+ * Consider this example: + *
{@code
+ * switch (between(0, 3)) {
+ * case 0 -> name += randomAlphaOfLength(5);
+ * case 1 -> requiredSize += between(1, 100);
+ * case 2 -> minDocCount += between(1, 100);
+ * case 3 -> subsetSize += between(1, 100);
+ * case 4 -> supersetSize += between(1, 100);
+ * }
+ * }
+ * The "4" case is an error, because it can never execute.
+ */
+@StatelessCheck
+public class SwitchBetweenCheck extends AbstractCheck {
+
+ public static final String SWITCH_RANDOM_INT_MSG_KEY = "forbidden.switch.randomInt";
+ public static final String SWITCH_BETWEEN_MSG_KEY = "forbidden.switch.between";
+
+ @Override
+ public int[] getDefaultTokens() {
+ return getRequiredTokens();
+ }
+
+ @Override
+ public int[] getAcceptableTokens() {
+ return getRequiredTokens();
+ }
+
+ @Override
+ public int[] getRequiredTokens() {
+ return new int[] { TokenTypes.LITERAL_SWITCH };
+ }
+
+ @Override
+ public void visitToken(DetailAST ast) {
+ checkSwitchBetween(ast);
+ }
+
+ private void checkSwitchBetween(DetailAST ast) {
+ // First dig out the switch expression
+ final DetailAST switchExprAst = ast.findFirstToken(TokenTypes.EXPR);
+ if (switchExprAst == null) {
+ return;
+ }
+
+ // Check if it's a method call
+ final DetailAST methodCallAst = switchExprAst.getFirstChild();
+ if (methodCallAst.getType() != TokenTypes.METHOD_CALL) {
+ return;
+ }
+
+ // And check if the method call is a `between` or `randomIntBetween` call
+ final DetailAST methodIdentAst = methodCallAst.findFirstToken(TokenTypes.IDENT);
+ if (methodIdentAst == null) {
+ return;
+ }
+ final String switchMethodName = methodIdentAst.getText();
+ switch (switchMethodName) {
+ case "between":
+ case "randomIntBetween":
+ case "randomInt":
+ // these are ok
+ break;
+ default:
+ return;
+ }
+
+ // The method name is good, so dig out the arguments to the method. We only handle simple,
+ // integer literal arguments
+ final DetailAST argListAst = methodCallAst.findFirstToken(TokenTypes.ELIST);
+ int min;
+ int max;
+ if (switchMethodName.equals("randomInt")) {
+ if (argListAst.getChildCount() != 1) { // 1 arg
+ return;
+ }
+
+ try {
+ // Get first or last child, which is an EXPR, then get the argument itself
+ final String maxStr = argListAst.getLastChild().getFirstChild().getText();
+ min = 0;
+ max = Integer.parseInt(maxStr);
+ } catch (NumberFormatException e) {
+ return;
+ }
+ } else {
+ if (argListAst.getChildCount() != 3) { // 2 args + COMMA
+ return;
+ }
+
+ try {
+ // Get first or last child, which is an EXPR, then get the argument itself
+ final String minStr = argListAst.getFirstChild().getFirstChild().getText();
+ final String maxStr = argListAst.getLastChild().getFirstChild().getText();
+ min = Integer.parseInt(minStr);
+ max = Integer.parseInt(maxStr);
+ } catch (NumberFormatException e) {
+ return;
+ }
+ }
+
+ // Now check all the cases of the switch and look for values outside the possible range.
+ // We ignore anything that doesn't parse as an integer, so it's possible we could miss
+ // some cases.
+ for (DetailAST caseAst = ast.getFirstChild(); caseAst != null; caseAst = caseAst.getNextSibling()) {
+ if (caseAst.getType() != TokenTypes.CASE_GROUP && caseAst.getType() != TokenTypes.SWITCH_RULE) {
+ continue;
+ }
+
+ final DetailAST literalCaseAst = caseAst.getFirstChild();
+ if (literalCaseAst.getType() == TokenTypes.LITERAL_DEFAULT) {
+ continue;
+ }
+
+ final DetailAST exprAst = literalCaseAst.getFirstChild();
+ if (exprAst.getType() != TokenTypes.EXPR) {
+ continue;
+ }
+
+ try {
+ int value = Integer.parseInt(exprAst.getFirstChild().getText());
+ if (value < min || value > max) {
+ if (switchMethodName.equals("randomInt")) {
+ log(caseAst, SWITCH_RANDOM_INT_MSG_KEY, value, switchMethodName, max);
+ } else {
+ log(caseAst, SWITCH_BETWEEN_MSG_KEY, value, switchMethodName, min, max);
+ }
+ }
+ } catch (NumberFormatException e) {
+ // Ignore
+ }
+ }
+ }
+}
diff --git a/build-tools-internal/src/main/resources/checkstyle.xml b/build-tools-internal/src/main/resources/checkstyle.xml
index 82293ec8b147..bb4d6f448c6e 100644
--- a/build-tools-internal/src/main/resources/checkstyle.xml
+++ b/build-tools-internal/src/main/resources/checkstyle.xml
@@ -140,6 +140,15 @@
value="''{0}'' format specifier is unsafe inside ''.formatted'' calls, as it uses the default locale. Use ''String.format'' for numeric formatting with ''Locale.ROOT'' instead." />
+