[ES|QL] simplify signature definition (removes infiniteParams) (#177628)

## Summary

Close https://github.com/elastic/kibana/issues/177117


### Checklist

Delete any items that are not applicable to this PR.


- [ ] [Unit or functional
tests](https://www.elastic.co/guide/en/kibana/master/development-tests.html)
were updated or added to match the most common scenarios

---------

Co-authored-by: Kibana Machine <42973632+kibanamachine@users.noreply.github.com>

packages/kbn-monaco/src/esql/lib/ast/autocomplete/autocomplete.ts

@@ -425,9 +425,6 @@ function isFunctionArgComplete(
   }
   const cleanedArgs = removeMarkerArgFromArgsList(arg)!.args;
   const argLengthCheck = fnDefinition.signatures.some((def) => {
-    if (def.infiniteParams && cleanedArgs.length > 0) {
-      return true;
-    }
     if (def.minParams && cleanedArgs.length >= def.minParams) {
       return true;
     }
@@ -444,9 +441,6 @@ function isFunctionArgComplete(
   }
   const hasCorrectTypes = fnDefinition.signatures.some((def) => {
     return arg.args.every((a, index) => {
-      if (def.infiniteParams) {
-        return true;
-      }
       return def.params[index].type === extractFinalTypeFromArg(a, references);
     });
   });
@@ -1087,7 +1081,7 @@ async function getFunctionArgsSuggestions(
     if (signature.params.length > argIndex) {
       return signature.params[argIndex].type;
     }
-    if (signature.infiniteParams || signature.minParams) {
+    if (signature.minParams) {
       return signature.params[signature.params.length - 1].type;
     }
     return [];

packages/kbn-monaco/src/esql/lib/ast/definitions/functions.ts

@@ -677,7 +677,7 @@ export const evalFunctionsDefinitions: FunctionDefinition[] = [
     signatures: [
       {
         params: [{ name: 'field', type: 'any' }],
-        infiniteParams: true,
+        minParams: 1,
         returnType: 'any',
         examples: [`ROW a=null, b="b" | EVAL COALESCE(a, b)`],
       },
@@ -730,7 +730,7 @@ export const evalFunctionsDefinitions: FunctionDefinition[] = [
     signatures: [
       {
         params: [{ name: 'field', type: 'any' }],
-        infiniteParams: true,
+        minParams: 1,
         returnType: 'any',
         examples: [`ROW a = 10, b = 20 | EVAL g = GREATEST(a, b)`],
       },
@@ -744,7 +744,7 @@ export const evalFunctionsDefinitions: FunctionDefinition[] = [
     signatures: [
       {
         params: [{ name: 'first', type: 'any' }],
-        infiniteParams: true,
+        minParams: 1,
         returnType: 'any',
         examples: ['from index | eval l = least(a, b)'],
       },

packages/kbn-monaco/src/esql/lib/ast/definitions/helpers.ts

@@ -8,25 +8,26 @@
 
 import { CommandDefinition, FunctionDefinition } from './types';
 
+/**
+ * Given a function definition, this function will return a list of function signatures
+ *
+ * If withTypes is true, the function will return a formal function definition with all arguments typed.
+ * This is used when generating the function signature for the monaco editor. If withTypes is false, you get
+ * an "injectable" version of the signature to be used to generate test cases.
+ */
 export function getFunctionSignatures(
   { name, signatures }: FunctionDefinition,
   { withTypes }: { withTypes: boolean } = { withTypes: true }
 ) {
-  return signatures.map(({ params, returnType, infiniteParams, minParams, examples }) => {
+  return signatures.map(({ params, returnType, minParams, examples }) => {
     // for functions with a minimum number of args, repeat the last arg multiple times
     // just make sure to compute the right number of args to add
     const minParamsToAdd = Math.max((minParams || 0) - params.length, 0);
-    const hasMoreOptionalArgs = !!infiniteParams || !!minParams;
     const extraArg = Array(minParamsToAdd || 1).fill(params[Math.max(params.length - 1, 0)]);
     return {
       declaration: `${name}(${params
         .map((arg) => printArguments(arg, withTypes))
-        .join(', ')}${handleAdditionalArgs(
-        minParamsToAdd > 0,
-        extraArg,
-        withTypes,
-        false
-      )}${handleAdditionalArgs(hasMoreOptionalArgs, extraArg, withTypes)})${
+        .join(', ')}${handleAdditionalArgs(minParamsToAdd > 0, extraArg, withTypes)})${
         withTypes ? `: ${returnType}` : ''
       }`,
       examples,
@@ -42,13 +43,12 @@ function handleAdditionalArgs(
     optional?: boolean;
     reference?: string;
   }>,
-  withTypes: boolean,
-  optionalArg: boolean = true
+  withTypes: boolean
 ) {
   return criteria
-    ? `${withTypes && optionalArg ? ' ,[... ' : ', '}${additionalArgs
+    ? `${withTypes ? ' ,[... ' : ', '}${additionalArgs
         .map((arg) => printArguments(arg, withTypes))
-        .join(', ')}${withTypes && optionalArg ? ']' : ''}`
+        .join(', ')}${withTypes ? ']' : ''}`
     : '';
 }
 

