feat: consolidate remote MCP servers to use url in config (#13762)

packages/core/src/utils/errors.test.ts

@@ -0,0 +1,42 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { describe, it, expect } from 'vitest';
+import { isAuthenticationError, UnauthorizedError } from './errors.js';
+
+describe('isAuthenticationError', () => {
+  it('should detect error with code: 401 property (MCP SDK style)', () => {
+    const error = { code: 401, message: 'Unauthorized' };
+    expect(isAuthenticationError(error)).toBe(true);
+  });
+
+  it('should detect UnauthorizedError instance', () => {
+    const error = new UnauthorizedError('Authentication required');
+    expect(isAuthenticationError(error)).toBe(true);
+  });
+
+  it('should return false for 404 errors', () => {
+    const error = { code: 404, message: 'Not Found' };
+    expect(isAuthenticationError(error)).toBe(false);
+  });
+
+  it('should handle null and undefined gracefully', () => {
+    expect(isAuthenticationError(null)).toBe(false);
+    expect(isAuthenticationError(undefined)).toBe(false);
+  });
+
+  it('should handle non-error objects', () => {
+    expect(isAuthenticationError('string error')).toBe(false);
+    expect(isAuthenticationError(123)).toBe(false);
+    expect(isAuthenticationError({})).toBe(false);
+  });
+
+  it('should detect 401 in various message formats', () => {
+    expect(isAuthenticationError(new Error('401 Unauthorized'))).toBe(true);
+    expect(isAuthenticationError(new Error('HTTP 401'))).toBe(true);
+    expect(isAuthenticationError(new Error('Status code: 401'))).toBe(true);
+  });
+});