendar.SECOND);
-                return new FieldDataValueSource(fieldData, MultiValueMode.SUM);
+            default -> throw new IllegalArgumentException(
-            case COUNT_METHOD:
+                "Member method [" + method + "] does not exist for date field [" + fieldName + "]."
-                return new CountMethodValueSource(fieldData);
+            );
-            case GET_YEAR_METHOD:
+        };
-                return new DateMethodValueSource(fieldData, MultiValueMode.MIN, method, Calendar.YEAR);
-            case GET_MONTH_METHOD:
-                return new DateMethodValueSource(fieldData, MultiValueMode.MIN, method, Calendar.MONTH);
-            case GET_DAY_OF_MONTH_METHOD:
-                return new DateMethodValueSource(fieldData, MultiValueMode.MIN, method, Calendar.DAY_OF_MONTH);
-            case GET_HOUR_OF_DAY_METHOD:
-                return new DateMethodValueSource(fieldData, MultiValueMode.MIN, method, Calendar.HOUR_OF_DAY);
-            case GET_MINUTES_METHOD:
-                return new DateMethodValueSource(fieldData, MultiValueMode.MIN, method, Calendar.MINUTE);
-            case GET_SECONDS_METHOD:
-                return new DateMethodValueSource(fieldData, MultiValueMode.MIN, method, Calendar.SECOND);
-            default:
-                throw new IllegalArgumentException("Member method [" + method + "] does not exist for date field [" + fieldName + "].");
-        }
     }
 }

modules/lang-expression/src/main/java/org/elasticsearch/script/expression/DateObject.java

@@ -64,112 +64,154 @@ final class DateObject {
     static final String GETYEAR_OF_ERA_METHOD = "getYearOfEra";
 
     static DoubleValuesSource getVariable(IndexFieldData<?> fieldData, String fieldName, String variable) {
-        switch (variable) {
+        return switch (variable) {
-            case CENTURY_OF_ERA_VARIABLE:
+            case CENTURY_OF_ERA_VARIABLE -> new DateObjectValueSource(
-                return new DateObjectValueSource(fieldData, MultiValueMode.MIN, variable, zdt -> zdt.get(ChronoField.YEAR_OF_ERA) / 100);
+                fieldData,
-            case DAY_OF_MONTH_VARIABLE:
+                MultiValueMode.MIN,
-                return new DateObjectValueSource(fieldData, MultiValueMode.MIN, variable, ZonedDateTime::getDayOfMonth);
+                variable,
-            case DAY_OF_WEEK_VARIABLE:
+                zdt -> zdt.get(ChronoField.YEAR_OF_ERA) / 100
-                return new DateObjectValueSource(fieldData, MultiValueMode.MIN, variable, zdt -> zdt.getDayOfWeek().getValue());
+            );
-            case DAY_OF_YEAR_VARIABLE:
+            case DAY_OF_MONTH_VARIABLE -> new DateObjectValueSource(fieldData, MultiValueMode.MIN, variable, ZonedDateTime::getDayOfMonth);
-                return new DateObjectValueSource(fieldData, MultiValueMode.MIN, variable, ZonedDateTime::getDayOfYear);
+            case DAY_OF_WEEK_VARIABLE -> new DateObjectValueSource(
-            case ERA_VARIABLE:
+                fieldData,
-                return new DateObjectValueSource(fieldData, MultiValueMode.MIN, variable, zdt -> zdt.get(ChronoField.ERA));
+                MultiValueMode.MIN,
-            case HOUR_OF_DAY_VARIABLE:
+                variable,
-                return new DateObjectValueSource(fieldData, MultiValueMode.MIN, variable, ZonedDateTime::getHour);
+                zdt -> zdt.getDayOfWeek().getValue()
-            case MILLIS_OF_DAY_VARIABLE:
+            );
-                return new DateObjectValueSource(fieldData, MultiValueMode.MIN, variable, zdt -> zdt.get(ChronoField.MILLI_OF_DAY));
+            case DAY_OF_YEAR_VARIABLE -> new DateObjectValueSource(fieldData, MultiValueMode.MIN, variable, ZonedDateTime::getDayOfYear);
-            case MILLIS_OF_SECOND_VARIABLE:
+            case ERA_VARIABLE -> new DateObjectValueSource(fieldData, MultiValueMode.MIN, variable, zdt -> zdt.get(ChronoField.ERA));
-                return new DateObjectValueSource(fieldData, MultiValueMode.MIN, variable, zdt -> zdt.get(ChronoField.MILLI_OF_SECOND));
+            case HOUR_OF_DAY_VARIABLE -> new DateObjectValueSource(fieldData, MultiValueMode.MIN, variable, ZonedDateTime::getHour);
-            case MINUTE_OF_DAY_VARIABLE:
+            case MILLIS_OF_DAY_VARIABLE -> new DateObjectValueSource(
-                return new DateObjectValueSource(fieldData, MultiValueMode.MIN, variable, zdt -> zdt.get(ChronoField.MINUTE_OF_DAY));
+                fieldData,
-            case MINUTE_OF_HOUR_VARIABLE:
+                MultiValueMode.MIN,
-                return new DateObjectValueSource(fieldData, MultiValueMode.MIN, variable, ZonedDateTime::getMinute);
+                variable,
-            case MONTH_OF_YEAR_VARIABLE:
+                zdt -> zdt.get(ChronoField.MILLI_OF_DAY)
-                return new DateObjectValueSource(fieldData, MultiValueMode.MIN, variable, ZonedDateTime::getMonthValue);
+            );
-            case SECOND_OF_DAY_VARIABLE:
+            case MILLIS_OF_SECOND_VARIABLE -> new DateObjectValueSource(
-                return new DateObjectValueSource(fieldData, MultiValueMode.MIN, variable, zdt -> zdt.get(ChronoField.SECOND_OF_DAY));
+                fieldData,
-            case SECOND_OF_MINUTE_VARIABLE:
+                MultiValueMode.MIN,
-                return new DateObjectValueSource(fieldData, MultiValueMode.MIN, variable, ZonedDateTime::getSecond);
+                variable,
-            case WEEK_OF_WEEK_YEAR_VARIABLE:
+                zdt -> zdt.get(ChronoField.MILLI_OF_SECOND)
-                return new DateObjectValueSource(
+            );
+            case MINUTE_OF_DAY_VARIABLE -> new DateObjectValueSource(
+                fieldData,
+                MultiValueMode.MIN,
+                variable,
+                zdt -> zdt.get(ChronoField.MINUTE_OF_DAY)
+            );
+            case MINUTE_OF_HOUR_VARIABLE -> new DateObjectValueSource(fieldData, MultiValueMode.MIN, variable, ZonedDateTime::getMinute);
+            case MONTH_OF_YEAR_VARIABLE -> new DateObjectValueSource(fieldData, MultiValueMode.MIN, variable, ZonedDateTime::getMonthValue);
+            case SECOND_OF_DAY_VARIABLE -> new DateObjectValueSource(
+                fieldData,
+                MultiValueMode.MIN,
+                variable,
+                zdt -> zdt.get(ChronoField.SECOND_OF_DAY)
+            );
+            case SECOND_OF_MINUTE_VARIABLE -> new DateObjectValueSource(fieldData, MultiValueMode.MIN, variable, ZonedDateTime::getSecond);
+            case WEEK_OF_WEEK_YEAR_VARIABLE -> new DateObjectValueSource(
                 fieldData,
                 MultiValueMode.MIN,
                 variable,
                 zdt -> zdt.get(DateFormatters.WEEK_FIELDS_ROOT.weekOfWeekBasedYear())
             );
-            case WEEK_YEAR_VARIABLE:
+            case WEEK_YEAR_VARIABLE -> new DateObjectValueSource(
-                return new DateObjectValueSource(
                 fieldData,
                 MultiValueMode.MIN,
                 variable,
                 zdt -> zdt.get(DateFormatters.WEEK_FIELDS_ROOT.weekBasedYear())
             );
-            case YEAR_VARIABLE:
+            case YEAR_VARIABLE -> new DateObjectValueSource(fieldData, MultiValueMode.MIN, variable, ZonedDateTime::getYear);
-                return new DateObjectValueSource(fieldData, MultiValueMode.MIN, variable, ZonedDateTime::getYear);
+            case YEAR_OF_CENTURY_VARIABLE -> new DateObjectValueSource(
-            case YEAR_OF_CENTURY_VARIABLE:
+                fieldData,
-                return new DateObjectValueSource(fieldData, MultiValueMode.MIN, variable, zdt -> zdt.get(ChronoField.YEAR_OF_ERA) % 100);
+                MultiValueMode.MIN,
-            case YEAR_OF_ERA_VARIABLE:
+                variable,
-                return new DateObjectValueSource(fieldData, MultiValueMode.MIN, variable, zdt -> zdt.get(ChronoField.YEAR_OF_ERA));
+                zdt -> zdt.get(ChronoField.YEAR_OF_ERA) % 100
-            default:
+            );
-                throw new IllegalArgumentException(
+            case YEAR_OF_ERA_VARIABLE -> new DateObjectValueSource(
+                fieldData,
+                MultiValueMode.MIN,
+                variable,
+                zdt -> zdt.get(ChronoField.YEAR_OF_ERA)
+            );
+            default -> throw new IllegalArgumentException(
                 "Member variable [" + variable + "] does not exist for date object on field [" + fieldName + "]."
             );
-        }
+        };
     }
 
