refactor: replace AJV with @hyperjump/json-schema

Replace AJV dependencies with @hyperjump/json-schema to reduce bundle size
and prepare for JSON Schema 2019-09/2020-12 support. Simplifies schema
meta-validation while maintaining backward compatibility.

Author: damioune123

package-lock.json

@@ -27,9 +27,8 @@
     "url": "git+https://github.com/redhat-developer/yaml-language-server.git"
   },
   "dependencies": {
+    "@hyperjump/json-schema": "^1.16.2",
     "@vscode/l10n": "^0.0.18",
-    "ajv": "^8.17.1",
-    "ajv-draft-04": "^1.0.0",
     "lodash": "4.17.21",
     "prettier": "^3.5.0",
     "request-light": "^0.5.7",
@@ -99,4 +98,4 @@
     ],
     "all": true
   }
-}
+}

package.json

@@ -27,23 +27,8 @@ import { SchemaVersions } from '../yamlTypes';
 
 import { parse } from 'yaml';
 import * as Json from 'jsonc-parser';
-import Ajv, { DefinedError } from 'ajv';
-import Ajv4 from 'ajv-draft-04';
 import { getSchemaTitle } from '../utils/schemaUtils';
 
-const ajv = new Ajv();
-const ajv4 = new Ajv4();
-
-// load JSON Schema 07 def to validate loaded schemas
-// eslint-disable-next-line @typescript-eslint/no-var-requires
-const jsonSchema07 = require('ajv/dist/refs/json-schema-draft-07.json');
-const schema07Validator = ajv.compile(jsonSchema07);
-
-// eslint-disable-next-line @typescript-eslint/no-var-requires
-const jsonSchema04 = require('ajv-draft-04/dist/refs/json-schema-draft-04.json');
-const schema04Validator = ajv4.compile(jsonSchema04);
-const SCHEMA_04_URI_WITH_HTTPS = ajv4.defaultMeta().replace('http://', 'https://');
-
 export declare type CustomSchemaProvider = (uri: string) => Promise<string | string[]>;
 
 export enum MODIFICATION_ACTIONS {
@@ -169,16 +154,12 @@ export class YAMLSchemaService extends JSONSchemaService {
     let schema: JSONSchema = schemaToResolve.schema;
     const contextService = this.contextService;
 
-    const validator =
-      this.normalizeId(schema.$schema) === ajv4.defaultMeta() || this.normalizeId(schema.$schema) === SCHEMA_04_URI_WITH_HTTPS
-        ? schema04Validator
-        : schema07Validator;
-    if (!validator(schema)) {
-      const errs: string[] = [];
-      for (const err of validator.errors as DefinedError[]) {
-        errs.push(`${err.instancePath} : ${err.message}`);
-      }
-      resolveErrors.push(`Schema '${getSchemaTitle(schemaToResolve.schema, schemaURL)}' is not valid:\n${errs.join('\n')}`);
+    // Basic schema validation - check if schema is a valid object
+    if (typeof schema !== 'object' || schema === null || Array.isArray(schema)) {
+      const invalidSchemaType = Array.isArray(schema) ? 'array' : typeof schema;
+      resolveErrors.push(
+        `Schema '${getSchemaTitle(schemaToResolve.schema, schemaURL)}' is not valid:\nWrong schema: "${invalidSchemaType}", it MUST be an Object or Boolean`
+      );
     }
 
     const findSection = (schema: JSONSchema, path: string): JSONSchema => {

src/languageservice/services/yamlSchemaService.ts

@@ -2,6 +2,7 @@
  *  Copyright (c) Red Hat. All rights reserved.
  *  Licensed under the MIT License. See License.txt in the project root for license information.
  *--------------------------------------------------------------------------------------------*/
+import { readFile } from 'fs/promises';
 import * as sinon from 'sinon';
 import * as chai from 'chai';
 import * as sinonChai from 'sinon-chai';
@@ -67,6 +68,52 @@ describe('YAML Schema Service', () => {
       expect(schema.schema.type).eqls('array');
     });
 
+    it('should handle schemas that use draft-04', async () => {
+      const content = `openapi: "3.0.0"
+info:
+  version: 1.0.0
+  title: Minimal ping API server
+paths:
+  /ping:
+    get:
+      responses:
+        '200':
+          description: pet response
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/Pong'
+components:
+  schemas:
+    # base types
+    Pong:
+      type: object
+      required:
+        - ping
+      properties:
+        ping:
+          type: string
+          example: pong`;
+
+      const yamlDock = parse(content);
+      // eslint-disable-next-line @typescript-eslint/no-var-requires
+      const openapiV3Schema = await readFile(path.join(__dirname, './fixtures/sample-openapiv3.0.0-schema.json'), {
+        encoding: 'utf-8',
+      });
+
+      requestServiceMock = sandbox.fake.resolves(openapiV3Schema);
+      const service = new SchemaService.YAMLSchemaService(requestServiceMock);
+      service.registerCustomSchemaProvider(() => {
+        return new Promise<string | string[]>((resolve) => {
+          resolve('http://fakeschema.faketld');
+        });
+      });
+
+      const schema = await service.getSchemaForResource('', yamlDock.documents[0]);
+      expect(requestServiceMock).calledWithExactly('http://fakeschema.faketld');
+      expect(schema).to.not.be.null;
+    });
+
     it('should handle url with fragments when root object is schema', async () => {
       const content = `# yaml-language-server: $schema=https://json-schema.org/draft-07/schema#/definitions/schemaArray`;
       const yamlDock = parse(content);