fix: harden restart_claude_desktop across platforms (#33)

- Linux (and any non-desktop platform): refuse instead of 'pkill claude',
  which substring-matched running Claude Code CLI sessions and relaunched
  the CLI, not a desktop app. New restart_supported() gates the button.
- macOS: wait (<=5s) for the old instance to exit before 'open -a Claude'
  so the relaunch can't re-activate the dying process. Runs off the UI
  thread via a RestartWorker.
- Windows: verify the Start-menu shortcut exists BEFORE taskkill, so an
  MSIX/Store install is never killed without a relaunch path.

Closes #33

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

tests/test_core.py

@@ -934,11 +934,13 @@ class _FakeCompletedProcess:
 
 
 def test_restart_claude_desktop_macos_commands(monkeypatch):
-    """macOS: pkill -x "Claude" then open -a Claude, in that order."""
+    """macOS: pkill -x "Claude", wait for exit (pgrep), then open -a Claude."""
     calls = []
 
     def fake_run(cmd, **kwargs):
         calls.append(cmd)
+        if cmd[0] == "pgrep":
+            return _FakeCompletedProcess(returncode=1)  # already exited
         return _FakeCompletedProcess(returncode=0)
 
     monkeypatch.setattr(c.sys, "platform", "darwin")
@@ -946,14 +948,14 @@ def test_restart_claude_desktop_macos_commands(monkeypatch):
     result = c.restart_claude_desktop()
     assert result.success
     assert calls[0] == ["pkill", "-x", "Claude"]
-    assert calls[1] == ["open", "-a", "Claude"]
+    assert calls[-1] == ["open", "-a", "Claude"]
 
 
 def test_restart_claude_desktop_macos_pkill_not_running_is_fine(monkeypatch):
     """pkill exiting non-zero (nothing to kill) must NOT be treated as failure."""
 
     def fake_run(cmd, **kwargs):
-        if cmd[0] == "pkill":
+        if cmd[0] in ("pkill", "pgrep"):
             return _FakeCompletedProcess(returncode=1)  # no matching process
         return _FakeCompletedProcess(returncode=0)
 
@@ -977,12 +979,12 @@ def test_restart_claude_desktop_macos_relaunch_failure_reported(monkeypatch):
 
 
 def test_restart_claude_desktop_macos_pkill_binary_missing_does_not_raise(monkeypatch):
-    """pkill raising OSError (binary missing) must be swallowed, not propagated --
-    relaunch is still attempted."""
+    """pkill/pgrep raising OSError (binary missing) must be swallowed, not
+    propagated -- relaunch is still attempted."""
 
     def fake_run(cmd, **kwargs):
-        if cmd[0] == "pkill":
-            raise OSError("pkill not found")
+        if cmd[0] in ("pkill", "pgrep"):
+            raise OSError("binary not found")
         return _FakeCompletedProcess(returncode=0)
 
     monkeypatch.setattr(c.sys, "platform", "darwin")
@@ -991,7 +993,45 @@ def test_restart_claude_desktop_macos_pkill_binary_missing_does_not_raise(monkey
     assert result.success
 
 
-def test_restart_claude_desktop_windows_commands(monkeypatch):
+def test_restart_claude_desktop_macos_gives_up_if_app_wont_quit(monkeypatch):
+    monkeypatch.setattr(c.sys, "platform", "darwin")
+    monkeypatch.setattr(c, "_run_quiet", lambda cmd: None)
+    monkeypatch.setattr(c, "_macos_claude_running", lambda: True)  # never exits
+    monkeypatch.setattr(c, "_MACOS_QUIT_WAIT_S", 0.2)
+    res = c.restart_claude_desktop()
+    assert res.success is False
+    assert "quit" in res.detail.lower()
+
+
+def test_restart_claude_desktop_macos_waits_for_exit_then_relaunches(monkeypatch):
+    monkeypatch.setattr(c.sys, "platform", "darwin")
+    monkeypatch.setattr(c, "_run_quiet", lambda cmd: None)
+    alive = iter([True, True, False])  # exits on the third poll
+    monkeypatch.setattr(c, "_macos_claude_running", lambda: next(alive))
+
+    launched = []
+
+    def fake_run(cmd, **kwargs):
+        launched.append(cmd)
+        return _FakeCompletedProcess(returncode=0)
+
+    monkeypatch.setattr(c.subprocess, "run", fake_run)
+    res = c.restart_claude_desktop()
+    assert res.success is True
+    assert launched == [["open", "-a", "Claude"]]
+
+
+@pytest.fixture
+def windows_shortcut(tmp_path, monkeypatch):
+    """A fake %APPDATA% containing the Claude Start-menu shortcut."""
+    monkeypatch.setenv("APPDATA", str(tmp_path))
+    lnk = tmp_path / "Microsoft" / "Windows" / "Start Menu" / "Programs" / "Claude.lnk"
+    lnk.parent.mkdir(parents=True)
+    lnk.write_bytes(b"")
+    return lnk
+
+
+def test_restart_claude_desktop_windows_commands(monkeypatch, windows_shortcut):
     """Windows: taskkill the process, then relaunch via the Start-menu shortcut."""
     calls = []
 
