fix(cursor): address second-round review feedback for auth module

- Add comprehensive unit tests for cursor-auth.test.ts
  - validateToken: valid/invalid tokens, short tokens, UUID formats, empty strings
  - extractUserInfo: JWT parsing, email handling, non-JWT tokens, malformed base64
  - saveCredentials/loadCredentials: round-trip, invalid JSON/types, missing fields
  - checkAuthStatus: authenticated/not authenticated, expired tokens, JWT exp, invalid dates
  - deleteCredentials: delete existing/non-existent files, multiple deletes
  - All tests use CCS_HOME env var for isolation, real file I/O, no mocks

- Fix dead try-catch around new Date() in checkAuthStatus()
  - Replace try-catch with isNaN check (new Date('garbage') returns Invalid Date, not throw)
  - Properly handle Invalid Date by checking isNaN(getTime())

- Fix email populated with sub claim in extractUserInfo()
  - Change email: decoded.email || decoded.sub to email: decoded.email || undefined
  - Prevent non-email values (UUIDs) from populating email field

- Add type guards for JSON.parse result in extractUserInfo()
  - Cast to Record<string, unknown> and validate types
  - Use typeof checks for email, userId, exp fields

src/cursor/cursor-auth.ts

@@ -164,11 +164,16 @@ export function extractUserInfo(
       }
       const decoded = JSON.parse(
         Buffer.from(payload.replace(/-/g, '+').replace(/_/g, '/'), 'base64').toString()
-      );
+      ) as Record<string, unknown>;
       return {
-        email: decoded.email || decoded.sub,
-        userId: decoded.sub || decoded.user_id,
-        exp: decoded.exp,
+        email: typeof decoded.email === 'string' ? decoded.email : undefined,
+        userId:
+          typeof decoded.sub === 'string'
+            ? decoded.sub
+            : typeof decoded.user_id === 'string'
+              ? decoded.user_id
+              : undefined,
+        exp: typeof decoded.exp === 'number' ? decoded.exp : undefined,
       };
     }
   } catch {
@@ -274,13 +279,11 @@ export function checkAuthStatus(): CursorAuthStatus {
   } else {
     // Fallback to importedAt heuristic
     const TOKEN_EXPIRY_HOURS = 24;
-    try {
-      const importedDate = new Date(credentials.importedAt);
+    const importedDate = new Date(credentials.importedAt);
+    if (!isNaN(importedDate.getTime())) {
       const now = new Date();
       tokenAge = Math.floor((now.getTime() - importedDate.getTime()) / (1000 * 60 * 60));
       expired = tokenAge >= TOKEN_EXPIRY_HOURS;
-    } catch {
-      // Invalid date format
     }
   }
 

