fix(folder trust): add validation for trusted folder level (#12215)

Co-authored-by: Gal Zahavi <38544478+galz10@users.noreply.github.com>

packages/cli/src/config/trustedFolders.test.ts

@@ -424,3 +424,52 @@ describe('Trusted Folders Caching', () => {
     expect(readSpy).toHaveBeenCalledTimes(2);
   });
 });
+
+describe('invalid trust levels', () => {
+  const mockCwd = '/user/folder';
+  const mockRules: Record<string, TrustLevel> = {};
+
+  beforeEach(() => {
+    resetTrustedFoldersForTesting();
+    vi.spyOn(process, 'cwd').mockImplementation(() => mockCwd);
+    vi.spyOn(fs, 'readFileSync').mockImplementation((p) => {
+      if (p === getTrustedFoldersPath()) {
+        return JSON.stringify(mockRules);
+      }
+      return '{}';
+    });
+    vi.spyOn(fs, 'existsSync').mockImplementation(
+      (p) => p === getTrustedFoldersPath(),
+    );
+  });
+
+  afterEach(() => {
+    vi.restoreAllMocks();
+    // Clear the object
+    Object.keys(mockRules).forEach((key) => delete mockRules[key]);
+  });
+
+  it('should create a comprehensive error message for invalid trust level', () => {
+    mockRules[mockCwd] = 'INVALID_TRUST_LEVEL' as TrustLevel;
+
+    const { errors } = loadTrustedFolders();
+    const possibleValues = Object.values(TrustLevel).join(', ');
+    expect(errors.length).toBe(1);
+    expect(errors[0].message).toBe(
+      `Invalid trust level "INVALID_TRUST_LEVEL" for path "${mockCwd}". Possible values are: ${possibleValues}.`,
+    );
+  });
+
+  it('should throw a fatal error for invalid trust level', () => {
+    const mockSettings: Settings = {
+      security: {
+        folderTrust: {
+          enabled: true,
+        },
+      },
+    };
+    mockRules[mockCwd] = 'INVALID_TRUST_LEVEL' as TrustLevel;
+
+    expect(() => isWorkspaceTrusted(mockSettings)).toThrow(FatalConfigError);
+  });
+});