packages/kbn-monaco/src/esql/lib/ast/definitions/types.ts

@@ -25,7 +25,6 @@ export interface FunctionDefinition {
       supportsWildcard?: boolean;
       literalOnly?: boolean;
     }>;
-    infiniteParams?: boolean;
     minParams?: number;
     returnType: string;
     examples?: string[];

packages/kbn-monaco/src/esql/lib/ast/validation/esql_validation_meta_tests.json

@@ -519,11 +519,11 @@
       "error": false
     },
     {
-      "query": "row var = case(true, \"a\", \"a\", \"a\")",
+      "query": "row var = case(true, \"a\", \"a\")",
       "error": false
     },
     {
-      "query": "row case(true, \"a\", \"a\", \"a\")",
+      "query": "row case(true, \"a\", \"a\")",
       "error": false
     },
     {
@@ -543,19 +543,19 @@
       "error": true
     },
     {
-      "query": "row var = cidr_match(to_ip(\"127.0.0.1\"), \"a\", \"a\")",
+      "query": "row var = cidr_match(to_ip(\"127.0.0.1\"), \"a\")",
       "error": false
     },
     {
-      "query": "row cidr_match(to_ip(\"127.0.0.1\"), \"a\", \"a\")",
+      "query": "row cidr_match(to_ip(\"127.0.0.1\"), \"a\")",
       "error": false
     },
     {
-      "query": "row var = cidr_match(to_ip(\"a\"), to_string(\"a\"), to_string(\"a\"))",
+      "query": "row var = cidr_match(to_ip(\"a\"), to_string(\"a\"))",
       "error": false
     },
     {
-      "query": "row var = cidr_match(\"a\", 5, 5)",
+      "query": "row var = cidr_match(\"a\", 5)",
       "error": true
     },
     {
@@ -567,19 +567,19 @@
       "error": false
     },
     {
-      "query": "row var = concat(\"a\", \"a\", \"a\")",
+      "query": "row var = concat(\"a\", \"a\")",
       "error": false
     },
     {
-      "query": "row concat(\"a\", \"a\", \"a\")",
+      "query": "row concat(\"a\", \"a\")",
       "error": false
     },
     {
-      "query": "row var = concat(to_string(\"a\"), to_string(\"a\"), to_string(\"a\"))",
+      "query": "row var = concat(to_string(\"a\"), to_string(\"a\"))",
       "error": false
     },
     {
-      "query": "row var = concat(5, 5, 5)",
+      "query": "row var = concat(5, 5)",
       "error": true
     },
     {
@@ -3607,11 +3607,11 @@
       "error": true
     },
     {
-      "query": "from a_index | where length(concat(stringField, stringField, stringField)) > 0",
+      "query": "from a_index | where length(concat(stringField, stringField)) > 0",
       "error": false
     },
     {
-      "query": "from a_index | where length(concat(numberField, numberField, numberField)) > 0",
+      "query": "from a_index | where length(concat(numberField, numberField)) > 0",
       "error": true
     },
     {
@@ -4815,11 +4815,11 @@
       "error": true
     },
     {
-      "query": "from a_index | eval var = case(booleanField, stringField, stringField, stringField)",
+      "query": "from a_index | eval var = case(booleanField, stringField, stringField)",
       "error": false
     },
     {
-      "query": "from a_index | eval case(booleanField, stringField, stringField, stringField)",
+      "query": "from a_index | eval case(booleanField, stringField, stringField)",
       "error": false
     },
     {
@@ -4847,19 +4847,19 @@
       "error": true
     },
     {
-      "query": "from a_index | eval var = cidr_match(ipField, stringField, stringField)",
+      "query": "from a_index | eval var = cidr_match(ipField, stringField)",
       "error": false
     },
     {
-      "query": "from a_index | eval cidr_match(ipField, stringField, stringField)",
+      "query": "from a_index | eval cidr_match(ipField, stringField)",
       "error": false
     },
     {
-      "query": "from a_index | eval var = cidr_match(to_ip(stringField), to_string(stringField), to_string(stringField))",
+      "query": "from a_index | eval var = cidr_match(to_ip(stringField), to_string(stringField))",
       "error": false
     },
     {
-      "query": "from a_index | eval cidr_match(stringField, numberField, numberField)",
+      "query": "from a_index | eval cidr_match(stringField, numberField)",
       "error": true
     },
     {
@@ -4871,23 +4871,19 @@
       "error": false
     },
     {
-      "query": "from a_index | eval var = coalesce(*)",
-      "error": true
-    },
-    {
-      "query": "from a_index | eval var = concat(stringField, stringField, stringField)",
+      "query": "from a_index | eval var = concat(stringField, stringField)",
       "error": false
     },
     {
-      "query": "from a_index | eval concat(stringField, stringField, stringField)",
+      "query": "from a_index | eval concat(stringField, stringField)",
       "error": false
     },
     {
-      "query": "from a_index | eval var = concat(to_string(stringField), to_string(stringField), to_string(stringField))",
+      "query": "from a_index | eval var = concat(to_string(stringField), to_string(stringField))",
       "error": false
     },
     {
-      "query": "from a_index | eval concat(numberField, numberField, numberField)",
+      "query": "from a_index | eval concat(numberField, numberField)",
       "error": true
     },
     {
@@ -5090,10 +5086,6 @@
       "query": "from a_index | eval greatest(stringField)",
       "error": false
     },
-    {
-      "query": "from a_index | eval var = greatest(*)",
-      "error": true
-    },
     {
       "query": "from a_index | eval var = least(stringField)",
       "error": false
@@ -5102,10 +5094,6 @@
       "query": "from a_index | eval least(stringField)",
       "error": false
     },
-    {
-      "query": "from a_index | eval var = least(*)",
-      "error": true
-    },
     {
       "query": "from a_index | eval var = left(stringField, numberField)",
       "error": false