tests/unit/cursor/cursor-auth.test.ts

@@ -0,0 +1,388 @@
+/**
+ * Unit tests for Cursor authentication module
+ */
+
+import { describe, it, expect, beforeEach, afterEach } from 'bun:test';
+import * as fs from 'fs';
+import * as path from 'path';
+import * as os from 'os';
+import type { CursorCredentials } from '../../../src/cursor/types';
+import {
+  validateToken,
+  extractUserInfo,
+  saveCredentials,
+  loadCredentials,
+  checkAuthStatus,
+  deleteCredentials,
+} from '../../../src/cursor/cursor-auth';
+
+// Test isolation
+let originalCcsHome: string | undefined;
+let tempDir: string;
+
+beforeEach(() => {
+  // Save original CCS_HOME
+  originalCcsHome = process.env.CCS_HOME;
+
+  // Create temp directory for test isolation
+  tempDir = fs.mkdtempSync(path.join(os.tmpdir(), 'ccs-cursor-test-'));
+  process.env.CCS_HOME = tempDir;
+});
+
+afterEach(() => {
+  // Restore original CCS_HOME
+  if (originalCcsHome !== undefined) {
+    process.env.CCS_HOME = originalCcsHome;
+  } else {
+    delete process.env.CCS_HOME;
+  }
+
+  // Clean up temp directory
+  if (fs.existsSync(tempDir)) {
+    fs.rmSync(tempDir, { recursive: true, force: true });
+  }
+});
+
+describe('validateToken', () => {
+  it('should accept valid token and machineId', () => {
+    const token = 'a'.repeat(50); // 50 chars minimum
+    const machineId = 'a'.repeat(32); // 32 hex chars
+    expect(validateToken(token, machineId)).toBe(true);
+  });
+
+  it('should reject 49-char token (too short)', () => {
+    const token = 'a'.repeat(49); // Just under minimum
+    const machineId = 'a'.repeat(32);
+    expect(validateToken(token, machineId)).toBe(false);
+  });
+
+  it('should reject 31-char hex UUID (too short)', () => {
+    const token = 'a'.repeat(50);
+    const machineId = 'a'.repeat(31); // Just under 32
+    expect(validateToken(token, machineId)).toBe(false);
+  });
+
+  it('should accept UUID with hyphens (strips them)', () => {
+    const token = 'a'.repeat(50);
+    const machineId = '12345678-1234-1234-1234-123456789abc'; // 36 chars with hyphens
+    expect(validateToken(token, machineId)).toBe(true);
+  });
+
+  it('should reject empty token', () => {
+    const machineId = 'a'.repeat(32);
+    expect(validateToken('', machineId)).toBe(false);
+  });
+
+  it('should reject empty machineId', () => {
+    const token = 'a'.repeat(50);
+    expect(validateToken(token, '')).toBe(false);
+  });
+
+  it('should reject non-hex characters in machineId', () => {
+    const token = 'a'.repeat(50);
+    const machineId = 'g'.repeat(32); // 'g' is not valid hex
+    expect(validateToken(token, machineId)).toBe(false);
+  });
+});
+
+describe('extractUserInfo', () => {
+  it('should extract email and sub from valid JWT', () => {
+    // JWT: {"email":"user@example.com","sub":"12345","exp":1234567890}
+    const payload = Buffer.from(
+      JSON.stringify({ email: 'user@example.com', sub: '12345', exp: 1234567890 })
+    ).toString('base64');
+    const token = `header.${payload}.signature`;
+
+    const result = extractUserInfo(token);
+    expect(result).toEqual({
+      email: 'user@example.com',
+      userId: '12345',
+      exp: 1234567890,
+    });
+  });
+
+  it('should return undefined email when only sub claim exists', () => {
+    // JWT: {"sub":"uuid-12345","exp":1234567890}
+    const payload = Buffer.from(
+      JSON.stringify({ sub: 'uuid-12345', exp: 1234567890 })
+    ).toString('base64');
+    const token = `header.${payload}.signature`;
+
+    const result = extractUserInfo(token);
+    expect(result).toEqual({
+      email: undefined,
+      userId: 'uuid-12345',
+      exp: 1234567890,
+    });
+  });
+
+  it('should return null for non-JWT token', () => {
+    const token = 'a'.repeat(50); // Plain token
+    const result = extractUserInfo(token);
+    expect(result).toBe(null);
+  });
+
+  it('should return null for malformed base64', () => {
+    const token = 'header.!!!invalid-base64!!!.signature';
+    const result = extractUserInfo(token);
+    expect(result).toBe(null);
+  });
+
+  it('should handle JWT with user_id instead of sub', () => {
