[NL-to-ESQL] autocorrect bad LIKE wildcards (#202464)

## Summary

Part of #198942

Add autocorrect for wrong `LIKE` wildcard.

The LLM can make mistake and use SQL wildcards for LIKE operators (`_`
instead of `?` and `%` instead of `*`)


Examples

**generated**
```
FROM logs | WHERE message LIKE "a%" AND TO_UPPER(level) LIKE "err%" | WHERE foo LIKE "ba_"
```
**corrected**
```
FROM logs | WHERE message LIKE "a*" AND TO_UPPER(level) LIKE "err*" | WHERE foo LIKE "ba?"
```

---------

Co-authored-by: kibanamachine <[email protected]>

x-pack/plugins/inference/common/tasks/nl_to_esql/ast/corrections/index.ts

@@ -7,12 +7,14 @@
 
 import type { ESQLAstQueryExpression } from '@kbn/esql-ast';
 import type { QueryCorrection } from './types';
-import { applyTimespanLiteralsCorrections } from './timespan_literals';
+import { correctTimespanLiterals } from './timespan_literals';
+import { correctLikeWildcards } from './like';
 
 export type { QueryCorrection } from './types';
 
 export const correctAll = (query: ESQLAstQueryExpression): QueryCorrection[] => {
   const corrections: QueryCorrection[] = [];
-  corrections.push(...applyTimespanLiteralsCorrections(query));
+  corrections.push(...correctTimespanLiterals(query));
+  corrections.push(...correctLikeWildcards(query));
   return corrections;
 };

x-pack/plugins/inference/common/tasks/nl_to_esql/ast/corrections/like.test.ts

@@ -0,0 +1,59 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0; you may not use this file except in compliance with the Elastic License
+ * 2.0.
+ */
+
+import { parse, BasicPrettyPrinter } from '@kbn/esql-ast';
+import { correctLikeWildcards } from './like';
+
+describe('correctLikeWildcards', () => {
+  it('replaces badly used "_" wildcard', () => {
+    const query = 'FROM logs | WHERE message LIKE "ba_"';
+    const { root } = parse(query);
+    correctLikeWildcards(root);
+
+    const output = BasicPrettyPrinter.print(root);
+    expect(output).toEqual('FROM logs | WHERE message LIKE "ba?"');
+  });
+
+  it('replaces badly used "%" wildcard', () => {
+    const query = 'FROM logs | WHERE message LIKE "b%"';
+    const { root } = parse(query);
+    correctLikeWildcards(root);
+
+    const output = BasicPrettyPrinter.print(root);
+    expect(output).toEqual('FROM logs | WHERE message LIKE "b*"');
+  });
+
+  it('replaces multiple bad wildcards', () => {
+    const query = 'FROM logs | WHERE message LIKE "a__t%"';
+    const { root } = parse(query);
+    correctLikeWildcards(root);
+
+    const output = BasicPrettyPrinter.print(root);
+    expect(output).toEqual('FROM logs | WHERE message LIKE "a??t*"');
+  });
+
+  it('replaces bad wildcards in multiple commands and functions', () => {
+    const query =
+      'FROM logs | WHERE message LIKE "a%" AND TO_UPPER(level) LIKE "err%" | WHERE foo LIKE "ba_"';
+    const { root } = parse(query);
+    correctLikeWildcards(root);
+
+    const output = BasicPrettyPrinter.print(root);
+    expect(output).toEqual(
+      'FROM logs | WHERE message LIKE "a*" AND TO_UPPER(level) LIKE "err*" | WHERE foo LIKE "ba?"'
+    );
+  });
+
+  it('does not replace escaped characters', () => {
+    const query = 'FROM logs | WHERE message LIKE "ba\\\\_"';
+    const { root } = parse(query);
+    correctLikeWildcards(root);
+
+    const output = BasicPrettyPrinter.print(root);
+    expect(output).toEqual('FROM logs | WHERE message LIKE "ba\\\\_"');
+  });
+});

