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Fix PR base branch update on merge conflicts #18

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Merged
Phlogistique merged 1 commit into from
Dec 26, 2025
Merged

Fix PR base branch update on merge conflicts #18

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8 changes: 5 additions & 3 deletions README.md
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Original file line number Diff line number Diff line change
Expand Up @@ -29,14 +29,16 @@ When a merge conflict occurs during the automatic update:

1. The action posts a comment on the affected PR with instructions for manual resolution
2. Adds a `autorestack-needs-conflict-resolution` label to the PR
3. Updates the PR's base branch (but doesn't push the conflicted state)
3. Keeps the PR's base branch unchanged (so the diff stays readable)
4. Keeps the merged branch around (so you can reference it during resolution)

After you manually resolve the conflict and push:

1. The push triggers the `synchronize` event
2. The action detects the conflict label and removes it
3. Posts a confirmation comment
4. Continues updating any dependent PRs in the stack
3. Updates the PR's base branch to trunk
4. Deletes the old base branch (if no other conflicted PRs still depend on it)
5. Continues updating any dependent PRs in the stack

---

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275 changes: 253 additions & 22 deletions tests/test_e2e.sh
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Original file line number Diff line number Diff line change
Expand Up @@ -58,12 +58,13 @@
# - Does NOT push any conflicted state to the remote
# - Posts a comment on PR3 explaining the conflict
# - Adds a label "autorestack-needs-conflict-resolution" to PR3
# - Updates PR3's base branch to main (even though merge failed)
# - Does NOT update PR3's base branch (keeps it as feature2 for readable diff)
# - Does NOT delete feature2 branch (still referenced by conflicted PR)
# - Exits with success (conflict is handled gracefully, not a failure)
#
# Verifications:
# - feature2 branch is deleted from remote
# - PR3 base branch is updated to main
# - feature2 branch is NOT deleted from remote (still referenced by conflicted PR3)
# - PR3 base branch stays as feature2 (not updated to main)
# - Conflict comment exists on PR3
# - Conflict label "autorestack-needs-conflict-resolution" exists on PR3
# - feature3 branch was NOT updated (still at pre-conflict SHA)
Expand All @@ -74,8 +75,10 @@
# - Push the resolved branch
# - The push triggers the 'synchronize' event on PR3
# - The action detects the conflict label and removes it
# - Updates PR3's base branch to main
# - Deletes feature2 branch (no other conflicted PRs depend on it)
# - The continuation workflow updates feature4 (grandchild) recursively
# - Verify the label is removed, resolution comment is posted, and feature4 is updated
# - Verify the label is removed, base updated, branch deleted, and feature4 is updated
#
# Grandchild Update (feature4):
# - Tests that update_branch_recursive properly handles grandchildren
Expand Down Expand Up @@ -676,23 +679,23 @@ fi
# 11. Verification for Conflict Scenario
echo >&2 "11. Verifying the results of the conflict scenario..."
echo >&2 "Fetching latest state from remote..."
log_cmd git fetch origin --prune # Prune deleted branch feature2
log_cmd git fetch origin --prune

# Verify feature2 branch was deleted remotely
# Verify feature2 branch was NOT deleted (still referenced by conflicted PR3)
if git show-ref --verify --quiet refs/remotes/origin/feature2; then
echo >&2 "❌ Verification Failed: Remote branch 'origin/feature2' still exists after merge."
exit 1
echo >&2 "✅ Verification Passed: Remote branch 'origin/feature2' still exists (kept for conflicted PR)."
else
echo >&2 "✅ Verification Passed: Remote branch 'origin/feature2' was deleted."
echo >&2 "❌ Verification Failed: Remote branch 'origin/feature2' was deleted prematurely."
exit 1
fi

