message: improvement: server only LSP bugfix for config extensions
diff: @@ -194,9 +194,11 @@ export class GraphQLLanguageService {
  // Check if there are custom validation rules to be used
  let customRules: ValidationRule[] | null = null;
  - const customValidationRules = extensions.customValidationRules;
  - if (customValidationRules) {
  - customRules = customValidationRules(this._graphQLConfig);
  + if (
  + extensions?.customValidationRules &&
  + typeof extensions.customValidationRules === 'function'
  + ) {
  + customRules = extensions.customValidationRules(this._graphQLConfig);
  /* eslint-enable no-implicit-coercion */
  }
  