Fix tmux attach disconnect cleanup for issue #2197

src/cli/__tests__/launch.test.ts

@@ -258,12 +258,9 @@ describe('runClaude OMC HUD behavior', () => {
 
     runClaude('/tmp/cwd', [], 'test-session');
 
-    const calls = vi.mocked(execFileSync).mock.calls;
-    const tmuxCall = calls.find(([cmd]) => cmd === 'tmux');
-    expect(tmuxCall).toBeDefined();
-
-    const tmuxArgs = tmuxCall![1] as string[];
-    expect(tmuxArgs).not.toContain('split-window');
+    const tmuxCalls = vi.mocked(execFileSync).mock.calls.filter(([cmd]) => cmd === 'tmux');
+    expect(tmuxCalls.length).toBeGreaterThan(0);
+    expect(tmuxCalls.every(([, tmuxArgs]) => !(tmuxArgs as string[]).includes('split-window'))).toBe(true);
   });
 });
 
@@ -287,8 +284,8 @@ describe('runClaude outside-tmux — mouse scrolling (issue #890)', () => {
   it('uses session-targeted mouse option instead of global (-t sessionName, not -g)', () => {
     runClaude('/tmp', [], 'sid');
 
-    const calls = vi.mocked(execFileSync).mock.calls;
-    const tmuxCall = calls.find(([cmd]) => cmd === 'tmux');
+    const tmuxCalls = vi.mocked(execFileSync).mock.calls.filter(([cmd]) => cmd === 'tmux');
+    const tmuxCall = tmuxCalls.find(([, args]) => (args as string[])[0] === 'set-option');
     expect(tmuxCall).toBeDefined();
 
     const tmuxArgs = tmuxCall![1] as string[];
@@ -306,8 +303,9 @@ describe('runClaude outside-tmux — mouse scrolling (issue #890)', () => {
   it('does not set terminal-overrides in tmux args', () => {
     runClaude('/tmp', [], 'sid');
 
-    const calls = vi.mocked(execFileSync).mock.calls;
-    const tmuxCall = calls.find(([cmd]) => cmd === 'tmux');
+    const tmuxCalls = vi.mocked(execFileSync).mock.calls.filter(([cmd]) => cmd === 'tmux');
+    const tmuxCall = tmuxCalls.find(([, args]) => (args as string[])[0] === 'new-session');
+    expect(tmuxCall).toBeDefined();
     const tmuxArgs = tmuxCall![1] as string[];
 
     expect(tmuxArgs).not.toContain('terminal-overrides');
@@ -317,16 +315,57 @@ describe('runClaude outside-tmux — mouse scrolling (issue #890)', () => {
   it('places mouse mode setup before attach-session', () => {
     runClaude('/tmp', [], 'sid');
 
-    const calls = vi.mocked(execFileSync).mock.calls;
-    const tmuxCall = calls.find(([cmd]) => cmd === 'tmux');
-    const tmuxArgs = tmuxCall![1] as string[];
+    const tmuxCalls = vi.mocked(execFileSync).mock.calls
+      .map(([cmd, tmuxArgs]) => ({ cmd, tmuxArgs: tmuxArgs as string[] }))
+      .filter(({ cmd }) => cmd === 'tmux');
 
