🌸 Cherry pick request for 26484 into 26356 (cherry-picked) #26483
Description
Cherry-pick request
| Issue | PR | Production? | RC? | Release issue |
|---|---|---|---|---|
| #26484 | #26479 | YES | YES | #26356 |
Why does this issue meet the cherry-pick criteria?
This is a production-affecting bug.
Why is a RC cherry-pick not needed?
Not applicable.
Mini-postmortem
TODO: This postmortem will be written after the cherry-pick deployment and before this issue is closed. Delete this TODO when the postmortem is ready.
Summary
We are refactoring several interfaces out from resources service to a mutator service. amp-auto-lightbox uses the API from resources service and was not switched to the new one. It was not caught until on production, and console error log triggered the alarm.
| Users affected | Impact |
|---|---|
| all users using amp-auto-lightbox on prod | partial loss of functionality of amp-auto-lightbox |
Root Causes
-
amp-auto-lightbox uses
element.getResourcesto obtain the service object, and the type checker is not able to find the type reference of that method. The type checker therefore failed to check whether the method call exists. -
There is insufficient traffic for this single extension on canary that would have triggered an alarm.
Action Items
| Action Item | Type | Owner | PR # |
|---|---|---|---|
| #26750 | Prevent | @choumx | #<PR_NUMBER> |
Lessons Learned
Things that went well
- The refactoring itself was splitted into phases, so that the final switch-over PR was not large and easy to be reverted.
Things that went wrong
- Traffic on canary is not large enough for relatively infrequent code paths.
/cc @ampproject/wg-approvers @ampproject/cherry-pick-approvers