     static DoubleValuesSource getMethod(IndexFieldData<?> fieldData, String fieldName, String method) {
-        switch (method) {
+        return switch (method) {
-            case GETCENTURY_OF_ERA_METHOD:
+            case GETCENTURY_OF_ERA_METHOD -> new DateObjectValueSource(
-                return new DateObjectValueSource(fieldData, MultiValueMode.MIN, method, zdt -> zdt.get(ChronoField.YEAR_OF_ERA) / 100);
+                fieldData,
-            case GETDAY_OF_MONTH_METHOD:
+                MultiValueMode.MIN,
-                return new DateObjectValueSource(fieldData, MultiValueMode.MIN, method, ZonedDateTime::getDayOfMonth);
+                method,
-            case GETDAY_OF_WEEK_METHOD:
+                zdt -> zdt.get(ChronoField.YEAR_OF_ERA) / 100
-                return new DateObjectValueSource(fieldData, MultiValueMode.MIN, method, zdt -> zdt.getDayOfWeek().getValue());
+            );
-            case GETDAY_OF_YEAR_METHOD:
+            case GETDAY_OF_MONTH_METHOD -> new DateObjectValueSource(fieldData, MultiValueMode.MIN, method, ZonedDateTime::getDayOfMonth);
-                return new DateObjectValueSource(fieldData, MultiValueMode.MIN, method, ZonedDateTime::getDayOfYear);
+            case GETDAY_OF_WEEK_METHOD -> new DateObjectValueSource(
-            case GETERA_METHOD:
+                fieldData,
-                return new DateObjectValueSource(fieldData, MultiValueMode.MIN, method, zdt -> zdt.get(ChronoField.ERA));
+                MultiValueMode.MIN,
-            case GETHOUR_OF_DAY_METHOD:
+                method,
-                return new DateObjectValueSource(fieldData, MultiValueMode.MIN, method, ZonedDateTime::getHour);
+                zdt -> zdt.getDayOfWeek().getValue()
-            case GETMILLIS_OF_DAY_METHOD:
+            );
-                return new DateObjectValueSource(fieldData, MultiValueMode.MIN, method, zdt -> zdt.get(ChronoField.MILLI_OF_DAY));
+            case GETDAY_OF_YEAR_METHOD -> new DateObjectValueSource(fieldData, MultiValueMode.MIN, method, ZonedDateTime::getDayOfYear);
-            case GETMILLIS_OF_SECOND_METHOD:
+            case GETERA_METHOD -> new DateObjectValueSource(fieldData, MultiValueMode.MIN, method, zdt -> zdt.get(ChronoField.ERA));
-                return new DateObjectValueSource(fieldData, MultiValueMode.MIN, method, zdt -> zdt.get(ChronoField.MILLI_OF_SECOND));
+            case GETHOUR_OF_DAY_METHOD -> new DateObjectValueSource(fieldData, MultiValueMode.MIN, method, ZonedDateTime::getHour);
-            case GETMINUTE_OF_DAY_METHOD:
+            case GETMILLIS_OF_DAY_METHOD -> new DateObjectValueSource(
-                return new DateObjectValueSource(fieldData, MultiValueMode.MIN, method, zdt -> zdt.get(ChronoField.MINUTE_OF_DAY));
+                fieldData,
-            case GETMINUTE_OF_HOUR_METHOD:
+                MultiValueMode.MIN,
-                return new DateObjectValueSource(fieldData, MultiValueMode.MIN, method, ZonedDateTime::getMinute);
+                method,
-            case GETMONTH_OF_YEAR_METHOD:
+                zdt -> zdt.get(ChronoField.MILLI_OF_DAY)
-                return new DateObjectValueSource(fieldData, MultiValueMode.MIN, method, ZonedDateTime::getMonthValue);
+            );
-            case GETSECOND_OF_DAY_METHOD:
+            case GETMILLIS_OF_SECOND_METHOD -> new DateObjectValueSource(
-                return new DateObjectValueSource(fieldData, MultiValueMode.MIN, method, zdt -> zdt.get(ChronoField.SECOND_OF_DAY));
+                fieldData,
-            case GETSECOND_OF_MINUTE_METHOD:
+                MultiValueMode.MIN,
-                return new DateObjectValueSource(fieldData, MultiValueMode.MIN, method, ZonedDateTime::getSecond);
+                method,
-            case GETWEEK_OF_WEEK_YEAR_METHOD:
+                zdt -> zdt.get(ChronoField.MILLI_OF_SECOND)
-                return new DateObjectValueSource(
+            );
+            case GETMINUTE_OF_DAY_METHOD -> new DateObjectValueSource(
+                fieldData,
+                MultiValueMode.MIN,
+                method,
+                zdt -> zdt.get(ChronoField.MINUTE_OF_DAY)
+            );
+            case GETMINUTE_OF_HOUR_METHOD -> new DateObjectValueSource(fieldData, MultiValueMode.MIN, method, ZonedDateTime::getMinute);
+            case GETMONTH_OF_YEAR_METHOD -> new DateObjectValueSource(fieldData, MultiValueMode.MIN, method, ZonedDateTime::getMonthValue);
+            case GETSECOND_OF_DAY_METHOD -> new DateObjectValueSource(
+                fieldData,
+                MultiValueMode.MIN,
+                method,
+                zdt -> zdt.get(ChronoField.SECOND_OF_DAY)
+            );
+            case GETSECOND_OF_MINUTE_METHOD -> new DateObjectValueSource(fieldData, MultiValueMode.MIN, method, ZonedDateTime::getSecond);
+            case GETWEEK_OF_WEEK_YEAR_METHOD -> new DateObjectValueSource(
                 fieldData,
                 MultiValueMode.MIN,
                 method,
                 zdt -> zdt.get(DateFormatters.WEEK_FIELDS_ROOT.weekOfWeekBasedYear())
             );
-            case GETWEEK_YEAR_METHOD:
+            case GETWEEK_YEAR_METHOD -> new DateObjectValueSource(
-                return new DateObjectValueSource(
                 fieldData,
                 MultiValueMode.MIN,
                 method,
                 zdt -> zdt.get(DateFormatters.WEEK_FIELDS_ROOT.weekBasedYear())
             );
-            case GETYEAR_METHOD:
+            case GETYEAR_METHOD -> new DateObjectValueSource(fieldData, MultiValueMode.MIN, method, ZonedDateTime::getYear);
-                return new DateObjectValueSource(fieldData, MultiValueMode.MIN, method, ZonedDateTime::getYear);
+            case GETYEAR_OF_CENTURY_METHOD -> new DateObjectValueSource(
-            case GETYEAR_OF_CENTURY_METHOD:
+                fieldData,
-                return new DateObjectValueSource(fieldData, MultiValueMode.MIN, method, zdt -> zdt.get(ChronoField.YEAR_OF_ERA) % 100);
+                MultiValueMode.MIN,
-            case GETYEAR_OF_ERA_METHOD:
+                method,
-                return new DateObjectValueSource(fieldData, MultiValueMode.MIN, method, zdt -> zdt.get(ChronoField.YEAR_OF_ERA));
+                zdt -> zdt.get(ChronoField.YEAR_OF_ERA) % 100
-            default:
+            );
-                throw new IllegalArgumentException(
+            case GETYEAR_OF_ERA_METHOD -> new DateObjectValueSource(
+                fieldData,
+                MultiValueMode.MIN,
+                method,
+                zdt -> zdt.get(ChronoField.YEAR_OF_ERA)
+            );
+            default -> throw new IllegalArgumentException(
                 "Member method [" + method + "] does not exist for date object on field [" + fieldName + "]."
             );
-        }
+        };
     }
 }

modules/lang-expression/src/main/java/org/elasticsearch/script/expression/GeoField.java

@@ -29,28 +29,24 @@ final class GeoField {
     static final String GETLON_METHOD = "getLon";
 
     static DoubleValuesSource getVariable(IndexFieldData<?> fieldData, String fieldName, String variable) {
-        switch (variable) {
+        return switch (variable) {
-            case EMPTY_VARIABLE:
+            case EMPTY_VARIABLE -> new GeoEmptyValueSource(fieldData);
-                return new GeoEmptyValueSource(fieldData);
+            case LAT_VARIABLE -> new GeoLatitudeValueSource(fieldData);
-            case LAT_VARIABLE:
+            case LON_VARIABLE -> new GeoLongitudeValueSource(fieldData);
-                return new GeoLatitudeValueSource(fieldData);
+            default -> throw new IllegalArgumentException(
-            case LON_VARIABLE:
+                "Member variable [" + variable + "] does not exist for geo field [" + fieldName + "]."
-                return new GeoLongitudeValueSource(fieldData);
+            );
-            default:
+        };
-                throw new IllegalArgumentException("Member variable [" + variable + "] does not exist for geo field [" + fieldName + "].");
-        }
     }
 
     static DoubleValuesSource getMethod(IndexFieldData<?> fieldData, String fieldName, String method) {
-        switch (method) {
+        return switch (method) {
-            case ISEMPTY_METHOD:
+            case ISEMPTY_METHOD -> new GeoEmptyValueSource(fieldData);
-                return new GeoEmptyValueSource(fieldData);
+            case GETLAT_METHOD -> new GeoLatitudeValueSource(fieldData);
-            case GETLAT_METHOD:
+            case GETLON_METHOD -> new GeoLongitudeValueSource(fieldData);
-                return new GeoLatitudeValueSource(fieldData);
+            default -> throw new IllegalArgumentException(
-            case GETLON_METHOD:
+                "Member method [" + method + "] does not exist for geo field [" + fieldName + "]."
-                return new GeoLongitudeValueSource(fieldData);
+            );
-            default:
+        };
-                throw new IllegalArgumentException("Member method [" + method + "] does not exist for geo field [" + fieldName + "].");
-        }
     }
 }

modules/lang-expression/src/main/java/org/elasticsearch/script/expression/NumericField.java