+    // JWT: {"email":"user@example.com","user_id":"67890"}
+    const payload = Buffer.from(
+      JSON.stringify({ email: 'user@example.com', user_id: '67890' })
+    ).toString('base64');
+    const token = `header.${payload}.signature`;
+
+    const result = extractUserInfo(token);
+    expect(result).toEqual({
+      email: 'user@example.com',
+      userId: '67890',
+      exp: undefined,
+    });
+  });
+});
+
+describe('saveCredentials and loadCredentials', () => {
+  it('should save and load credentials successfully', () => {
+    const credentials: CursorCredentials = {
+      accessToken: 'a'.repeat(50),
+      machineId: 'b'.repeat(32),
+      authMethod: 'auto-detect',
+      importedAt: new Date().toISOString(),
+    };
+
+    saveCredentials(credentials);
+    const loaded = loadCredentials();
+
+    expect(loaded).toEqual(credentials);
+  });
+
+  it('should return null when no credentials file exists', () => {
+    const loaded = loadCredentials();
+    expect(loaded).toBe(null);
+  });
+
+  it('should create directory with restrictive permissions', () => {
+    const credentials: CursorCredentials = {
+      accessToken: 'a'.repeat(50),
+      machineId: 'b'.repeat(32),
+      authMethod: 'manual',
+      importedAt: new Date().toISOString(),
+    };
+
+    saveCredentials(credentials);
+
+    // CCS_HOME is set to tempDir, but getCcsDir() appends '.ccs' to it
+    const credDir = path.join(tempDir, '.ccs', 'cursor');
+    expect(fs.existsSync(credDir)).toBe(true);
+
+    // Check directory permissions (skip on Windows)
+    if (process.platform !== 'win32') {
+      const stats = fs.statSync(credDir);
+      const mode = stats.mode & 0o777;
+      expect(mode).toBe(0o700);
+    }
+  });
+
+  it('should return null for invalid JSON in credentials file', () => {
+    const credPath = path.join(tempDir, 'cursor', 'credentials.json');
+    fs.mkdirSync(path.dirname(credPath), { recursive: true });
+    fs.writeFileSync(credPath, 'invalid json{{{');
+
+    const loaded = loadCredentials();
+    expect(loaded).toBe(null);
+  });
+
+  it('should return null for credentials missing required fields', () => {
+    const credPath = path.join(tempDir, 'cursor', 'credentials.json');
+    fs.mkdirSync(path.dirname(credPath), { recursive: true });
+    fs.writeFileSync(
+      credPath,
+      JSON.stringify({
+        accessToken: 'token',
+        // Missing machineId, authMethod, importedAt
+      })
+    );
+
+    const loaded = loadCredentials();
+    expect(loaded).toBe(null);
+  });
+
+  it('should return null for credentials with wrong types', () => {
+    const credPath = path.join(tempDir, 'cursor', 'credentials.json');
+    fs.mkdirSync(path.dirname(credPath), { recursive: true });
+    fs.writeFileSync(
+      credPath,
+      JSON.stringify({
+        accessToken: 123, // Wrong type (number instead of string)
+        machineId: 'abc',
+        authMethod: 'auto-detect',
+        importedAt: new Date().toISOString(),
+      })
+    );
+
+    const loaded = loadCredentials();
+    expect(loaded).toBe(null);
+  });
+
+  it('should return null for invalid authMethod', () => {
+    const credPath = path.join(tempDir, 'cursor', 'credentials.json');
+    fs.mkdirSync(path.dirname(credPath), { recursive: true });
+    fs.writeFileSync(
+      credPath,
+      JSON.stringify({
+        accessToken: 'token',
+        machineId: 'abc',
+        authMethod: 'invalid-method', // Invalid authMethod
+        importedAt: new Date().toISOString(),
+      })
+    );
+
+    const loaded = loadCredentials();
+    expect(loaded).toBe(null);
+  });
+});
+
+describe('checkAuthStatus', () => {
+  it('should return not authenticated when no credentials exist', () => {
+    const status = checkAuthStatus();
+    expect(status.authenticated).toBe(false);
+    expect(status.credentials).toBeUndefined();
+  });
+
+  it('should return authenticated for valid credentials', () => {
+    const credentials: CursorCredentials = {
+      accessToken: 'a'.repeat(50),
+      machineId: 'b'.repeat(32),
+      authMethod: 'auto-detect',
+      importedAt: new Date().toISOString(),
+    };
