feat: add support for draft-04 (2019 and 2020 included) json schemas while supporting draft-07

package.json

@@ -31,6 +31,7 @@
   },
   "dependencies": {
     "ajv": "^8.11.0",
+    "ajv-draft-04": "^1.0.0",
     "lodash": "4.17.21",
     "prettier": "^3.0.0",
     "request-light": "^0.5.7",

src/languageservice/services/yamlSchemaService.ts

@@ -28,16 +28,22 @@
 import { SchemaVersions } from '../yamlTypes';
 
 import Ajv, { DefinedError } from 'ajv';
+import Ajv2019 from 'ajv/dist/2019';
+import Ajv2020 from 'ajv/dist/2020';
+import Ajv04 from 'ajv-draft-04';
 import { getSchemaTitle } from '../utils/schemaUtils';
 
-const localize = nls.loadMessageBundle();
-
 const ajv = new Ajv();
 
-// 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);
+const draft6MetaSchema = require('ajv/dist/refs/json-schema-draft-06.json');
+ajv.addMetaSchema(draft6MetaSchema);
+
+const ajv04 = new Ajv04();
+const ajv2019 = new Ajv2019();
+const ajv2020 = new Ajv2020();
+
+const localize = nls.loadMessageBundle();
 
 export declare type CustomSchemaProvider = (uri: string) => Promise<string | string[]>;
 
@@ -164,9 +170,36 @@
     let schema: JSONSchema = schemaToResolve.schema;
     const contextService = this.contextService;
 
-    if (!schema07Validator(schema)) {
+    let validationErrors: DefinedError[] = [];
+    switch (this.normalizeId(schema.$schema)) {
+      case ajv04.defaultMeta(): {
+        if (!ajv04.validateSchema(schema)) {
+          validationErrors = validationErrors.concat(ajv04.errors as DefinedError[]);
+        }
+        break;
+      }
+      case ajv2019.defaultMeta(): {
+        if (!ajv2019.validateSchema(schema)) {
+          validationErrors = validationErrors.concat(ajv2019.errors as DefinedError[]);
+        }
+        break;
+      }
+      case ajv2020.defaultMeta(): {
+        if (!ajv2020.validateSchema(schema)) {
+          validationErrors = validationErrors.concat(ajv2020.errors as DefinedError[]);
+        }
+        break;
+      }
+      default:
+        if (!ajv.validateSchema(schema)) {
+          validationErrors = validationErrors.concat(ajv.errors as DefinedError[]);
+        }
+        break;
+    }
+
+    if (validationErrors.length > 0) {
       const errs: string[] = [];
-      for (const err of schema07Validator.errors as DefinedError[]) {
+      for (const err of validationErrors) {
         errs.push(`${err.instancePath} : ${err.message}`);
       }
       resolveErrors.push(`Schema '${getSchemaTitle(schemaToResolve.schema, schemaURL)}' is not valid:\n${errs.join('\n')}`);