@@ -36,42 +36,30 @@ final class NumericField {
     static final String COUNT_METHOD = "count";
 
     static DoubleValuesSource getVariable(IndexFieldData<?> fieldData, String fieldName, String variable) {
-        switch (variable) {
+        return switch (variable) {
-            case VALUE_VARIABLE:
+            case VALUE_VARIABLE -> new FieldDataValueSource(fieldData, MultiValueMode.MIN);
-                return new FieldDataValueSource(fieldData, MultiValueMode.MIN);
+            case EMPTY_VARIABLE -> new EmptyMemberValueSource(fieldData);
-            case EMPTY_VARIABLE:
+            case LENGTH_VARIABLE -> new CountMethodValueSource(fieldData);
-                return new EmptyMemberValueSource(fieldData);
+            default -> throw new IllegalArgumentException(
-            case LENGTH_VARIABLE:
-                return new CountMethodValueSource(fieldData);
-            default:
-                throw new IllegalArgumentException(
                 "Member variable [" + variable + "] does not exist for " + "numeric field [" + fieldName + "]."
             );
-        }
+        };
     }
 
     static DoubleValuesSource getMethod(IndexFieldData<?> fieldData, String fieldName, String method) {
-        switch (method) {
+        return switch (method) {
-            case GETVALUE_METHOD:
+            case GETVALUE_METHOD -> new FieldDataValueSource(fieldData, MultiValueMode.MIN);
-                return new FieldDataValueSource(fieldData, MultiValueMode.MIN);
+            case ISEMPTY_METHOD -> new EmptyMemberValueSource(fieldData);
-            case ISEMPTY_METHOD:
+            case SIZE_METHOD -> new CountMethodValueSource(fieldData);
-                return new EmptyMemberValueSource(fieldData);
+            case MINIMUM_METHOD -> new FieldDataValueSource(fieldData, MultiValueMode.MIN);
-            case SIZE_METHOD:
+            case MAXIMUM_METHOD -> new FieldDataValueSource(fieldData, MultiValueMode.MAX);
-                return new CountMethodValueSource(fieldData);
+            case AVERAGE_METHOD -> new FieldDataValueSource(fieldData, MultiValueMode.AVG);
-            case MINIMUM_METHOD:
+            case MEDIAN_METHOD -> new FieldDataValueSource(fieldData, MultiValueMode.MEDIAN);
-                return new FieldDataValueSource(fieldData, MultiValueMode.MIN);
+            case SUM_METHOD -> new FieldDataValueSource(fieldData, MultiValueMode.SUM);
-            case MAXIMUM_METHOD:
+            case COUNT_METHOD -> new CountMethodValueSource(fieldData);
-                return new FieldDataValueSource(fieldData, MultiValueMode.MAX);
+            default -> throw new IllegalArgumentException(
-            case AVERAGE_METHOD:
+                "Member method [" + method + "] does not exist for numeric field [" + fieldName + "]."
-                return new FieldDataValueSource(fieldData, MultiValueMode.AVG);
+            );
-            case MEDIAN_METHOD:
+        };
-                return new FieldDataValueSource(fieldData, MultiValueMode.MEDIAN);
-            case SUM_METHOD:
-                return new FieldDataValueSource(fieldData, MultiValueMode.SUM);
-            case COUNT_METHOD:
-                return new CountMethodValueSource(fieldData);
-            default:
-                throw new IllegalArgumentException("Member method [" + method + "] does not exist for numeric field [" + fieldName + "].");
-        }
     }
 }

modules/lang-painless/src/main/java/org/elasticsearch/painless/DefBootstrap.java

@@ -156,21 +156,23 @@ public final class DefBootstrap {
          * Does a slow lookup against the whitelist.
          */
         private MethodHandle lookup(int flavorValue, String nameValue, Class<?> receiver) throws Throwable {
-            switch (flavorValue) {
+            return switch (flavorValue) {
-                case METHOD_CALL:
+                case METHOD_CALL -> Def.lookupMethod(
-                    return Def.lookupMethod(painlessLookup, functions, constants, methodHandlesLookup, type(), receiver, nameValue, args);
+                    painlessLookup,
-                case LOAD:
+                    functions,
-                    return Def.lookupGetter(painlessLookup, receiver, nameValue);
+                    constants,
-                case STORE:
+                    methodHandlesLookup,
-                    return Def.lookupSetter(painlessLookup, receiver, nameValue);
+                    type(),
-                case ARRAY_LOAD:
+                    receiver,
-                    return Def.lookupArrayLoad(receiver);
+                    nameValue,
-                case ARRAY_STORE:
+                    args
-                    return Def.lookupArrayStore(receiver);
+                );
-                case ITERATOR:
+                case LOAD -> Def.lookupGetter(painlessLookup, receiver, nameValue);
-                    return Def.lookupIterator(receiver);
+                case STORE -> Def.lookupSetter(painlessLookup, receiver, nameValue);
-                case REFERENCE:
+                case ARRAY_LOAD -> Def.lookupArrayLoad(receiver);
-                    return Def.lookupReference(
+                case ARRAY_STORE -> Def.lookupArrayStore(receiver);
+                case ITERATOR -> Def.lookupIterator(receiver);
+                case REFERENCE -> Def.lookupReference(
                     painlessLookup,
                     functions,
                     constants,
@@ -179,11 +181,9 @@ public final class DefBootstrap {
                     receiver,
                     nameValue
                 );
-                case INDEX_NORMALIZE:
+                case INDEX_NORMALIZE -> Def.lookupIndexNormalize(receiver);
-                    return Def.lookupIndexNormalize(receiver);
+                default -> throw new AssertionError();
-                default:
+            };
-                    throw new AssertionError();
-            }
         }
 
         /**
@@ -493,7 +493,7 @@ public final class DefBootstrap {
         // validate arguments
         switch (flavor) {
             // "function-call" like things get a polymorphic cache
-            case METHOD_CALL:
+            case METHOD_CALL -> {
                 if (args.length == 0) {
                     throw new BootstrapMethodError("Invalid number of parameters for method call");
                 }
@@ -509,17 +509,14 @@ public final class DefBootstrap {
                     throw new BootstrapMethodError("Illegal number of parameters: expected " + numLambdas + " references");
                 }
                 return new PIC(painlessLookup, functions, constants, methodHandlesLookup, name, type, initialDepth, flavor, args);
-            case LOAD:
+            }
-            case STORE:
+            case LOAD, STORE, ARRAY_LOAD, ARRAY_STORE, ITERATOR, INDEX_NORMALIZE -> {
-            case ARRAY_LOAD:
-            case ARRAY_STORE:
-            case ITERATOR:
-            case INDEX_NORMALIZE:
                 if (args.length > 0) {
                     throw new BootstrapMethodError("Illegal static bootstrap parameters for flavor: " + flavor);
                 }
                 return new PIC(painlessLookup, functions, constants, methodHandlesLookup, name, type, initialDepth, flavor, args);
-            case REFERENCE:
+            }
+            case REFERENCE -> {
                 if (args.length != 1) {
                     throw new BootstrapMethodError("Invalid number of parameters for reference call");
                 }
@@ -527,11 +524,10 @@ public final class DefBootstrap {
                     throw new BootstrapMethodError("Illegal parameter for reference call: " + args[0]);
                 }
                 return new PIC(painlessLookup, functions, constants, methodHandlesLookup, name, type, initialDepth, flavor, args);
+            }
 
