fix: service_alive returns False for non-HTTP responders

docs/superpowers/plans/2026-07-07-wabot-modernization.md

@@ -657,6 +657,7 @@ def status_server():
     thread.start()
     yield f"http://127.0.0.1:{server.server_address[1]}"
     server.shutdown()
+    server.server_close()
 
 
 class TestServiceAlive:
@@ -683,6 +684,33 @@ class TestExternalServer:
     def test_raises_when_dead(self):
         with pytest.raises(ConnectionError, match="no WebDriver server"):
             ExternalServer("http://127.0.0.1:1").ensure_running()
+
+
+class TestServiceAliveNonHttpResponder:
+    def test_non_http_service_on_port_is_false_and_clean_error(self):
+        # wrong-port misconfiguration: some non-HTTP service answers the socket
+        import socket
+
+        server = socket.create_server(("127.0.0.1", 0))
+        port = server.getsockname()[1]
+
+        def answer(count=2):
+            for _ in range(count):
+                try:
+                    conn, _ = server.accept()
+                except OSError:
+                    return
+                conn.sendall(b"SSH-2.0-OpenSSH_9.7\r\n")
+                conn.close()
+
+        thread = threading.Thread(target=answer, daemon=True)
+        thread.start()
+        try:
+            assert service_alive(f"http://127.0.0.1:{port}", timeout=2.0) is False
+            with pytest.raises(ConnectionError, match="no WebDriver server"):
+                ExternalServer(f"http://127.0.0.1:{port}").ensure_running()
+        finally:
+            server.close()
 ```
 
 - [ ] **Step 2: Run tests to verify they fail**
@@ -705,6 +733,7 @@ Selenium Grid or standalone driver the user runs) and ``ManagedService``
 
 from __future__ import annotations
 
+import http.client
 import json
 import logging
 import urllib.request
@@ -764,12 +793,13 @@ def service_alive(url: str, timeout: float = 2.0) -> bool:
 
     Liveness only: geckodriver reports ready=false while its single session
     is in use, so the ``ready`` flag is deliberately ignored.
+    The ``timeout`` bounds each socket operation, not total wall-clock time.
     """
     try:
         with urllib.request.urlopen(f"{url.rstrip('/')}/status", timeout=timeout) as resp:
             json.loads(resp.read())
             return resp.status == 200
-    except (OSError, ValueError):
+    except (OSError, ValueError, http.client.HTTPException):
         return False
 
 
@@ -788,7 +818,7 @@ class ExternalServer:
 - [ ] **Step 4: Run tests to verify they pass**
 
 Run: `uv run pytest tests/unit/test_hosts.py -v`
-Expected: 12 passed
+Expected: 13 passed
 
 - [ ] **Step 5: Commit**
 
@@ -898,6 +928,7 @@ Expected: new tests FAIL — `ImportError: cannot import name 'ManagedService'`;
 Append to `src/wabot/hosts.py`, and extend the top import block to:
 
 ```python
+import http.client
 import json
 import logging
 import os
@@ -1006,7 +1037,7 @@ def stop_service(pid: int) -> bool:
 - [ ] **Step 4: Run tests to verify they pass**
 
 Run: `uv run pytest tests/unit/test_hosts.py -v`
-Expected: 17 passed (12 from Task 4 + 5 new)
+Expected: 18 passed (13 from Task 4 + 5 new)
 
 - [ ] **Step 5: Commit**
 
@@ -1142,7 +1173,7 @@ Run: `uv run pytest tests/unit/test_reattach.py -v`
 Expected: 5 passed
 
 Run: `uv run pytest`
-Expected: all unit tests so far pass (pacing 7, sessions 14, hosts 17, reattach 5 = 43)
+Expected: all unit tests so far pass (pacing 7, sessions 14, hosts 18, reattach 5 = 44)
 
 - [ ] **Step 5: Commit**
 
@@ -2667,7 +2698,7 @@ Run: `uv run pytest tests/unit/test_api.py -v`
 Expected: 11 passed
 
 Run: `uv run pytest`
-Expected: full unit suite passes (104 tests: pacing 7, sessions 14, hosts 17, reattach 5, fields 11, page 23, screenshot 3, browser 13, api 11)
+Expected: full unit suite passes (105 tests: pacing 7, sessions 14, hosts 18, reattach 5, fields 11, page 23, screenshot 3, browser 13, api 11)
 
 - [ ] **Step 5: Commit**
 

src/wabot/hosts.py

@@ -8,6 +8,7 @@ Selenium Grid or standalone driver the user runs) and ``ManagedService``
 
 from __future__ import annotations
 
+import http.client
 import json
 import logging
 import urllib.request
@@ -67,12 +68,13 @@ def service_alive(url: str, timeout: float = 2.0) -> bool:
 
     Liveness only: geckodriver reports ready=false while its single session
     is in use, so the ``ready`` flag is deliberately ignored.
+    The ``timeout`` bounds each socket operation, not total wall-clock time.
     """
     try:
         with urllib.request.urlopen(f"{url.rstrip('/')}/status", timeout=timeout) as resp:
             json.loads(resp.read())
             return resp.status == 200
-    except (OSError, ValueError):
+    except (OSError, ValueError, http.client.HTTPException):
         return False
 
 

tests/unit/test_hosts.py

@@ -65,6 +65,7 @@ def status_server():
     thread.start()
     yield f"http://127.0.0.1:{server.server_address[1]}"
     server.shutdown()
+    server.server_close()
 
 
 class TestServiceAlive:
@@ -91,3 +92,30 @@ class TestExternalServer:
     def test_raises_when_dead(self):
         with pytest.raises(ConnectionError, match="no WebDriver server"):
             ExternalServer("http://127.0.0.1:1").ensure_running()
+
+
+class TestServiceAliveNonHttpResponder:
+    def test_non_http_service_on_port_is_false_and_clean_error(self):
+        # wrong-port misconfiguration: some non-HTTP service answers the socket
+        import socket
+
+        server = socket.create_server(("127.0.0.1", 0))
+        port = server.getsockname()[1]
+
+        def answer(count=2):
+            for _ in range(count):
+                try:
+                    conn, _ = server.accept()
+                except OSError:
+                    return
+                conn.sendall(b"SSH-2.0-OpenSSH_9.7\r\n")
+                conn.close()
+
+        thread = threading.Thread(target=answer, daemon=True)
+        thread.start()
+        try:
+            assert service_alive(f"http://127.0.0.1:{port}", timeout=2.0) is False
+            with pytest.raises(ConnectionError, match="no WebDriver server"):
+                ExternalServer(f"http://127.0.0.1:{port}").ensure_running()
+        finally:
+            server.close()