feat: ManagedService spawns detached driver services that outlive python

tests/unit/test_hosts.py

@@ -1,10 +1,22 @@
 import http.server
 import json
+import os
+import stat
+import sys
 import threading
+import time
 
 import pytest
 
-from wabot.hosts import ExternalServer, build_options, normalize_browser, service_alive
+from wabot.hosts import (
+    ExternalServer,
+    ManagedService,
+    build_options,
+    find_driver_binary,
+    normalize_browser,
+    service_alive,
+    stop_service,
+)
 
 
 class TestNormalizeBrowser:
@@ -119,3 +131,74 @@ class TestServiceAliveNonHttpResponder:
                 ExternalServer(f"http://127.0.0.1:{port}").ensure_running()
         finally:
             server.close()
+
+
+STUB_DRIVER = """\
+#!{python}
+import http.server, json, sys
+port = int(sys.argv[1].split("=", 1)[1])
+class H(http.server.BaseHTTPRequestHandler):
+    def do_GET(self):
+        body = json.dumps({{"value": {{"ready": True, "message": ""}}}}).encode()
+        self.send_response(200); self.end_headers(); self.wfile.write(body)
+    def log_message(self, *a): pass
+http.server.HTTPServer(("127.0.0.1", port), H).serve_forever()
+"""
+
+
+@pytest.fixture
+def stub_driver(tmp_path):
+    path = tmp_path / "chromedriver"
+    path.write_text(STUB_DRIVER.format(python=sys.executable))
+    path.chmod(path.stat().st_mode | stat.S_IEXEC)
+    return path
+
+
+class TestFindDriverBinary:
+    def test_env_var_override_wins(self, monkeypatch):
+        monkeypatch.setenv("WABOT_CHROMEDRIVER", "/custom/chromedriver")
+        assert find_driver_binary("chromium") == "/custom/chromedriver"
+
+    def test_path_lookup(self, monkeypatch, stub_driver):
+        monkeypatch.delenv("WABOT_CHROMEDRIVER", raising=False)
+        monkeypatch.setenv("PATH", str(stub_driver.parent))
+        assert find_driver_binary("chromium") == str(stub_driver)
+
+
+class TestManagedService:
+    def test_spawns_detached_and_answers_status(self, stub_driver, tmp_path):
+        svc = ManagedService("chromium", log_dir=tmp_path, driver_binary=str(stub_driver))
+        url = svc.ensure_running()
+        try:
+            assert service_alive(url)
+            assert svc.pid is not None and svc.port is not None
+            assert url == f"http://127.0.0.1:{svc.port}"
+            # detached: the spawned process is in its own session, so it
+            # would survive this python process exiting
+            assert os.getsid(svc.pid) != os.getsid(os.getpid())
+            assert (tmp_path / f"chromedriver-{svc.port}.log").exists()
+        finally:
+            stop_service(svc.pid)
+
+    def test_startup_timeout_raises(self, tmp_path):
+        # /bin/true exits immediately and never serves /status
+        svc = ManagedService(
+            "chromium", log_dir=tmp_path, driver_binary="/bin/true", startup_timeout=1.0
+        )
+        with pytest.raises(TimeoutError, match="did not answer /status"):
+            svc.ensure_running()
+
+
+class TestStopService:
+    def test_stops_a_live_process_and_reports_dead_ones(self, stub_driver, tmp_path):
+        svc = ManagedService("chromium", log_dir=tmp_path, driver_binary=str(stub_driver))
+        svc.ensure_running()
+        assert stop_service(svc.pid) is True
+        deadline = time.monotonic() + 5
+        while time.monotonic() < deadline:
+            try:
+                os.kill(svc.pid, 0)
+            except ProcessLookupError:
+                break
+            time.sleep(0.05)
+        assert stop_service(999999) is False  # no such pid