Support "squash and merge" in Merge Train
Problem to solve
Currently, Merge Train doesn't allow users to choose squash option. It could be a deal-breaker for some users. We should consider supporting squash and merge.
Intended users
Developers
Permissions and Security
To squash and merge pull requests, you must have write permissions in the repository, and the repository must allow squash merging.
These actions should be logged to audit log
Feature Flag
This feature is implemented behind merge_train_new_stale_check feature flag and enabled by default. Once we've confirmed the feature is deemed stable, we remove the feature flag.
Links and references
MRs:
- Preserve merge train rows after merge !19864 (merged)
- Proactively marking stale status in merge train !19434 (merged)
- Documentation update (https://docs.gitlab.com/ee/ci/merge_request_pipelines/pipelines_for_merged_results/merge_trains/#requirements-and-limitations)