             // operators get monomorphic cache, with a generic impl for a fallback
-            case UNARY_OPERATOR:
+            case UNARY_OPERATOR, SHIFT_OPERATOR, BINARY_OPERATOR -> {
-            case SHIFT_OPERATOR:
-            case BINARY_OPERATOR:
                 if (args.length != 1) {
                     throw new BootstrapMethodError("Invalid number of parameters for operator call");
                 }
@@ -548,8 +544,8 @@ public final class DefBootstrap {
                     throw new BootstrapMethodError("This parameter is only supported for BINARY/SHIFT_OPERATORs");
                 }
                 return new MIC(name, type, initialDepth, flavor, flags);
-            default:
+            }
-                throw new BootstrapMethodError("Illegal static bootstrap parameter for flavor: " + flavor);
+            default -> throw new BootstrapMethodError("Illegal static bootstrap parameter for flavor: " + flavor);
         }
     }
 }

modules/lang-painless/src/main/java/org/elasticsearch/painless/MethodWriter.java

@@ -331,16 +331,10 @@ public final class MethodWriter extends GeneratorAdapter {
         Type methodType = Type.getMethodType(getType(returnType), getType(lhs), getType(rhs));
 
         switch (operation) {
-            case MUL:
+            case MUL -> invokeDefCall("mul", methodType, DefBootstrap.BINARY_OPERATOR, flags);
-                invokeDefCall("mul", methodType, DefBootstrap.BINARY_OPERATOR, flags);
+            case DIV -> invokeDefCall("div", methodType, DefBootstrap.BINARY_OPERATOR, flags);
-                break;
+            case REM -> invokeDefCall("rem", methodType, DefBootstrap.BINARY_OPERATOR, flags);
-            case DIV:
+            case ADD -> {
-                invokeDefCall("div", methodType, DefBootstrap.BINARY_OPERATOR, flags);
-                break;
-            case REM:
-                invokeDefCall("rem", methodType, DefBootstrap.BINARY_OPERATOR, flags);
-                break;
-            case ADD:
                 // if either side is primitive, then the + operator should always throw NPE on null,
                 // so we don't need a special NPE guard.
                 // otherwise, we need to allow nulls for possible string concatenation.
@@ -349,30 +343,15 @@ public final class MethodWriter extends GeneratorAdapter {
                     flags |= DefBootstrap.OPERATOR_ALLOWS_NULL;
                 }
                 invokeDefCall("add", methodType, DefBootstrap.BINARY_OPERATOR, flags);
-                break;
+            }
-            case SUB:
+            case SUB -> invokeDefCall("sub", methodType, DefBootstrap.BINARY_OPERATOR, flags);
-                invokeDefCall("sub", methodType, DefBootstrap.BINARY_OPERATOR, flags);
+            case LSH -> invokeDefCall("lsh", methodType, DefBootstrap.SHIFT_OPERATOR, flags);
-                break;
+            case USH -> invokeDefCall("ush", methodType, DefBootstrap.SHIFT_OPERATOR, flags);
-            case LSH:
+            case RSH -> invokeDefCall("rsh", methodType, DefBootstrap.SHIFT_OPERATOR, flags);
-                invokeDefCall("lsh", methodType, DefBootstrap.SHIFT_OPERATOR, flags);
+            case BWAND -> invokeDefCall("and", methodType, DefBootstrap.BINARY_OPERATOR, flags);
-                break;
+            case XOR -> invokeDefCall("xor", methodType, DefBootstrap.BINARY_OPERATOR, flags);
-            case USH:
+            case BWOR -> invokeDefCall("or", methodType, DefBootstrap.BINARY_OPERATOR, flags);
-                invokeDefCall("ush", methodType, DefBootstrap.SHIFT_OPERATOR, flags);
+            default -> throw location.createError(new IllegalStateException("Illegal tree structure."));
-                break;
-            case RSH:
-                invokeDefCall("rsh", methodType, DefBootstrap.SHIFT_OPERATOR, flags);
-                break;
-            case BWAND:
-                invokeDefCall("and", methodType, DefBootstrap.BINARY_OPERATOR, flags);
-                break;
-            case XOR:
-                invokeDefCall("xor", methodType, DefBootstrap.BINARY_OPERATOR, flags);
-                break;
-            case BWOR:
-                invokeDefCall("or", methodType, DefBootstrap.BINARY_OPERATOR, flags);
-                break;
-            default:
-                throw location.createError(new IllegalStateException("Illegal tree structure."));
         }
     }
 
@@ -389,41 +368,18 @@ public final class MethodWriter extends GeneratorAdapter {
         }
 
         switch (operation) {
-            case MUL:
+            case MUL -> math(GeneratorAdapter.MUL, getType(clazz));
-                math(GeneratorAdapter.MUL, getType(clazz));
+            case DIV -> math(GeneratorAdapter.DIV, getType(clazz));
-                break;
+            case REM -> math(GeneratorAdapter.REM, getType(clazz));
-            case DIV:
+            case ADD -> math(GeneratorAdapter.ADD, getType(clazz));
-                math(GeneratorAdapter.DIV, getType(clazz));
+            case SUB -> math(GeneratorAdapter.SUB, getType(clazz));
-                break;
+            case LSH -> math(GeneratorAdapter.SHL, getType(clazz));
-            case REM:
+            case USH -> math(GeneratorAdapter.USHR, getType(clazz));
-                math(GeneratorAdapter.REM, getType(clazz));
+            case RSH -> math(GeneratorAdapter.SHR, getType(clazz));
-                break;
+            case BWAND -> math(GeneratorAdapter.AND, getType(clazz));
-            case ADD:
+            case XOR -> math(GeneratorAdapter.XOR, getType(clazz));
-                math(GeneratorAdapter.ADD, getType(clazz));
+            case BWOR -> math(GeneratorAdapter.OR, getType(clazz));
-                break;
+            default -> throw location.createError(new IllegalStateException("Illegal tree structure."));
-            case SUB:
-                math(GeneratorAdapter.SUB, getType(clazz));
-                break;
-            case LSH:
-                math(GeneratorAdapter.SHL, getType(clazz));
-                break;
-            case USH:
-                math(GeneratorAdapter.USHR, getType(clazz));
-                break;
-            case RSH:
-                math(GeneratorAdapter.SHR, getType(clazz));
-                break;
-            case BWAND:
-                math(GeneratorAdapter.AND, getType(clazz));
-                break;
-            case XOR:
-                math(GeneratorAdapter.XOR, getType(clazz));
-                break;
-            case BWOR:
-                math(GeneratorAdapter.OR, getType(clazz));
-                break;
-            default:
-                throw location.createError(new IllegalStateException("Illegal tree structure."));
         }
     }
 

modules/lang-painless/src/main/java/org/elasticsearch/painless/api/Json.java

@@ -27,20 +27,14 @@ public class Json {
             json
         );
 
-        switch (parser.nextToken()) {
+        return switch (parser.nextToken()) {
-            case START_ARRAY:
+            case START_ARRAY -> parser.list();
-                return parser.list();
+            case START_OBJECT -> parser.map();
-            case START_OBJECT:
+            case VALUE_NUMBER -> parser.numberValue();
-                return parser.map();
+            case VALUE_BOOLEAN -> parser.booleanValue();
-            case VALUE_NUMBER:
+            case VALUE_STRING -> parser.text();
-                return parser.numberValue();
+            default -> null;
-            case VALUE_BOOLEAN:
+        };
-                return parser.booleanValue();
-            case VALUE_STRING:
-                return parser.text();
-            default:
-                return null;
-        }
     }
 
     /**

modules/lang-painless/src/main/java/org/elasticsearch/painless/phase/DefaultSemanticAnalysisPhase.java

@@ -2282,34 +2282,17 @@ public class DefaultSemanticAnalysisPhase extends UserTreeBaseVisitor<SemanticSc
         for (int i = 0; i < flags.length(); ++i) {
             char flag = flags.charAt(i);
 
-            switch (flag) {
+            regexFlags |= switch (flag) {
-                case 'c':
+                case 'c' -> Pattern.CANON_EQ;
-                    regexFlags |= Pattern.CANON_EQ;
+                case 'i' -> Pattern.CASE_INSENSITIVE;
-                    break;
+                case 'l' -> Pattern.LITERAL;
-                case 'i':
+                case 'm' -> Pattern.MULTILINE;
-                    regexFlags |= Pattern.CASE_INSENSITIVE;
+                case 's' -> Pattern.DOTALL;
-                    break;
+                case 'U' -> Pattern.UNICODE_CHARACTER_CLASS;
-                case 'l':
+                case 'u' -> Pattern.UNICODE_CASE;
-                    regexFlags |= Pattern.LITERAL;
+                case 'x' -> Pattern.COMMENTS;
-                    break;
+                default -> throw new IllegalArgumentException("invalid regular expression: unknown flag [" + flag + "]");
-                case 'm':
+            };
-                    regexFlags |= Pattern.MULTILINE;
-                    break;
-                case 's':
-                    regexFlags |= Pattern.DOTALL;
-                    break;
-                case 'U':
-                    regexFlags |= Pattern.UNICODE_CHARACTER_CLASS;
-                    break;
-                case 'u':
-                    regexFlags |= Pattern.UNICODE_CASE;
-                    break;
-                case 'x':
-                    regexFlags |= Pattern.COMMENTS;
-                    break;
-                default:
-                    throw new IllegalArgumentException("invalid regular expression: unknown flag [" + flag + "]");
-            }
         }
 
         Pattern compiled;

modules/lang-painless/src/test/java/org/elasticsearch/painless/ListTests.java

@@ -31,22 +31,15 @@ public class ListTests extends ArrayLikeObjectTestCase {
     }
 
     private String fillValue(String valueType) {
-        switch (valueType) {
+        return switch (valueType) {
-            case "int":
+            case "int" -> "0";
-                return "0";
+            case "long" -> "0L";
-            case "long":
+            case "short" -> "(short) 0";
-                return "0L";
+            case "byte" -> "(byte) 0";
-            case "short":
+            case "float" -> "0.0f";
-                return "(short) 0";
+            case "double" -> "0.0"; // Double is implicit for decimal constants
-            case "byte":
+            default -> null;
-                return "(byte) 0";
+        };
-            case "float":
-                return "0.0f";
-            case "double":
-                return "0.0"; // Double is implicit for decimal constants
-            default:
-                return null;
-        }
     }
 
