Fuchsia's Gerrit code review site supports an automatic change submission feature. Any change that is opted in will automatically be submitted after being approved and passing presubmit checks.
Note: Auto-submit is a Fuchsia-specific feature and its use and behavior do not generalize to other Gerrit hosts, such as Chromium and Android, that use Commit Queue or have their own auto-submit functionality.
When adding reviewers in the Gerrit UI using the REPLY dialog, select the +1 for the Fuchsia-Auto-Submit label.
After your change meets all the submit requirements (generally a Code-Review +2 vote and owner approval of all affected files), the auto-submit bot will apply the Commit-Queue +2 label. Once all presubmit checks pass, your change will automatically be submitted.
If you want your change to land as soon as possible after approval, it‘s recommended that you set Commit-Queue +1 before (or at the same time as) sending your change for review. When auto-submit applies the Commit-Queue +2 label, it will skip rerunning any checks that have already passed within the last 24 hours, so submission often doesn’t need to wait for checks to rerun.
Auto-submit is implemented as a cron job that runs every 10 minutes, so it may take up to 10 minutes for Commit-Queue +2 to be applied to your change after being approved.
If the author of a change has opted into auto-submit, a Fuchsia-Auto-Submit +1 tile will appear under Trigger Votes in the left column of the Gerrit UI.
If you leave unresolved comments at the time you grant Code-Review +2, the auto-submit bot will not submit the change until all comments are resolved.
However, the change author can still manually set Commit-Queue +2 to submit the change. If you think the change should not be submitted, then it's recommended that either you withhold Code-Review +2 or, if another reviewer has already approved the change, set Code-Review -2.
This happens when the change had implicit Code-Owners approval as a result of you (the change uploader) owning the affected files. Either rebase your change locally on the main branch and re-upload, or click REBASE in the Gerrit UI.
When working with stacks of changes, Gerrit will sometimes incorrectly consider a change to have a merge conflict after its parent change is submitted, in which case it will not be submittable.
As a workaround, the auto-submit bot rebases a change on top of the main branch when it detects a spurious merge conflict. This fixes the conflict but also results in the bot taking over the change, removing the implicit Code-Owners approval of the change uploader.
When you upload a new patchset by rebasing you take back ownership of the change, restoring your implicit Code-Owners approval.
