Diff suggestion comments duplicated instead of moving with code #230
Description
Diff suggestion comments are sometimes misplaced — duplicated in their original position rather than moving with the associated code when a PR diff shifts.
Symptom
When warden posts a diff suggestion on a PR, if the surrounding code moves (e.g. a block is relocated in a later commit), the suggestion comment is duplicated at the original line instead of following the code it was attached to.
Known facts
- Observed on active PRs where diff suggestions were generated by warden.
- The duplicate appears at the original line position; the moved code does not get the suggestion carried over.
Unknowns
- Whether this is a GitHub API limitation (suggestions are line-anchored, not semantically anchored) or a warden-side issue in how suggestions are constructed.
- Frequency / reproducibility across different PR shapes.
Root-cause hypotheses
- GitHub line-anchoring (high confidence): GitHub's suggestion API anchors comments to a specific line number in the diff. When code moves, the anchor becomes stale and GitHub may render a duplicate or orphaned comment. Warden may not have logic to detect or suppress this.
- Warden re-posts suggestions on diff refresh (medium confidence): If warden re-evaluates the PR after a new commit and re-posts suggestions without deduplication, it would produce duplicate comments.
Next steps
- Audit warden's suggestion posting logic for deduplication guards.
- Confirm whether GitHub's native suggestion API has any semantic-anchor support or if this is inherently positional.