x-pack/plugins/inference/common/tasks/nl_to_esql/ast/corrections/like.ts

@@ -0,0 +1,59 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0; you may not use this file except in compliance with the Elastic License
+ * 2.0.
+ */
+
+import { Walker, type ESQLAstQueryExpression } from '@kbn/esql-ast';
+import { isLikeOperatorNode, isStringLiteralNode } from '../typeguards';
+import type { ESQLLikeOperator, ESQLStringLiteral } from '../types';
+import type { QueryCorrection } from './types';
+
+/**
+ * Correct wrong LIKE wildcard mistakes.
+ * The LLM can make mistake and use SQL wildcards for LIKE operators.
+ *
+ * E.g.
+ * `column LIKE "ba_"` => `column LIKE "ba?"`
+ * `column LIKE "ba%"` => `column LIKE "ba*"`
+ */
+export const correctLikeWildcards = (query: ESQLAstQueryExpression): QueryCorrection[] => {
+  const corrections: QueryCorrection[] = [];
+
+  Walker.walk(query, {
+    visitFunction: (node) => {
+      if (isLikeOperatorNode(node)) {
+        corrections.push(...checkLikeNode(node));
+      }
+    },
+  });
+
+  return corrections;
+};
+
+function checkLikeNode(node: ESQLLikeOperator): QueryCorrection[] {
+  if (node.args.length !== 2 || !isStringLiteralNode(node.args[1])) {
+    return [];
+  }
+  const likeExpression = node.args[1] as ESQLStringLiteral;
+
+  const initialValue = likeExpression.value;
+
+  likeExpression.value = likeExpression.value
+    .replaceAll(/(?<!\\)%/g, '*')
+    .replaceAll(/(?<!\\)_/g, '?');
+
+  if (likeExpression.value !== initialValue) {
+    likeExpression.name = likeExpression.value;
+
+    const correction: QueryCorrection = {
+      type: 'wrong_like_wildcard',
+      node,
+      description: `Replaced wrong like wildcard in LIKE operator at position ${node.location.min}`,
+    };
+    return [correction];
+  }
+
+  return [];
+}

x-pack/plugins/inference/common/tasks/nl_to_esql/ast/corrections/timespan_literals.test.ts

@@ -6,15 +6,15 @@
  */
 
 import { parse, BasicPrettyPrinter } from '@kbn/esql-ast';
-import { applyTimespanLiteralsCorrections } from './timespan_literals';
+import { correctTimespanLiterals } from './timespan_literals';
 
-describe('getTimespanLiteralsCorrections', () => {
+describe('correctTimespanLiterals', () => {
   describe('with DATE_TRUNC', () => {
     it('replaces a timespan with a proper timespan literal', () => {
       const query = 'FROM logs | EVAL truncated = DATE_TRUNC("1 year", date)';
       const { root } = parse(query);
 
-      applyTimespanLiteralsCorrections(root);
+      correctTimespanLiterals(root);
 
       const output = BasicPrettyPrinter.print(root);
 
@@ -27,7 +27,7 @@ describe('getTimespanLiteralsCorrections', () => {
       const query = 'FROM logs | EVAL truncated = DATE_TRUNC("month", date)';
       const { root } = parse(query);
 
-      applyTimespanLiteralsCorrections(root);
+      correctTimespanLiterals(root);
 
       const output = BasicPrettyPrinter.print(root);
 
@@ -40,7 +40,7 @@ describe('getTimespanLiteralsCorrections', () => {
       const query = 'FROM logs | EVAL truncated = DATE_TRUNC("1 YEAR", date)';
       const { root } = parse(query);
 
-      applyTimespanLiteralsCorrections(root);
+      correctTimespanLiterals(root);
 
       const output = BasicPrettyPrinter.print(root);
 
@@ -53,7 +53,7 @@ describe('getTimespanLiteralsCorrections', () => {
       const query = 'FROM logs | EVAL truncated = DATE_TRUNC("1 year", date)';
       const { root } = parse(query);
 
-      const corrections = applyTimespanLiteralsCorrections(root);
+      const corrections = correctTimespanLiterals(root);
 
       expect(corrections).toHaveLength(1);
       expect(corrections[0]).toEqual({
@@ -70,7 +70,7 @@ describe('getTimespanLiteralsCorrections', () => {
       const query = 'FROM logs | STATS hires = COUNT(*) BY week = BUCKET(hire_date, "1 week")';
       const { root } = parse(query);
 
-      applyTimespanLiteralsCorrections(root);
+      correctTimespanLiterals(root);
 
       const output = BasicPrettyPrinter.print(root);
 
@@ -83,7 +83,7 @@ describe('getTimespanLiteralsCorrections', () => {
       const query = 'FROM logs | STATS hires = COUNT(*) BY hour = BUCKET(hire_date, "hour")';
       const { root } = parse(query);
 
-      applyTimespanLiteralsCorrections(root);
+      correctTimespanLiterals(root);
 
       const output = BasicPrettyPrinter.print(root);
 