     @Override

modules/lang-painless/src/test/java/org/elasticsearch/painless/action/PainlessExecuteResponseTests.java

@@ -22,20 +22,12 @@ public class PainlessExecuteResponseTests extends AbstractSerializingTestCase<Pa
 
     @Override
     protected PainlessExecuteAction.Response createTestInstance() {
-        Object result;
+        Object result = switch (randomIntBetween(0, 2)) {
-        switch (randomIntBetween(0, 2)) {
+            case 0 -> randomAlphaOfLength(10);
-            case 0:
+            case 1 -> randomBoolean();
-                result = randomAlphaOfLength(10);
+            case 2 -> randomDoubleBetween(-10, 10, true);
-                break;
+            default -> throw new IllegalStateException("invalid branch");
-            case 1:
+        };
-                result = randomBoolean();
-                break;
-            case 2:
-                result = randomDoubleBetween(-10, 10, true);
-                break;
-            default:
-                throw new IllegalStateException("invalid branch");
-        }
         return new PainlessExecuteAction.Response(result);
     }
 
@@ -44,20 +36,12 @@ public class PainlessExecuteResponseTests extends AbstractSerializingTestCase<Pa
         parser.nextToken(); // START-OBJECT
         parser.nextToken(); // FIELD-NAME
         XContentParser.Token token = parser.nextToken(); // result value
-        Object result;
+        Object result = switch (token) {
-        switch (token) {
+            case VALUE_STRING -> parser.text();
-            case VALUE_STRING:
+            case VALUE_BOOLEAN -> parser.booleanValue();
-                result = parser.text();
+            case VALUE_NUMBER -> parser.doubleValue();
-                break;
+            default -> throw new IOException("invalid response");
-            case VALUE_BOOLEAN:
+        };
-                result = parser.booleanValue();
-                break;
-            case VALUE_NUMBER:
-                result = parser.doubleValue();
-                break;
-            default:
-                throw new IOException("invalid response");
-        }
         return new PainlessExecuteAction.Response(result);
     }
 }

modules/legacy-geo/src/main/java/org/elasticsearch/legacygeo/mapper/LegacyGeoShapeFieldMapper.java

@@ -112,15 +112,11 @@ public class LegacyGeoShapeFieldMapper extends AbstractShapeGeometryFieldMapper<
         public static final double DISTANCE_ERROR_PCT = 0.025d;
 
         public static int defaultTreeLevel(String tree) {
-            switch (tree) {
+            return switch (tree) {
-                case PrefixTrees.GEOHASH:
+                case PrefixTrees.GEOHASH -> GEOHASH_TREE_LEVELS;
-                    return GEOHASH_TREE_LEVELS;
+                case PrefixTrees.LEGACY_QUADTREE, PrefixTrees.QUADTREE -> QUADTREE_LEVELS;
-                case PrefixTrees.LEGACY_QUADTREE:
+                default -> throw new IllegalArgumentException("Unknown prefix type [" + tree + "]");
-                case PrefixTrees.QUADTREE:
+            };
-                    return QUADTREE_LEVELS;
-                default:
-                    throw new IllegalArgumentException("Unknown prefix type [" + tree + "]");
-            }
         }
     }
 

modules/legacy-geo/src/main/java/org/elasticsearch/legacygeo/parsers/GeoWKTParser.java

@@ -102,26 +102,17 @@ public class GeoWKTParser {
                 throw new ElasticsearchParseException("Expected geometry type [{}] but found [{}]", shapeType, type);
             }
         }
-        switch (type) {
+        return switch (type) {
-            case POINT:
+            case POINT -> parsePoint(stream, ignoreZValue, coerce);
-                return parsePoint(stream, ignoreZValue, coerce);
+            case MULTIPOINT -> parseMultiPoint(stream, ignoreZValue, coerce);
-            case MULTIPOINT:
+            case LINESTRING -> parseLine(stream, ignoreZValue, coerce);
-                return parseMultiPoint(stream, ignoreZValue, coerce);
+            case MULTILINESTRING -> parseMultiLine(stream, ignoreZValue, coerce);
-            case LINESTRING:
+            case POLYGON -> parsePolygon(stream, ignoreZValue, coerce);
-                return parseLine(stream, ignoreZValue, coerce);
+            case MULTIPOLYGON -> parseMultiPolygon(stream, ignoreZValue, coerce);
-            case MULTILINESTRING:
+            case ENVELOPE -> parseBBox(stream);
-                return parseMultiLine(stream, ignoreZValue, coerce);
+            case GEOMETRYCOLLECTION -> parseGeometryCollection(stream, ignoreZValue, coerce);
-            case POLYGON:
+            default -> throw new IllegalArgumentException("Unknown geometry type: " + type);
-                return parsePolygon(stream, ignoreZValue, coerce);
+        };
-            case MULTIPOLYGON:
-                return parseMultiPolygon(stream, ignoreZValue, coerce);
-            case ENVELOPE:
-                return parseBBox(stream);
-            case GEOMETRYCOLLECTION:
-                return parseGeometryCollection(stream, ignoreZValue, coerce);
-            default:
-                throw new IllegalArgumentException("Unknown geometry type: " + type);
-        }
     }
 
     private static EnvelopeBuilder parseBBox(StreamTokenizer stream) throws IOException, ElasticsearchParseException {
@@ -317,17 +308,13 @@ public class GeoWKTParser {
     }
 
     private static String tokenString(StreamTokenizer stream) {
-        switch (stream.ttype) {
+        return switch (stream.ttype) {
-            case StreamTokenizer.TT_WORD:
+            case StreamTokenizer.TT_WORD -> stream.sval;
-                return stream.sval;
+            case StreamTokenizer.TT_EOF -> EOF;
-            case StreamTokenizer.TT_EOF:
+            case StreamTokenizer.TT_EOL -> EOL;
-                return EOF;
+            case StreamTokenizer.TT_NUMBER -> NUMBER;
-            case StreamTokenizer.TT_EOL:
+            default -> "'" + (char) stream.ttype + "'";
-                return EOL;
+        };
-            case StreamTokenizer.TT_NUMBER:
-                return NUMBER;
-        }
-        return "'" + (char) stream.ttype + "'";
     }
 
     private static boolean isNumberNext(StreamTokenizer stream) throws IOException {

modules/legacy-geo/src/main/java/org/elasticsearch/legacygeo/query/LegacyGeoShapeQueryProcessor.java

@@ -97,18 +97,12 @@ public class LegacyGeoShapeQueryProcessor {
     }
 
     public static SpatialArgs getArgs(Geometry shape, ShapeRelation relation) {
-        switch (relation) {
+        return switch (relation) {
-            case DISJOINT:
+            case DISJOINT -> new SpatialArgs(SpatialOperation.IsDisjointTo, buildS4J(shape));
-                return new SpatialArgs(SpatialOperation.IsDisjointTo, buildS4J(shape));
+            case INTERSECTS -> new SpatialArgs(SpatialOperation.Intersects, buildS4J(shape));
-            case INTERSECTS:
+            case WITHIN -> new SpatialArgs(SpatialOperation.IsWithin, buildS4J(shape));
-                return new SpatialArgs(SpatialOperation.Intersects, buildS4J(shape));
+            case CONTAINS -> new SpatialArgs(SpatialOperation.Contains, buildS4J(shape));
-            case WITHIN:
+        };
-                return new SpatialArgs(SpatialOperation.IsWithin, buildS4J(shape));
-            case CONTAINS:
-                return new SpatialArgs(SpatialOperation.Contains, buildS4J(shape));
-            default:
-                throw new IllegalArgumentException("invalid relation [" + relation + "]");
-        }
     }
 
     /**

modules/legacy-geo/src/test/java/org/elasticsearch/legacygeo/builders/EnvelopeBuilderTests.java

@@ -35,35 +35,27 @@ public class EnvelopeBuilderTests extends AbstractShapeBuilderTestCase<EnvelopeB
     }
 
     static EnvelopeBuilder mutate(EnvelopeBuilder original) throws IOException {
-        EnvelopeBuilder mutation = copyShape(original);
+        copyShape(original);
         // move one corner to the middle of original
-        switch (randomIntBetween(0, 3)) {
+        return switch (randomIntBetween(0, 3)) {
-            case 0:
+            case 0 -> new EnvelopeBuilder(
-                mutation = new EnvelopeBuilder(
                 new Coordinate(randomDoubleBetween(-180.0, original.bottomRight().x, true), original.topLeft().y),
                 original.bottomRight()
             );
-                break;
+            case 1 -> new EnvelopeBuilder(
-            case 1:
-                mutation = new EnvelopeBuilder(
                 new Coordinate(original.topLeft().x, randomDoubleBetween(original.bottomRight().y, 90.0, true)),
                 original.bottomRight()
             );
-                break;
+            case 2 -> new EnvelopeBuilder(
-            case 2:
-                mutation = new EnvelopeBuilder(
                 original.topLeft(),
                 new Coordinate(randomDoubleBetween(original.topLeft().x, 180.0, true), original.bottomRight().y)
             );
-                break;
+            case 3 -> new EnvelopeBuilder(
-            case 3:
-                mutation = new EnvelopeBuilder(
                 original.topLeft(),
                 new Coordinate(original.bottomRight().x, randomDoubleBetween(-90.0, original.topLeft().y, true))
             );
-                break;
+            default -> copyShape(original);
-        }
+        };
-        return mutation;
     }
 
     static EnvelopeBuilder createRandomShape() {

modules/legacy-geo/src/test/java/org/elasticsearch/legacygeo/builders/GeometryCollectionBuilderTests.java

