test: harden handshake tests against timing and stale socket files

tests/unit_tests/test_launch_progress.py

@@ -23,6 +23,12 @@ class _Server:
         self.path = path
         self._srv = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
         self._srv.settimeout(2.0)
+        # A crashed previous run (with pid reuse) can leave the socket file behind,
+        # which would make bind() fail with "Address already in use".
+        try:
+            os.unlink(path)
+        except FileNotFoundError:
+            pass
         self._srv.bind(path)
         self._srv.listen(1)
         self._conn: socket.socket | None = None

tests/unit_tests/test_launch_window.py

@@ -142,7 +142,7 @@ def test_launch_window_notifies_launcher_ready(qtbot, bec_launch_window, monkeyp
     qtbot.addWidget(window)
     window.show()
     bec_launch_window._notify_launcher_ready(window)
-    qtbot.wait(10)
+    qtbot.waitUntil(lambda: calls == [("bec-gui-server", window)], timeout=1000)
 
     assert calls == [("bec-gui-server", window)]
 

tests/unit_tests/test_launcher_ready.py

@@ -26,6 +26,12 @@ def test_notify_launcher_ready_sends_ready(monkeypatch):
     path = _short_socket_path()
     srv = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
     srv.settimeout(2.0)
+    # A crashed previous run (with pid reuse) can leave the socket file behind,
+    # which would make bind() fail with "Address already in use".
+    try:
+        os.unlink(path)
+    except FileNotFoundError:
+        pass
     srv.bind(path)
     srv.listen(1)
     try:

tests/unit_tests/test_main_app.py

@@ -88,8 +88,7 @@ def test_main_app_notifies_launcher_ready_after_show(qtbot, mocked_client, monke
     qtbot.addWidget(app)
     app.show()
     qtbot.waitExposed(app)
-    qtbot.wait(10)
-
+    qtbot.waitUntil(lambda: calls == [("bec-app", app)], timeout=1000)
     assert calls == [("bec-app", app)]