refactor(tests+frontend): one http_sink helper for the hook tests; apiErrorMessage replaces ten hand-rolled error-body parses; type X, import specifiers are not definitions (#2904, milestone 299 step 6)

tests/helpers.http_sink replaces three module-local _Sink handlers (the
write-path tests and the after-write test). ProjectView + SettingsView
parsed `(e as {body?:{error?}}).body?.error || fallback` by hand ten times
beside the apiErrorMessage canon (#2853) - all ten now call it. The
extractor (server + the hook awk mirror) no longer reads `import { type Foo }`
as a definition of Foo - that was the last "identical body" sym family.

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

tests/test_write_path_trigger.py

@@ -13,7 +13,7 @@ from pathlib import Path
 from unittest.mock import AsyncMock, MagicMock, patch
 
 import pytest
-from tests.helpers import fake_note
+from tests.helpers import fake_note, http_sink
 
 PLUGIN = Path(__file__).resolve().parents[1] / "plugin"
 HOOK = PLUGIN / "hooks" / "scribe_prior_art.sh"
@@ -1149,6 +1149,23 @@ def test_route_stamps_only_for_a_caller_allowed_to_write():
     assert "&shapes=" in hook
 
 
+def test_hook_does_not_name_a_type_import_specifier_as_a_shape(tmp_path):
+    """#2904, the awk mirror of the server rule: `type Foo,` inside an import
+    list is not a definition; `type Baz = …` on its own line is."""
+    env = _hook_runtime_env()
+    repo = tmp_path / "repo"
+    repo.mkdir()
+    subprocess.run(["git", "init", "-q"], cwd=repo, check=True, env=env)
+    seen = _run_hook_against_sink(tmp_path, {
+        "session_id": "s-type", "cwd": str(repo), "tool_name": "Write",
+        "tool_input": {"file_path": str(repo / "x.ts"),
+                       "content": 'import { type Foo, bar } from "./y";\n'
+                                  "type Baz = { a: number };\n"
+                                  "export function use(): Baz {\n  return { a: 1 };\n}\n"},
+    })
+    assert seen["shapes"] == ["sym:Baz,sym:use"]
+
+
 def test_hook_names_the_shapes_being_written():
     """The feed's two inputs: every definition in the payload, or — for an Edit
     that changes a body, not a signature — the definition enclosing the edit,
@@ -1165,39 +1182,15 @@ def test_hook_names_the_shapes_being_written():
 
 def _run_hook_against_sink(tmp_path, payload):
     """Run the hook with SCRIBE_URL pointed at a throwaway local listener and
-    return the query the hook sent. Lets the shell be tested end to end —
-    the extraction, the encoding, the URL — without a Scribe instance."""
-    import http.server
-    import threading
-    import urllib.parse
-
-    seen: dict = {}
-
-    class _Sink(http.server.BaseHTTPRequestHandler):
-        def do_GET(self):
-            seen.update(urllib.parse.parse_qs(urllib.parse.urlparse(self.path).query))
-            self.send_response(200)
-            self.send_header("Content-Type", "application/json")
-            self.end_headers()
-            self.wfile.write(b'{"context":"","note_ids":[]}')
-
-        def log_message(self, *a):
-            pass
-
-    server = http.server.HTTPServer(("127.0.0.1", 0), _Sink)
-    thread = threading.Thread(target=server.serve_forever, daemon=True)
-    thread.start()
-    try:
-        env = dict(_hook_runtime_env(), SCRIBE_URL=f"http://127.0.0.1:{server.server_port}")
+    return the query the hook sent (tests.helpers.http_sink)."""
+    with http_sink() as (port, seen):
+        env = dict(_hook_runtime_env(), SCRIBE_URL=f"http://127.0.0.1:{port}")
         out = subprocess.run(
             ["bash", str(HOOK)], input=json.dumps(payload),
             capture_output=True, text=True, env=env,
         )
         assert out.returncode == 0, out.stderr
-    finally:
-        server.shutdown()
-        server.server_close()
-    return seen
+    return seen[0] if seen else {}
 
 
 def test_hook_sends_every_definition_in_a_write(tmp_path):
@@ -1321,28 +1314,10 @@ def test_the_hook_keeps_a_derive_channel_and_sends_it_back(tmp_path):
     """#2900: derive keys the server returns land in the session's own
     `.derive.ids` file and go back as `exclude_derive` on the next write —
     a family is named once per session, not at every edit."""
-    import http.server
-    import threading
-    import urllib.parse
-
-    seen: list[dict] = []
-
-    class _Sink(http.server.BaseHTTPRequestHandler):
-        def do_GET(self):
-            seen.append(urllib.parse.parse_qs(urllib.parse.urlparse(self.path).query))
-            self.send_response(200)
-            self.send_header("Content-Type", "application/json")
-            self.end_headers()
-            self.wfile.write(b'{"context":"> family","note_ids":[],"sync_note_ids":[],'
-                             b'"derive_keys":["dup:483a","canon:2855"]}')
-
-        def log_message(self, *a):
-            pass
-
-    server = http.server.HTTPServer(("127.0.0.1", 0), _Sink)
-    threading.Thread(target=server.serve_forever, daemon=True).start()
-    try:
-        env = dict(_hook_runtime_env(), SCRIBE_URL=f"http://127.0.0.1:{server.server_port}",
+    reply = (b'{"context":"> family","note_ids":[],"sync_note_ids":[],'
+             b'"derive_keys":["dup:483a","canon:2855"]}')
+    with http_sink(reply) as (port, seen):
+        env = dict(_hook_runtime_env(), SCRIBE_URL=f"http://127.0.0.1:{port}",
                    TMPDIR=str(tmp_path))
         payload = {"session_id": "s-derive-1", "cwd": str(tmp_path), "tool_name": "Write",
                    "tool_input": {"file_path": str(tmp_path / "a.css"),
@@ -1351,8 +1326,6 @@ def test_the_hook_keeps_a_derive_channel_and_sends_it_back(tmp_path):
             out = subprocess.run(["bash", str(HOOK)], input=json.dumps(payload),
                                  capture_output=True, text=True, env=env)
             assert out.returncode == 0, out.stderr
-    finally:
-        server.shutdown()
     assert "exclude_derive" not in seen[0]
     assert seen[1]["exclude_derive"] == ["dup:483a,canon:2855"]
     state = tmp_path / "scribe-priorart" / "s-derive-1.derive.ids"