@@ -1008,7 +1048,7 @@ def test_restart_claude_desktop_windows_commands(monkeypatch):
     assert calls[1][-1].endswith("Claude.lnk")
 
 
-def test_restart_claude_desktop_windows_relaunch_failure_reported(monkeypatch):
+def test_restart_claude_desktop_windows_relaunch_failure_reported(monkeypatch, windows_shortcut):
     def fake_run(cmd, **kwargs):
         if cmd[0] == "cmd":
             return _FakeCompletedProcess(returncode=1, stderr="not found")
@@ -1021,43 +1061,37 @@ def test_restart_claude_desktop_windows_relaunch_failure_reported(monkeypatch):
     assert "not found" in result.detail
 
 
-def test_restart_claude_desktop_linux_commands(monkeypatch):
-    """Linux: pkill claude, then relaunch via a detached Popen (no waiting)."""
-    run_calls = []
-    popen_calls = []
+def test_restart_claude_desktop_windows_missing_shortcut_refuses_before_killing(
+    monkeypatch, tmp_path
+):
+    killed = []
+    monkeypatch.setattr(c, "_run_quiet", lambda cmd: killed.append(cmd))
+    monkeypatch.setattr(c.sys, "platform", "win32")
+    monkeypatch.setenv("APPDATA", str(tmp_path))  # no Claude.lnk under here (MSIX case)
+    res = c.restart_claude_desktop()
+    assert res.success is False
+    assert "shortcut" in res.detail.lower()
+    assert killed == []  # Claude must NOT be killed when it can't be relaunched
 
-    def fake_run(cmd, **kwargs):
-        run_calls.append(cmd)
-        return _FakeCompletedProcess(returncode=0)
-
-    class _FakePopen:
-        def __init__(self, cmd, **kwargs):
-            popen_calls.append((cmd, kwargs))
 
+def test_restart_supported_only_on_desktop_platforms(monkeypatch):
+    monkeypatch.setattr(c.sys, "platform", "darwin")
+    assert c.restart_supported()
+    monkeypatch.setattr(c.sys, "platform", "win32")
+    assert c.restart_supported()
     monkeypatch.setattr(c.sys, "platform", "linux")
-    monkeypatch.setattr(c.subprocess, "run", fake_run)
-    monkeypatch.setattr(c.subprocess, "Popen", _FakePopen)
-    result = c.restart_claude_desktop()
-    assert result.success
-    assert run_calls == [["pkill", "claude"]]
-    cmd, kwargs = popen_calls[0]
-    assert cmd == ["claude"]
-    assert kwargs.get("start_new_session") is True
+    assert not c.restart_supported()
 
 
-def test_restart_claude_desktop_linux_popen_failure_reported(monkeypatch):
-    def fake_run(cmd, **kwargs):
-        return _FakeCompletedProcess(returncode=0)
-
-    def fake_popen(cmd, **kwargs):
-        raise OSError("no such file or directory")
-
+def test_restart_claude_desktop_linux_refuses_without_touching_processes(monkeypatch):
+    """There is no Claude Desktop on Linux; 'pkill claude' would substring-match
+    running Claude Code CLI sessions. The restart must refuse outright."""
+    killed = []
+    monkeypatch.setattr(c, "_run_quiet", lambda cmd: killed.append(cmd))
     monkeypatch.setattr(c.sys, "platform", "linux")
-    monkeypatch.setattr(c.subprocess, "run", fake_run)
-    monkeypatch.setattr(c.subprocess, "Popen", fake_popen)
-    result = c.restart_claude_desktop()
-    assert not result.success
-    assert "Claude Desktop" in result.detail
+    res = c.restart_claude_desktop()
+    assert res.success is False
+    assert killed == []  # nothing killed, nothing spawned
 
 
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