fix: Display error message on the front end after PR summary interface call fails

gitlab_bot.py

@@ -153,19 +153,28 @@ async def note_issue_event(event, gl, *args, **kwargs):
 @bot.router.register("Merge Request Hook", action="open")
 async def merge_request_opened_event(event, gl, *args, **kwargs):
     if not ignore_event(event):
-        await merge_request_hooks.merge_request_opened_event(event, gl, args, kwargs)
+        try:
+            await merge_request_hooks.merge_request_opened_event(event, gl, args, kwargs)
+        except Exception as exc:
+            await _post_merge_request_error_note(event, gl, exc)
 
 
 @bot.router.register("Merge Request Hook", action="update")
 async def merge_request_updated_event(event, gl, *args, **kwargs):
     if not ignore_event(event):
-        await merge_request_hooks.merge_request_updated_event(event, gl, args, kwargs)
+        try:
+            await merge_request_hooks.merge_request_updated_event(event, gl, args, kwargs)
+        except Exception as exc:
+            await _post_merge_request_error_note(event, gl, exc)
 
 
 @bot.router.register("Merge Request Hook", action="reopen")
 async def merge_request_reopen_event(event, gl, *args, **kwargs):
     if not ignore_event(event):
-        await merge_request_hooks.merge_request_reopen_event(event, gl, args, kwargs)
+        try:
+            await merge_request_hooks.merge_request_reopen_event(event, gl, args, kwargs)
+        except Exception as exc:
+            await _post_merge_request_error_note(event, gl, exc)
 
 
 @bot.router.register("Merge Request Hook", action="approved")
@@ -218,6 +227,34 @@ def ignore_event(event) -> bool:
         return True
 
 
+async def _post_merge_request_error_note(event, gl, exc):
+    data = getattr(event, "data", {}) or {}
+    project = data.get("project") or {}
+    project_id = project.get("id") if isinstance(project, dict) else None
+    attributes = data.get("object_attributes") or {}
+    mr_iid = attributes.get("iid") if isinstance(attributes, dict) else None
+    if mr_iid is None:
+        merge_request = data.get("merge_request") or {}
+        mr_iid = merge_request.get("iid") if isinstance(merge_request, dict) else None
+    if project_id is None or mr_iid is None:
+        logging.error(
+            "Unable to post merge request error note (project_id=%s, mr_iid=%s): %s",
+            project_id,
+            mr_iid,
+            exc,
+        )
+        return
+    post = getattr(gl, "post", None)
+    if post is None:
+        logging.error("Unable to post merge request error note: GitLab API client unavailable: %s", exc)
+        return
+    body = f"PR summary interface call failed: {exc}"
+    try:
+        await post(f"/projects/{project_id}/merge_requests/{mr_iid}/notes", data={"body": body})
+    except Exception:
+        logging.error("Unable to post merge request error note: %s", exc, exc_info=True)
+
+
 if __name__ == "__main__":
     logging.basicConfig(level=logging.INFO)
     bot.run(host=bot_host, port=int(bot_port))