packages/kbn-monaco/src/esql/lib/ast/validation/validation.test.ts

@@ -514,7 +514,7 @@ describe('validation logic', () => {
     }
 
     for (const { name, alias, signatures, ...defRest } of evalFunctionsDefinitions) {
-      for (const { params, infiniteParams, ...signRest } of signatures) {
+      for (const { params, ...signRest } of signatures) {
         const fieldMapping = getFieldMapping(params);
         const signatureStringCorrect = tweakSignatureForRowCommand(
           getFunctionSignatures(
@@ -1307,7 +1307,7 @@ describe('validation logic', () => {
     }
 
     for (const { name, alias, signatures, ...defRest } of evalFunctionsDefinitions) {
-      for (const { params, infiniteParams, ...signRest } of signatures) {
+      for (const { params, ...signRest } of signatures) {
         const fieldMapping = getFieldMapping(params);
         testErrorsAndWarnings(
           `from a_index | eval var = ${
@@ -1414,7 +1414,7 @@ describe('validation logic', () => {
             expectedErrors
           );
 
-          if (!infiniteParams && !signRest.minParams) {
+          if (!signRest.minParams) {
             // test that additional args are spotted
             const fieldMappingWithOneExtraArg = getFieldMapping(params).concat({
               name: 'extraArg',
@@ -1835,7 +1835,7 @@ describe('validation logic', () => {
     ]);
 
     for (const { name, alias, signatures, ...defRest } of statsAggregationFunctionDefinitions) {
-      for (const { params, infiniteParams, ...signRest } of signatures) {
+      for (const { params, ...signRest } of signatures) {
         const fieldMapping = getFieldMapping(params);
 
         const correctSignature = getFunctionSignatures(

packages/kbn-monaco/src/esql/lib/ast/validation/validation.ts

@@ -255,9 +255,6 @@ function extractCompatibleSignaturesForFunction(
   astFunction: ESQLFunction
 ) {
   return fnDef.signatures.filter((def) => {
-    if (def.infiniteParams) {
-      return astFunction.args.length > 0;
-    }
     if (def.minParams) {
       return astFunction.args.length >= def.minParams;
     }