@@ -20,30 +20,14 @@ public class GeometryCollectionBuilderTests extends AbstractShapeBuilderTestCase
         int shapes = randomIntBetween(0, 8);
         for (int i = 0; i < shapes; i++) {
             switch (randomIntBetween(0, 7)) {
-                case 0:
+                case 0 -> geometryCollection.shape(PointBuilderTests.createRandomShape());
-                    geometryCollection.shape(PointBuilderTests.createRandomShape());
+                case 1 -> geometryCollection.shape(CircleBuilderTests.createRandomShape());
-                    break;
+                case 2 -> geometryCollection.shape(EnvelopeBuilderTests.createRandomShape());
-                case 1:
+                case 3 -> geometryCollection.shape(LineStringBuilderTests.createRandomShape());
-                    geometryCollection.shape(CircleBuilderTests.createRandomShape());
+                case 4 -> geometryCollection.shape(MultiLineStringBuilderTests.createRandomShape());
-                    break;
+                case 5 -> geometryCollection.shape(MultiPolygonBuilderTests.createRandomShape());
-                case 2:
+                case 6 -> geometryCollection.shape(MultiPointBuilderTests.createRandomShape());
-                    geometryCollection.shape(EnvelopeBuilderTests.createRandomShape());
+                case 7 -> geometryCollection.shape(PolygonBuilderTests.createRandomShape());
-                    break;
-                case 3:
-                    geometryCollection.shape(LineStringBuilderTests.createRandomShape());
-                    break;
-                case 4:
-                    geometryCollection.shape(MultiLineStringBuilderTests.createRandomShape());
-                    break;
-                case 5:
-                    geometryCollection.shape(MultiPolygonBuilderTests.createRandomShape());
-                    break;
-                case 6:
-                    geometryCollection.shape(MultiPointBuilderTests.createRandomShape());
-                    break;
-                case 7:
-                    geometryCollection.shape(PolygonBuilderTests.createRandomShape());
-                    break;
             }
         }
         return geometryCollection;
@@ -59,35 +43,19 @@ public class GeometryCollectionBuilderTests extends AbstractShapeBuilderTestCase
         if (mutation.shapes.size() > 0) {
             int shapePosition = randomIntBetween(0, mutation.shapes.size() - 1);
             ShapeBuilder<?, ?, ?> shapeToChange = mutation.shapes.get(shapePosition);
-            switch (shapeToChange.type()) {
+            mutation.shapes.set(shapePosition, switch (shapeToChange.type()) {
-                case POINT:
+                case POINT -> PointBuilderTests.mutate((PointBuilder) shapeToChange);
-                    shapeToChange = PointBuilderTests.mutate((PointBuilder) shapeToChange);
+                case CIRCLE -> CircleBuilderTests.mutate((CircleBuilder) shapeToChange);
-                    break;
+                case ENVELOPE -> EnvelopeBuilderTests.mutate((EnvelopeBuilder) shapeToChange);
-                case CIRCLE:
+                case LINESTRING -> LineStringBuilderTests.mutate((LineStringBuilder) shapeToChange);
-                    shapeToChange = CircleBuilderTests.mutate((CircleBuilder) shapeToChange);
+                case MULTILINESTRING -> MultiLineStringBuilderTests.mutate((MultiLineStringBuilder) shapeToChange);
-                    break;
+                case MULTIPOLYGON -> MultiPolygonBuilderTests.mutate((MultiPolygonBuilder) shapeToChange);
-                case ENVELOPE:
+                case MULTIPOINT -> MultiPointBuilderTests.mutate((MultiPointBuilder) shapeToChange);
-                    shapeToChange = EnvelopeBuilderTests.mutate((EnvelopeBuilder) shapeToChange);
+                case POLYGON -> PolygonBuilderTests.mutate((PolygonBuilder) shapeToChange);
-                    break;
+                case GEOMETRYCOLLECTION -> throw new UnsupportedOperationException(
-                case LINESTRING:
+                    "GeometryCollection should not be nested inside each other"
-                    shapeToChange = LineStringBuilderTests.mutate((LineStringBuilder) shapeToChange);
+                );
-                    break;
+            });
-                case MULTILINESTRING:
-                    shapeToChange = MultiLineStringBuilderTests.mutate((MultiLineStringBuilder) shapeToChange);
-                    break;
-                case MULTIPOLYGON:
-                    shapeToChange = MultiPolygonBuilderTests.mutate((MultiPolygonBuilder) shapeToChange);
-                    break;
-                case MULTIPOINT:
-                    shapeToChange = MultiPointBuilderTests.mutate((MultiPointBuilder) shapeToChange);
-                    break;
-                case POLYGON:
-                    shapeToChange = PolygonBuilderTests.mutate((PolygonBuilder) shapeToChange);
-                    break;
-                case GEOMETRYCOLLECTION:
-                    throw new UnsupportedOperationException("GeometryCollection should not be nested inside each other");
-            }
-            mutation.shapes.set(shapePosition, shapeToChange);
         } else {
             mutation.shape(RandomShapeGenerator.createShape(random()));
         }

modules/mapper-extras/src/main/java/org/elasticsearch/index/mapper/extras/RankFeatureQueryBuilder.java

@@ -290,18 +290,13 @@ public final class RankFeatureQueryBuilder extends AbstractQueryBuilder<RankFeat
 
     private static ScoreFunction readScoreFunction(StreamInput in) throws IOException {
         byte b = in.readByte();
-        switch (b) {
+        return switch (b) {
-            case 0:
+            case 0 -> new ScoreFunction.Log(in);
-                return new ScoreFunction.Log(in);
+            case 1 -> new ScoreFunction.Saturation(in);
-            case 1:
+            case 2 -> new ScoreFunction.Sigmoid(in);
-                return new ScoreFunction.Saturation(in);
+            case 3 -> new ScoreFunction.Linear(in);
-            case 2:
+            default -> throw new IOException("Illegal score function id: " + b);
-                return new ScoreFunction.Sigmoid(in);
+        };
-            case 3:
-                return new ScoreFunction.Linear(in);
-            default:
-                throw new IOException("Illegal score function id: " + b);
-        }
     }
 
     public static final ConstructingObjectParser<RankFeatureQueryBuilder, Void> PARSER = new ConstructingObjectParser<>("feature", args -> {

modules/mapper-extras/src/test/java/org/elasticsearch/index/mapper/extras/ScaledFloatFieldMapperTests.java

@@ -341,17 +341,12 @@ public class ScaledFloatFieldMapperTests extends MapperTestCase {
          * range of valid values.
          */
         double v = randomDoubleBetween(-Float.MAX_VALUE, Float.MAX_VALUE, true);
-        switch (between(0, 3)) {
+        return switch (between(0, 3)) {
-            case 0:
+            case 0 -> v;
-                return v;
+            case 1 -> (float) v;
-            case 1:
+            case 2 -> Double.toString(v);
-                return (float) v;
+            case 3 -> Float.toString((float) v);
-            case 2:
+            default -> throw new IllegalArgumentException();
-                return Double.toString(v);
+        };
-            case 3:
-                return Float.toString((float) v);
-            default:
-                throw new IllegalArgumentException();
-        }
     }
 }

modules/percolator/src/test/java/org/elasticsearch/percolator/PercolatorFieldMapperTests.java

@@ -921,31 +921,29 @@ public class PercolatorFieldMapperTests extends ESSingleNodeTestCase {
             final int randomFrom = randomInt();
             final byte[] encodedFrom;
             switch (encodingType) {
-                case 0:
+                case 0 -> {
                     encodedFrom = new byte[Integer.BYTES];
                     IntPoint.encodeDimension(randomFrom, encodedFrom, 0);
-                    break;
+                }
-                case 1:
+                case 1 -> {
                     encodedFrom = new byte[Long.BYTES];
                     LongPoint.encodeDimension(randomFrom, encodedFrom, 0);
-                    break;
+                }
-                default:
+                default -> throw new AssertionError("unexpected encoding type [" + encodingType + "]");
-                    throw new AssertionError("unexpected encoding type [" + encodingType + "]");
             }
 
             final int randomTo = randomIntBetween(randomFrom, Integer.MAX_VALUE);
             final byte[] encodedTo;
             switch (encodingType) {
-                case 0:
+                case 0 -> {
                     encodedTo = new byte[Integer.BYTES];
                     IntPoint.encodeDimension(randomTo, encodedTo, 0);
-                    break;
+                }
-                case 1:
+                case 1 -> {
                     encodedTo = new byte[Long.BYTES];
                     LongPoint.encodeDimension(randomTo, encodedTo, 0);
-                    break;
+                }
-                default:
+                default -> throw new AssertionError("unexpected encoding type [" + encodingType + "]");
-                    throw new AssertionError("unexpected encoding type [" + encodingType + "]");
             }
 
