Add focus history and Alt-Tab window switching

scripts/tests/test_focus_history_isolated.py

@@ -0,0 +1,114 @@
+"""Focus history against real windows on a disposable nested compositor.
+
+FERESE_TEST_FOCUS_HISTORY=1 python3 scripts/tests/test_focus_history_isolated.py
+Requires built debug ferese/feresectl, foot, dbus-daemon, and a Wayland host.
+"""
+import json
+import os
+from pathlib import Path
+import signal
+import subprocess
+import tempfile
+import time
+import unittest
+
+
+@unittest.skipUnless(os.environ.get("FERESE_TEST_FOCUS_HISTORY") == "1", "nested focus test is opt-in")
+class FocusHistoryTest(unittest.TestCase):
+    def test_last_focus_crosses_workspaces_and_skips_closed_windows(self):
+        repo = Path(__file__).resolve().parents[2]
+        with tempfile.TemporaryDirectory(prefix="ferese-focus-test-") as temporary:
+            root = Path(temporary)
+            runtime = root / "runtime"
+            runtime.mkdir(mode=0o700)
+            config = root / "config/ferese"
+            config.mkdir(parents=True)
+            (config / "config.kdl").write_text("animations { enabled #false; }\n")
+            display = Path(os.environ["WAYLAND_DISPLAY"])
+            if not display.is_absolute():
+                display = Path(os.environ["XDG_RUNTIME_DIR"]) / display
+            env = dict(os.environ, WAYLAND_DISPLAY=str(display), XDG_RUNTIME_DIR=str(runtime),
+                       XDG_CONFIG_HOME=str(root / "config"), XDG_STATE_HOME=str(root / "state"))
+            env.pop("WAYLAND_SOCKET", None)
+            env.pop("FERESE_SHELL_CONTROL_SOCKET", None)
+            children = []
+
+            def launch(command, **kwargs):
+                child = subprocess.Popen(command, env=env, start_new_session=True, **kwargs)
+                children.append(child)
+                return child
+
+            def command(*args):
+                return json.loads(subprocess.check_output(
+                    [str(repo / "target/debug/feresectl"), *args], env=env, timeout=5
+                ))
+
+            def wait_for(predicate):
+                deadline = time.monotonic() + 10
+                while time.monotonic() < deadline:
+                    result = predicate()
+                    if result:
+                        return result
+                    time.sleep(.025)
+                self.fail("Timed out waiting for compositor state: " + (root / "compositor.log").read_text())
+
+            def focused():
+                result = command("get-focused-window")
+                return result["id"] if result else None
+
+            with (root / "compositor.log").open("w") as log:
+                try:
+                    bus = launch(["dbus-daemon", "--session", "--nofork", "--print-address=1"],
+                                 stdout=subprocess.PIPE, text=True)
+                    env["DBUS_SESSION_BUS_ADDRESS"] = bus.stdout.readline().strip()
+                    launch([str(repo / "target/debug/ferese"), "--backend", "nested"], stdout=log, stderr=log)
+                    wait_for(lambda: (runtime / "ferese/control.sock").is_socket())
+                    command("focus-last-window")
+                    self.assertIsNone(focused())
+                    env["WAYLAND_DISPLAY"] = str(next(
+                        path for path in runtime.glob("wayland-*") if not path.name.endswith(".lock")
+                    ))
+                    windows = []
+                    for index in range(3):
+                        app = f"ferese.test.focus.{index}"
+                        child = launch(["foot", "--app-id", app, "sleep", "120"], stdout=log, stderr=log)
+                        window = wait_for(lambda: next((w for w in command("get-windows")
+                                                       if w["app_id"] == app and w["width"] > 0), None))
+                        wait_for(lambda: focused() == window["id"])
+                        windows.append((child, window["id"]))
+                        if index == 1:
+                            command("workspace", "2")
+                    first, second, third = [window for _, window in windows]
+                    command("focus-last-window")
+                    self.assertEqual(focused(), second)
+                    self.assertEqual(next(w["name"] for w in command("get-workspaces") if w["active"]), "1")
+                    command("focus-last-window")
+                    self.assertEqual(focused(), third)
+                    self.assertEqual(next(w["name"] for w in command("get-workspaces") if w["active"]), "2")
+                    command("focus-mru-previous")
+                    self.assertEqual(focused(), first, "reverse traversal reaches least recent window")
+                    command("focus-mru-next")
+                    self.assertEqual(focused(), third)
+                    windows[1][0].terminate()
+                    windows[1][0].wait(timeout=3)
+                    wait_for(lambda: not any(w["id"] == second for w in command("get-windows")))
+                    command("focus-last-window")
+                    self.assertEqual(focused(), first, "closed windows must not consume a focus action")
+                    command("reload-config")
+                    command("focus-last-window")
+                    self.assertEqual(focused(), third, "reload must preserve focus history")
+                finally:
+                    for child in reversed(children):
+                        if child.poll() is None:
+                            os.killpg(child.pid, signal.SIGTERM)
+                            try:
+                                child.wait(timeout=3)
+                            except subprocess.TimeoutExpired:
+                                os.killpg(child.pid, signal.SIGKILL)
+                                child.wait(timeout=3)
+                        if child.stdout is not None:
+                            child.stdout.close()
+
+
+if __name__ == "__main__":
+    unittest.main()