+
+    saveCredentials(credentials);
+    const status = checkAuthStatus();
+
+    expect(status.authenticated).toBe(true);
+    expect(status.credentials).toEqual(credentials);
+    expect(status.expired).toBe(false);
+    expect(status.tokenAge).toBeDefined();
+    expect(status.tokenAge).toBeLessThan(1); // Just imported
+  });
+
+  it('should detect expired credentials (importedAt > 24h ago)', () => {
+    // Create credentials from 25 hours ago
+    const past = new Date();
+    past.setHours(past.getHours() - 25);
+
+    const credentials: CursorCredentials = {
+      accessToken: 'a'.repeat(50),
+      machineId: 'b'.repeat(32),
+      authMethod: 'manual',
+      importedAt: past.toISOString(),
+    };
+
+    saveCredentials(credentials);
+    const status = checkAuthStatus();
+
+    expect(status.authenticated).toBe(true);
+    expect(status.expired).toBe(true);
+    expect(status.tokenAge).toBeGreaterThanOrEqual(24);
+  });
+
+  it('should return not authenticated for invalid token format', () => {
+    const credentials: CursorCredentials = {
+      accessToken: 'short', // Invalid (too short)
+      machineId: 'b'.repeat(32),
+      authMethod: 'manual',
+      importedAt: new Date().toISOString(),
+    };
+
+    saveCredentials(credentials);
+    const status = checkAuthStatus();
+
+    expect(status.authenticated).toBe(false);
+  });
+
+  it('should use JWT exp claim when available', () => {
+    // Create JWT token that expired 1 hour ago
+    const expiredTime = Math.floor(Date.now() / 1000) - 3600;
+    const payload = Buffer.from(
+      JSON.stringify({ email: 'test@example.com', sub: '123', exp: expiredTime })
+    ).toString('base64');
+    const jwtToken = `header.${payload}.signature`;
+
+    const credentials: CursorCredentials = {
+      accessToken: jwtToken,
+      machineId: 'b'.repeat(32),
+      authMethod: 'auto-detect',
+      importedAt: new Date().toISOString(), // Recent import
+    };
+
+    saveCredentials(credentials);
+    const status = checkAuthStatus();
+
+    expect(status.authenticated).toBe(true);
+    expect(status.expired).toBe(true); // Should detect expiry from JWT exp
+  });
+
+  it('should handle invalid importedAt date gracefully', () => {
+    // Create credentials with valid format but garbage date value
+    const credentials: CursorCredentials = {
+      accessToken: 'a'.repeat(50),
+      machineId: 'b'.repeat(32),
+      authMethod: 'manual',
+      importedAt: 'invalid-date-garbage-2026-99-99T99:99:99Z',
+    };
+
+    saveCredentials(credentials);
+    const status = checkAuthStatus();
+
+    // Should still authenticate if token format is valid
+    expect(status.authenticated).toBe(true);
+    // tokenAge should be undefined due to invalid date (NaN from getTime())
+    expect(status.tokenAge).toBeUndefined();
+    // expired should be false (defaults to false when date parsing fails)
+    expect(status.expired).toBe(false);
+  });
+});
+
+describe('deleteCredentials', () => {
+  it('should delete existing credentials file and return true', () => {
+    const credentials: CursorCredentials = {
+      accessToken: 'a'.repeat(50),
+      machineId: 'b'.repeat(32),
+      authMethod: 'auto-detect',
+      importedAt: new Date().toISOString(),
+    };
+
+    saveCredentials(credentials);
+    expect(loadCredentials()).not.toBe(null);
+
+    const result = deleteCredentials();
+    expect(result).toBe(true);
+    expect(loadCredentials()).toBe(null);
+  });
+
+  it('should return false when credentials file does not exist', () => {
+    const result = deleteCredentials();
+    expect(result).toBe(false);
+  });
+
+  it('should handle multiple delete calls gracefully', () => {
+    const credentials: CursorCredentials = {
+      accessToken: 'a'.repeat(50),
+      machineId: 'b'.repeat(32),
+      authMethod: 'manual',
+      importedAt: new Date().toISOString(),
+    };
+
+    saveCredentials(credentials);
+
+    // First delete should succeed
+    expect(deleteCredentials()).toBe(true);
+
+    // Second delete should return false (already deleted)
+    expect(deleteCredentials()).toBe(false);
+  });
+});