             String randomFieldName = randomAlphaOfLength(5);
@@ -957,20 +955,19 @@ public class PercolatorFieldMapperTests extends ESSingleNodeTestCase {
             MurmurHash3.hash128(fieldAsBytesRef.bytes, fieldAsBytesRef.offset, fieldAsBytesRef.length, 0, hash);
 
             switch (encodingType) {
-                case 0:
+                case 0 -> {
                     assertEquals(hash.h1, ByteBuffer.wrap(subByteArray(result, 0, 8)).getLong());
                     assertEquals(randomFrom, IntPoint.decodeDimension(subByteArray(result, 12, 4), 0));
                     assertEquals(hash.h1, ByteBuffer.wrap(subByteArray(result, 16, 8)).getLong());
                     assertEquals(randomTo, IntPoint.decodeDimension(subByteArray(result, 28, 4), 0));
-                    break;
+                }
-                case 1:
+                case 1 -> {
                     assertEquals(hash.h1, ByteBuffer.wrap(subByteArray(result, 0, 8)).getLong());
                     assertEquals(randomFrom, LongPoint.decodeDimension(subByteArray(result, 8, 8), 0));
                     assertEquals(hash.h1, ByteBuffer.wrap(subByteArray(result, 16, 8)).getLong());
                     assertEquals(randomTo, LongPoint.decodeDimension(subByteArray(result, 24, 8), 0));
-                    break;
+                }
-                default:
+                default -> throw new AssertionError("unexpected encoding type [" + encodingType + "]");
-                    throw new AssertionError("unexpected encoding type [" + encodingType + "]");
             }
         }
     }

modules/rank-eval/src/test/java/org/elasticsearch/index/rankeval/DiscountedCumulativeGainTests.java

@@ -319,23 +319,19 @@ public class DiscountedCumulativeGainTests extends ESTestCase {
     }
 
     private static DiscountedCumulativeGain mutateTestItem(DiscountedCumulativeGain original) {
-        switch (randomIntBetween(0, 2)) {
+        return switch (randomIntBetween(0, 2)) {
-            case 0:
+            case 0 -> new DiscountedCumulativeGain(original.getNormalize() == false, original.getUnknownDocRating(), original.getK());
-                return new DiscountedCumulativeGain(original.getNormalize() == false, original.getUnknownDocRating(), original.getK());
+            case 1 -> new DiscountedCumulativeGain(
-            case 1:
-                return new DiscountedCumulativeGain(
                 original.getNormalize(),
                 randomValueOtherThan(original.getUnknownDocRating(), () -> randomIntBetween(0, 10)),
                 original.getK()
             );
-            case 2:
+            case 2 -> new DiscountedCumulativeGain(
-                return new DiscountedCumulativeGain(
                 original.getNormalize(),
                 original.getUnknownDocRating(),
                 randomValueOtherThan(original.getK(), () -> randomIntBetween(1, 10))
             );
-            default:
+            default -> throw new IllegalArgumentException("mutation variant not allowed");
-                throw new IllegalArgumentException("mutation variant not allowed");
+        };
-        }
     }
 }

modules/rank-eval/src/test/java/org/elasticsearch/index/rankeval/EvalQueryQualityTests.java

@@ -52,23 +52,16 @@ public class EvalQueryQualityTests extends ESTestCase {
         if (randomBoolean()) {
             int metricDetail = randomIntBetween(0, 2);
             switch (metricDetail) {
-                case 0:
+                case 0 -> evalQueryQuality.setMetricDetails(new PrecisionAtK.Detail(randomIntBetween(0, 1000), randomIntBetween(0, 1000)));
-                    evalQueryQuality.setMetricDetails(new PrecisionAtK.Detail(randomIntBetween(0, 1000), randomIntBetween(0, 1000)));
+                case 1 -> evalQueryQuality.setMetricDetails(new MeanReciprocalRank.Detail(randomIntBetween(0, 1000)));
-                    break;
+                case 2 -> evalQueryQuality.setMetricDetails(
-                case 1:
-                    evalQueryQuality.setMetricDetails(new MeanReciprocalRank.Detail(randomIntBetween(0, 1000)));
-                    break;
-                case 2:
-                    evalQueryQuality.setMetricDetails(
                     new DiscountedCumulativeGain.Detail(
                         randomDoubleBetween(0, 1, true),
                         randomBoolean() ? randomDoubleBetween(0, 1, true) : 0,
                         randomInt()
                     )
                 );
-                    break;
+                default -> throw new IllegalArgumentException("illegal randomized value in test");
-                default:
-                    throw new IllegalArgumentException("illegal randomized value in test");
             }
         }
         evalQueryQuality.addHitsAndRatings(ratedHits);

modules/rank-eval/src/test/java/org/elasticsearch/index/rankeval/ExpectedReciprocalRankTests.java

@@ -196,23 +196,19 @@ public class ExpectedReciprocalRankTests extends ESTestCase {
     }
 
     private static ExpectedReciprocalRank mutateTestItem(ExpectedReciprocalRank original) {
-        switch (randomIntBetween(0, 2)) {
+        return switch (randomIntBetween(0, 2)) {
-            case 0:
+            case 0 -> new ExpectedReciprocalRank(original.getMaxRelevance() + 1, original.getUnknownDocRating(), original.getK());
-                return new ExpectedReciprocalRank(original.getMaxRelevance() + 1, original.getUnknownDocRating(), original.getK());
+            case 1 -> new ExpectedReciprocalRank(
-            case 1:
-                return new ExpectedReciprocalRank(
                 original.getMaxRelevance(),
                 randomValueOtherThan(original.getUnknownDocRating(), () -> randomIntBetween(0, 10)),
                 original.getK()
             );
-            case 2:
+            case 2 -> new ExpectedReciprocalRank(
-                return new ExpectedReciprocalRank(
                 original.getMaxRelevance(),
                 original.getUnknownDocRating(),
                 randomValueOtherThan(original.getK(), () -> randomIntBetween(1, 10))
             );
-            default:
+            default -> throw new IllegalArgumentException("mutation variant not allowed");
-                throw new IllegalArgumentException("mutation variant not allowed");
+        };
-        }
     }
 }

modules/rank-eval/src/test/java/org/elasticsearch/index/rankeval/PrecisionAtKTests.java

@@ -224,32 +224,24 @@ public class PrecisionAtKTests extends ESTestCase {
     }
 
     private static PrecisionAtK mutate(PrecisionAtK original) {
-        PrecisionAtK pAtK;
+        PrecisionAtK pAtK = switch (randomIntBetween(0, 2)) {
-        switch (randomIntBetween(0, 2)) {
+            case 0 -> new PrecisionAtK(
-            case 0:
-                pAtK = new PrecisionAtK(
                 original.getRelevantRatingThreshold(),
                 original.getIgnoreUnlabeled() == false,
                 original.forcedSearchSize().getAsInt()
             );
-                break;
+            case 1 -> new PrecisionAtK(
-            case 1:
-                pAtK = new PrecisionAtK(
                 randomValueOtherThan(original.getRelevantRatingThreshold(), () -> randomIntBetween(0, 10)),
                 original.getIgnoreUnlabeled(),
                 original.forcedSearchSize().getAsInt()
             );
-                break;
+            case 2 -> new PrecisionAtK(
-            case 2:
-                pAtK = new PrecisionAtK(
                 original.getRelevantRatingThreshold(),
                 original.getIgnoreUnlabeled(),
                 original.forcedSearchSize().getAsInt() + 1
             );
-                break;
+            default -> throw new IllegalStateException("The test should only allow three parameters mutated");
-            default:
+        };
-                throw new IllegalStateException("The test should only allow three parameters mutated");
-        }
         return pAtK;
     }
 

modules/rank-eval/src/test/java/org/elasticsearch/index/rankeval/RatedDocumentTests.java

@@ -80,17 +80,10 @@ public class RatedDocumentTests extends ESTestCase {
         String docId = original.getDocID();
 
         switch (randomIntBetween(0, 2)) {
-            case 0:
+            case 0 -> rating = randomValueOtherThan(rating, () -> randomInt());
-                rating = randomValueOtherThan(rating, () -> randomInt());
+            case 1 -> index = randomValueOtherThan(index, () -> randomAlphaOfLength(10));
-                break;
+            case 2 -> docId = randomValueOtherThan(docId, () -> randomAlphaOfLength(10));
-            case 1:
+            default -> throw new IllegalStateException("The test should only allow two parameters mutated");
-                index = randomValueOtherThan(index, () -> randomAlphaOfLength(10));
-                break;
-            case 2:
-                docId = randomValueOtherThan(docId, () -> randomAlphaOfLength(10));
-                break;
-            default:
-                throw new IllegalStateException("The test should only allow two parameters mutated");
         }
         return new RatedDocument(index, docId, rating);
     }

modules/rank-eval/src/test/java/org/elasticsearch/index/rankeval/RatedSearchHitTests.java