-    const mouseIdx = tmuxArgs.indexOf('mouse');
-    const attachIdx = tmuxArgs.indexOf('attach-session');
+    const mouseIdx = tmuxCalls.findIndex(({ tmuxArgs }) => tmuxArgs[0] === 'set-option');
+    const attachIdx = tmuxCalls.findIndex(({ tmuxArgs }) => tmuxArgs[0] === 'attach-session');
     expect(mouseIdx).toBeGreaterThanOrEqual(0);
     expect(attachIdx).toBeGreaterThanOrEqual(0);
     expect(mouseIdx).toBeLessThan(attachIdx);
   });
+
+  it('preserves a valid detached session when attach-session is interrupted', () => {
+    (execFileSync as ReturnType<typeof vi.fn>).mockImplementation((cmd: string, args: string[]) => {
+      if (cmd !== 'tmux') return Buffer.from('');
+      if (args[0] === 'attach-session') {
+        throw new Error('attach interrupted');
+      }
+      return Buffer.from('');
+    });
+
+    runClaude('/tmp', [], 'sid');
+
+    const tmuxCalls = vi.mocked(execFileSync).mock.calls
+      .filter(([cmd]) => cmd === 'tmux')
+      .map(([, tmuxArgs]) => tmuxArgs as string[]);
+
+    expect(tmuxCalls.map((tmuxArgs) => tmuxArgs[0])).toEqual([
+      'new-session',
+      'set-option',
+      'attach-session',
+      'has-session',
+    ]);
+    expect(tmuxCalls.some((tmuxArgs) => tmuxArgs[0] === 'kill-session')).toBe(false);
+    expect(vi.mocked(execFileSync).mock.calls.find(([cmd]) => cmd === 'claude')).toBeUndefined();
+    expect(processExitSpy).not.toHaveBeenCalled();
+  });
+
+  it('falls back to direct launch when detached session creation fails', () => {
+    (execFileSync as ReturnType<typeof vi.fn>).mockImplementation((cmd: string, args: string[]) => {
+      if (cmd === 'tmux' && args[0] === 'new-session') {
+        throw new Error('tmux launch failed');
+      }
+      return Buffer.from('');
+    });
+
+    runClaude('/tmp', ['--dangerously-skip-permissions'], 'sid');
+
+    const calls = vi.mocked(execFileSync).mock.calls;
+    expect(calls.filter(([cmd]) => cmd === 'tmux')).toHaveLength(1);
+    expect(calls.find(([cmd, args]) => cmd === 'claude' && (args as string[])[0] === '--dangerously-skip-permissions')).toBeDefined();
+  });
 });
 
 // ---------------------------------------------------------------------------

src/cli/launch.ts

@@ -409,25 +409,31 @@ function runClaudeOutsideTmux(cwd: string, args: string[], _sessionId: string):
   const claudeCmd = wrapWithLoginShell(`sleep 0.3; perl -e 'use POSIX;tcflush(0,TCIFLUSH)' 2>/dev/null; ${rawClaudeCmd}`);
   const sessionName = buildTmuxSessionName(cwd);
 
-  const tmuxArgs = [
-    'new-session', '-d', '-s', sessionName, '-c', cwd,
-    claudeCmd,
-    ';', 'set-option', '-t', sessionName, 'mouse', 'on',
-  ];
+  try {
+    execFileSync('tmux', ['new-session', '-d', '-s', sessionName, '-c', cwd, claudeCmd], { stdio: 'inherit' });
+  } catch {
+    runClaudeDirect(cwd, args);
+    return;
+  }
 
-  // Attach to session
-  tmuxArgs.push(';', 'attach-session', '-t', sessionName);
+  try {
+    execFileSync('tmux', ['set-option', '-t', sessionName, 'mouse', 'on'], { stdio: 'ignore' });
+  } catch {
+    /* non-fatal — user's tmux may not support these options */
+  }
 
   try {
-    execFileSync('tmux', tmuxArgs, { stdio: 'inherit' });
+    execFileSync('tmux', ['attach-session', '-t', sessionName], { stdio: 'inherit' });
   } catch {
-    // tmux attach failed — kill the orphaned detached session that
-    // new-session -d just created so they don't accumulate.
+    // If the detached session still exists, preserve it so interrupted
+    // attach paths (SSH disconnect, terminal drop, etc.) do not kill or
+    // duplicate a valid Claude session.
     try {
-      execFileSync('tmux', ['kill-session', '-t', sessionName], { stdio: 'ignore' });
-    } catch { /* session may already be gone */ }
-    // fall back to direct launch
-    runClaudeDirect(cwd, args);
+      execFileSync('tmux', ['has-session', '-t', sessionName], { stdio: 'ignore' });
+      return;
+    } catch {
+      runClaudeDirect(cwd, args);
+    }
   }
 }