@@ -96,7 +96,7 @@ describe('getTimespanLiteralsCorrections', () => {
       const query = 'FROM logs | STATS hires = COUNT(*) BY week = BUCKET(hire_date, "1 WEEK")';
       const { root } = parse(query);
 
-      applyTimespanLiteralsCorrections(root);
+      correctTimespanLiterals(root);
 
       const output = BasicPrettyPrinter.print(root);
 
@@ -109,7 +109,7 @@ describe('getTimespanLiteralsCorrections', () => {
       const query = 'FROM logs | STATS hires = COUNT(*) BY hour = BUCKET(hire_date, "hour")';
       const { root } = parse(query);
 
-      const corrections = applyTimespanLiteralsCorrections(root);
+      const corrections = correctTimespanLiterals(root);
 
       expect(corrections).toHaveLength(1);
       expect(corrections[0]).toEqual({
@@ -129,7 +129,7 @@ describe('getTimespanLiteralsCorrections', () => {
     | STATS hires = COUNT(*) BY hour = BUCKET(hire_date, "3 hour")`;
       const { root } = parse(query);
 
-      applyTimespanLiteralsCorrections(root);
+      correctTimespanLiterals(root);
 
       const output = BasicPrettyPrinter.print(root, { multiline: true, pipeTab: '' });
 

x-pack/plugins/inference/common/tasks/nl_to_esql/ast/corrections/timespan_literals.ts

@@ -19,9 +19,7 @@ import { QueryCorrection } from './types';
  * `BUCKET(@timestamp, "1 week")` => `BUCKET(@timestamp, 1 week)`
  *
  */
-export const applyTimespanLiteralsCorrections = (
-  query: ESQLAstQueryExpression
-): QueryCorrection[] => {
+export const correctTimespanLiterals = (query: ESQLAstQueryExpression): QueryCorrection[] => {
   const corrections: QueryCorrection[] = [];
 
   Walker.walk(query, {

x-pack/plugins/inference/common/tasks/nl_to_esql/ast/typeguards.ts

@@ -5,8 +5,19 @@
  * 2.0.
  */
 
-import type { ESQLSingleAstItem, ESQLAstItem, ESQLFunction, ESQLLiteral } from '@kbn/esql-ast';
-import type { ESQLStringLiteral, ESQLDateTruncFunction, ESQLBucketFunction } from './types';
+import type {
+  ESQLSingleAstItem,
+  ESQLAstItem,
+  ESQLFunction,
+  ESQLLiteral,
+  ESQLColumn,
+} from '@kbn/esql-ast';
+import type {
+  ESQLStringLiteral,
+  ESQLDateTruncFunction,
+  ESQLBucketFunction,
+  ESQLLikeOperator,
+} from './types';
 
 export function isSingleItem(item: ESQLAstItem): item is ESQLSingleAstItem {
   return Object.hasOwn(item, 'type');
@@ -16,6 +27,10 @@ export function isFunctionNode(node: ESQLAstItem): node is ESQLFunction {
   return isSingleItem(node) && node.type === 'function';
 }
 
+export function isColumnNode(node: ESQLAstItem): node is ESQLColumn {
+  return isSingleItem(node) && node.type === 'column';
+}
+
 export function isLiteralNode(node: ESQLAstItem): node is ESQLLiteral {
   return isSingleItem(node) && node.type === 'literal';
 }
@@ -31,3 +46,7 @@ export function isDateTruncFunctionNode(node: ESQLAstItem): node is ESQLDateTrun
 export function isBucketFunctionNode(node: ESQLAstItem): node is ESQLBucketFunction {
   return isFunctionNode(node) && node.subtype === 'variadic-call' && node.name === 'bucket';
 }
+
+export function isLikeOperatorNode(node: ESQLAstItem): node is ESQLLikeOperator {
+  return isFunctionNode(node) && node.subtype === 'binary-expression' && node.name === 'like';
+}

x-pack/plugins/inference/common/tasks/nl_to_esql/ast/types.ts

@@ -12,6 +12,11 @@ import { ESQLFunction, ESQLLiteral } from '@kbn/esql-ast';
  */
 export type ESQLDateTruncFunction = ESQLFunction<'variadic-call', 'date_trunc'>;
 
+/**
+ * represents a LIKE function node.
+ */
+export type ESQLLikeOperator = ESQLFunction<'binary-expression', 'like'>;
+
 /**
  * represents a BUCKET function node.
  */