@@ -40,14 +40,14 @@ public class RatedSearchHitTests extends ESTestCase {
         OptionalInt rating = original.getRating();
         SearchHit hit = original.getSearchHit();
         switch (randomIntBetween(0, 1)) {
-            case 0:
+            case 0 -> rating = rating.isPresent() ? OptionalInt.of(rating.getAsInt() + 1) : OptionalInt.of(randomInt(5));
-                rating = rating.isPresent() ? OptionalInt.of(rating.getAsInt() + 1) : OptionalInt.of(randomInt(5));
+            case 1 -> hit = new SearchHit(
-                break;
+                hit.docId(),
-            case 1:
+                hit.getId() + randomAlphaOfLength(10),
-                hit = new SearchHit(hit.docId(), hit.getId() + randomAlphaOfLength(10), Collections.emptyMap(), Collections.emptyMap());
+                Collections.emptyMap(),
-                break;
+                Collections.emptyMap()
-            default:
+            );
-                throw new IllegalStateException("The test should only allow two parameters mutated");
+            default -> throw new IllegalStateException("The test should only allow two parameters mutated");
         }
         return new RatedSearchHit(hit, rating);
     }

modules/rank-eval/src/test/java/org/elasticsearch/index/rankeval/RecallAtKTests.java

@@ -202,20 +202,14 @@ public class RecallAtKTests extends ESTestCase {
     }
 
     private static RecallAtK mutate(RecallAtK original) {
-        RecallAtK recallAtK;
+        RecallAtK recallAtK = switch (randomIntBetween(0, 1)) {
-        switch (randomIntBetween(0, 1)) {
+            case 0 -> new RecallAtK(
-            case 0:
-                recallAtK = new RecallAtK(
                 randomValueOtherThan(original.getRelevantRatingThreshold(), () -> randomIntBetween(0, 10)),
                 original.forcedSearchSize().getAsInt()
             );
-                break;
+            case 1 -> new RecallAtK(original.getRelevantRatingThreshold(), original.forcedSearchSize().getAsInt() + 1);
-            case 1:
+            default -> throw new IllegalStateException("The test should only allow two parameters mutated");
-                recallAtK = new RecallAtK(original.getRelevantRatingThreshold(), original.forcedSearchSize().getAsInt() + 1);
+        };
-                break;
-            default:
-                throw new IllegalStateException("The test should only allow two parameters mutated");
-        }
         return recallAtK;
     }
 

modules/reindex/src/main/java/org/elasticsearch/reindex/AbstractAsyncBulkByScrollAction.java

@@ -908,17 +908,20 @@ public abstract class AbstractAsyncBulkByScrollAction<
 
         protected RequestWrapper<?> scriptChangedOpType(RequestWrapper<?> request, OpType oldOpType, OpType newOpType) {
             switch (newOpType) {
-                case NOOP:
+                case NOOP -> {
                     taskWorker.countNoop();
                     return null;
-                case DELETE:
+                }
+                case DELETE -> {
                     RequestWrapper<DeleteRequest> delete = wrap(new DeleteRequest(request.getIndex(), request.getId()));
                     delete.setVersion(request.getVersion());
                     delete.setVersionType(VersionType.INTERNAL);
                     delete.setRouting(request.getRouting());
                     return delete;
-                default:
+                }
-                    throw new IllegalArgumentException("Unsupported operation type change from [" + oldOpType + "] to [" + newOpType + "]");
+                default -> throw new IllegalArgumentException(
+                    "Unsupported operation type change from [" + oldOpType + "] to [" + newOpType + "]"
+                );
             }
         }
 
@@ -946,18 +949,14 @@ public abstract class AbstractAsyncBulkByScrollAction<
 
         public static OpType fromString(String opType) {
             String lowerOpType = opType.toLowerCase(Locale.ROOT);
-            switch (lowerOpType) {
+            return switch (lowerOpType) {
-                case "noop":
+                case "noop" -> OpType.NOOP;
-                    return OpType.NOOP;
+                case "index" -> OpType.INDEX;
-                case "index":
+                case "delete" -> OpType.DELETE;
-                    return OpType.INDEX;
+                default -> throw new IllegalArgumentException(
-                case "delete":
-                    return OpType.DELETE;
-                default:
-                    throw new IllegalArgumentException(
                     "Operation type [" + lowerOpType + "] not allowed, only " + Arrays.toString(values()) + " are allowed"
                 );
-            }
+            };
         }
 
         @Override

modules/reindex/src/main/java/org/elasticsearch/reindex/Reindexer.java

@@ -336,14 +336,9 @@ public class Reindexer {
                 return;
             }
             switch (routingSpec) {
-                case "keep":
+                case "keep" -> super.copyRouting(request, routing);
-                    super.copyRouting(request, routing);
+                case "discard" -> super.copyRouting(request, null);
-                    break;
+                default -> throw new IllegalArgumentException("Unsupported routing command");
-                case "discard":
-                    super.copyRouting(request, null);
-                    break;
-                default:
-                    throw new IllegalArgumentException("Unsupported routing command");
             }
         }
 

modules/reindex/src/test/java/org/elasticsearch/reindex/AsyncBulkByScrollActionTests.java

@@ -308,23 +308,22 @@ public class AsyncBulkByScrollActionTests extends ESTestCase {
                 boolean createdResponse;
                 DocWriteRequest.OpType opType;
                 switch (randomIntBetween(0, 2)) {
-                    case 0:
+                    case 0 -> {
                         createdResponse = true;
                         opType = DocWriteRequest.OpType.CREATE;
                         created++;
-                        break;
+                    }
-                    case 1:
+                    case 1 -> {
                         createdResponse = false;
                         opType = randomFrom(DocWriteRequest.OpType.INDEX, DocWriteRequest.OpType.UPDATE);
                         updated++;
-                        break;
+                    }
-                    case 2:
+                    case 2 -> {
                         createdResponse = false;
                         opType = DocWriteRequest.OpType.DELETE;
                         deleted++;
-                        break;
+                    }
-                    default:
+                    default -> throw new RuntimeException("Bad scenario");
-                        throw new RuntimeException("Bad scenario");
                 }
                 final int seqNo = randomInt(20);
                 final int primaryTerm = randomIntBetween(1, 16);
@@ -1146,17 +1145,20 @@ public class AsyncBulkByScrollActionTests extends ESTestCase {
             int wraps = randomIntBetween(0, 4);
             for (int i = 0; i < wraps; i++) {
                 switch (randomIntBetween(0, 2)) {
-                    case 0:
+                    case 0 -> {
                         e = new SearchPhaseExecutionException("test", "test failure", e, new ShardSearchFailure[0]);
                         continue;
-                    case 1:
+                    }
+                    case 1 -> {
                         e = new ReduceSearchPhaseException("test", "test failure", e, new ShardSearchFailure[0]);
                         continue;
-                    case 2:
+                    }
+                    case 2 -> {
                         e = new ElasticsearchException(e);
                         continue;
                     }
                 }
+            }
             return e;
         }
     }

plugins/repository-azure/src/main/java/org/elasticsearch/repositories/azure/AzureStorageService.java

@@ -107,14 +107,11 @@ public class AzureStorageService {
             return null;
         }
 
-        switch (proxy.type()) {
+        return switch (proxy.type()) {
-            case HTTP:
+            case HTTP -> new ProxyOptions(ProxyOptions.Type.HTTP, (InetSocketAddress) proxy.address());
-                return new ProxyOptions(ProxyOptions.Type.HTTP, (InetSocketAddress) proxy.address());
+            case SOCKS -> new ProxyOptions(ProxyOptions.Type.SOCKS5, (InetSocketAddress) proxy.address());
-            case SOCKS:
+            default -> null;
-                return new ProxyOptions(ProxyOptions.Type.SOCKS5, (InetSocketAddress) proxy.address());
+        };
-            default:
-                return null;
-        }
     }
 
     // non-static, package private for testing
@@ -138,22 +135,11 @@ public class AzureStorageService {
             throw new IllegalArgumentException("Unable to use " + locationMode + " location mode without a secondary location URI");
         }
 
-        final String secondaryHost;
+        final String secondaryHost = switch (locationMode) {
-        switch (locationMode) {
+            case PRIMARY_ONLY, SECONDARY_ONLY -> null;
-            case PRIMARY_ONLY:
+            case PRIMARY_THEN_SECONDARY -> secondaryUri;
-            case SECONDARY_ONLY:
+            case SECONDARY_THEN_PRIMARY -> primaryUri;
-                secondaryHost = null;
+        };
-                break;
-            case PRIMARY_THEN_SECONDARY:
-                secondaryHost = secondaryUri;
-                break;
-            case SECONDARY_THEN_PRIMARY:
-                secondaryHost = primaryUri;
-                break;
-            default:
-                assert false;
-                throw new AssertionError("Impossible to get here");
-        }
 
         // The request retry policy uses seconds as the default time unit, since
         // it's possible to configure a timeout < 1s we should ceil that value