fix: hide context exception details (#111)

src/main.py

@@ -18,6 +18,10 @@ EVENT_STREAM_TIMEOUT_SECONDS = 5.0
 READINESS_TIMEOUT_SECONDS = 5.0
 FRONTEND_DIR = Path(__file__).resolve().parent.parent / "frontend"
 
+
+class ContextPayloadError(ValueError):
+    """Raised when Gitea returns a structurally invalid context payload."""
+
 app.add_middleware(
     CORSMiddleware,
     allow_origins=["*"],
@@ -86,20 +90,25 @@ async def context() -> JSONResponse:
             timeout=CONTEXT_TIMEOUT_SECONDS,
         )
         if not isinstance(user_data, dict):
-            raise ValueError("Gitea current-user response was not an object")
+            raise ContextPayloadError("Gitea current-user response was not an object")
         if not all(field in user_data for field in ("id", "login")):
-            raise ValueError("Gitea current-user response did not include id and login")
+            raise ContextPayloadError(
+                "Gitea current-user response did not include id and login"
+            )
         if any(
             data is not None and not isinstance(data, list)
             for data in (repo_data, issues_data, prs_data)
         ):
-            raise ValueError("Gitea collection response was not a list")
+            raise ContextPayloadError("Gitea collection response was not a list")
     except Exception as e:
-        error_message = (
-            f"Gitea context request timed out after {CONTEXT_TIMEOUT_SECONDS:g}s"
-            if isinstance(e, TimeoutError)
-            else str(e)
-        )
+        if isinstance(e, TimeoutError):
+            error_message = (
+                f"Gitea context request timed out after {CONTEXT_TIMEOUT_SECONDS:g}s"
+            )
+        elif isinstance(e, ContextPayloadError):
+            error_message = str(e)
+        else:
+            error_message = "Gitea context is temporarily unavailable"
         return JSONResponse({
             "user": {"id": None, "login": "timmy", "full_name": "Timmy Jr", "email": ""},
             "repos": [],

tests/test_context_timeout.py

@@ -34,6 +34,27 @@ async def test_context_returns_fallback_when_gitea_exceeds_deadline(monkeypatch)
     assert cancelled.is_set()
 
 
+@pytest.mark.anyio
+async def test_context_hides_upstream_exception_details(monkeypatch):
+    async def failing_user():
+        raise RuntimeError("connection refused by secret.internal.example")
+
+    async def empty_collection():
+        return []
+
+    monkeypatch.setattr(main, "current_user", failing_user)
+    monkeypatch.setattr(main, "repos", empty_collection)
+    monkeypatch.setattr(main, "issues", empty_collection)
+    monkeypatch.setattr(main, "pull_requests", empty_collection)
+
+    response = await main.context()
+    body = bytes(response.body)
+    context = json.loads(body)
+
+    assert context["error"] == "Gitea context is temporarily unavailable"
+    assert b"secret.internal.example" not in body
+
+
 @pytest.mark.anyio
 async def test_context_normalizes_nullable_issue_collections(monkeypatch):
     async def user():