test(worktree-isolation): add worktree detection tests

v2/src/lib/agent-dispatcher.test.ts

@@ -205,6 +205,7 @@ import {
   isSidecarAlive,
   setSidecarAlive,
   waitForPendingPersistence,
+  detectWorktreeFromCwd,
 } from './agent-dispatcher';
 
 // Stop any previous dispatcher between tests so `unlistenMsg` is null and start works
@@ -622,4 +623,71 @@ describe('agent-dispatcher', () => {
       await expect(waitForPendingPersistence()).resolves.toBeUndefined();
     });
   });
+
+  describe('detectWorktreeFromCwd', () => {
+    it('detects Claude Code worktree path', () => {
+      const result = detectWorktreeFromCwd('/home/user/project/.claude/worktrees/my-session');
+      expect(result).toBe('/.claude/worktrees/my-session');
+    });
+
+    it('detects Codex worktree path', () => {
+      const result = detectWorktreeFromCwd('/home/user/project/.codex/worktrees/task-1');
+      expect(result).toBe('/.codex/worktrees/task-1');
+    });
+
+    it('detects Cursor worktree path', () => {
+      const result = detectWorktreeFromCwd('/home/user/project/.cursor/worktrees/feature-x');
+      expect(result).toBe('/.cursor/worktrees/feature-x');
+    });
+
+    it('returns null for non-worktree CWD', () => {
+      expect(detectWorktreeFromCwd('/home/user/project')).toBeNull();
+      expect(detectWorktreeFromCwd('/tmp/work')).toBeNull();
+    });
+
+    it('returns null for empty string', () => {
+      expect(detectWorktreeFromCwd('')).toBeNull();
+    });
+  });
+
+  describe('init event CWD worktree detection', () => {
+    beforeEach(async () => {
+      await startAgentDispatcher();
+    });
+
+    it('calls setSessionWorktree when init CWD contains worktree path', async () => {
+      const { setSessionWorktree } = await import('./stores/conflicts.svelte');
+
+      // Override the mock adapter to return init with worktree CWD
+      const { adaptMessage } = await import('./adapters/message-adapters');
+      (adaptMessage as ReturnType<typeof vi.fn>).mockReturnValueOnce([{
+        id: 'msg-wt',
+        type: 'init',
+        content: { sessionId: 'sdk-wt', model: 'claude-sonnet-4-20250514', cwd: '/home/user/repo/.claude/worktrees/my-session', tools: [] },
+        timestamp: Date.now(),
+      }]);
+
+      capturedCallbacks.msg!({
+        type: 'agent_event',
+        sessionId: 'sess-wt',
+        event: { type: 'system', subtype: 'init' },
+      });
+
+      expect(setSessionWorktree).toHaveBeenCalledWith('sess-wt', '/.claude/worktrees/my-session');
+    });
+
+    it('does not call setSessionWorktree for non-worktree CWD', async () => {
+      const { setSessionWorktree } = await import('./stores/conflicts.svelte');
+      (setSessionWorktree as ReturnType<typeof vi.fn>).mockClear();
+
+      capturedCallbacks.msg!({
+        type: 'agent_event',
+        sessionId: 'sess-normal',
+        event: { type: 'system', subtype: 'init' },
+      });
+
+      // The default mock returns cwd: '/tmp' which is not a worktree
+      expect(setSessionWorktree).not.toHaveBeenCalled();
+    });
+  });
 });