# Verify PR3 base branch was updated to main (action updates base even on conflict)
# Verify PR3 base branch was NOT updated (stays as feature2 for readable diff)
echo >&2 "Checking PR #$PR3_NUM base branch..."
PR3_BASE_AFTER_CONFLICT=$(log_cmd gh pr view "$PR3_NUM" --repo "$REPO_FULL_NAME" --json baseRefName --jq .baseRefName)
if [[ "$PR3_BASE_AFTER_CONFLICT" == "main" ]]; then
echo >&2 "✅ Verification Passed: PR #$PR3_NUM base branch updated to 'main'."
if [[ "$PR3_BASE_AFTER_CONFLICT" == "feature2" ]]; then
echo >&2 "✅ Verification Passed: PR #$PR3_NUM base branch stays as 'feature2' (not updated during conflict)."
else
echo >&2 "❌ Verification Failed: PR #$PR3_NUM base branch is '$PR3_BASE_AFTER_CONFLICT', expected 'main'."
echo >&2 "❌ Verification Failed: PR #$PR3_NUM base branch is '$PR3_BASE_AFTER_CONFLICT', expected 'feature2'."
exit 1
fi

Expand Down Expand Up @@ -789,19 +792,26 @@ else
exit 1
fi

# Verify resolution acknowledgement comment exists on PR3
echo >&2 "Checking for resolution acknowledgement comment on PR #$PR3_NUM..."
RESOLUTION_COMMENT=$(log_cmd gh pr view "$PR3_URL" --repo "$REPO_FULL_NAME" --json comments --jq '.comments[] | select(.body | contains("Conflict resolved")) | .body')
if [[ -n "$RESOLUTION_COMMENT" ]]; then
echo >&2 "✅ Verification Passed: Resolution acknowledgement comment found on PR #$PR3_NUM."
# Verify PR3 base branch was updated to main after resolution
echo >&2 "Checking PR #$PR3_NUM base branch after resolution..."
PR3_BASE_AFTER_RESOLUTION=$(log_cmd gh pr view "$PR3_NUM" --repo "$REPO_FULL_NAME" --json baseRefName --jq .baseRefName)
if [[ "$PR3_BASE_AFTER_RESOLUTION" == "main" ]]; then
echo >&2 "✅ Verification Passed: PR #$PR3_NUM base branch updated to 'main' after resolution."
else
echo >&2 "❌ Verification Failed: Resolution acknowledgement comment not found on PR #$PR3_NUM."
echo >&2 "--- Comments on PR #$PR3_NUM ---"
gh pr view "$PR3_URL" --repo "$REPO_FULL_NAME" --json comments --jq '.comments[].body' || echo "Failed to get comments"
echo >&2 "-----------------------------"
echo >&2 "❌ Verification Failed: PR #$PR3_NUM base branch is '$PR3_BASE_AFTER_RESOLUTION', expected 'main'."
exit 1
fi

# Verify feature2 was deleted after resolution (no other conflicted PRs depend on it)
echo >&2 "Checking that feature2 branch was deleted after resolution..."
log_cmd git fetch origin --prune
if git show-ref --verify --quiet refs/remotes/origin/feature2; then
echo >&2 "❌ Verification Failed: Remote branch 'origin/feature2' still exists after resolution."
exit 1
else
echo >&2 "✅ Verification Passed: Remote branch 'origin/feature2' was deleted after resolution."
fi

echo >&2 "--- Continuation Workflow Test Completed Successfully ---"

# 15. Verify conflict resolution (content checks)
Expand Down Expand Up @@ -863,6 +873,227 @@ fi
echo >&2 "--- Conflict Scenario Test Completed Successfully ---"


# --- SCENARIO 3: Sibling Conflicts (Multiple PRs from same base, both conflict) ---
# ===================================================================================
# Tests that the old base branch is kept until ALL sibling PRs resolve their conflicts.
#
# Setup:
# - Create a new stack: main <- feature5 <- (feature6, feature7) parallel children
# - feature6 and feature7 both modify line 5 of file.txt
# - main modifies line 5 differently (creating conflict with both siblings)
#
# Expected Behavior:
# - After merging feature5, both feature6 and feature7 have conflicts
# - feature5 branch is kept (referenced by both conflicted PRs)
# - After resolving feature6, feature5 is still kept (feature7 still conflicted)
# - After resolving feature7, feature5 is deleted (no more conflicted siblings)
# ===================================================================================

echo >&2 "--- Testing Sibling Conflicts Scenario ---"

# 16. Create new stack for sibling conflict test
echo >&2 "16. Creating new stack for sibling conflict test..."
log_cmd git checkout main
log_cmd git pull origin main

# Create feature5 based on main (modifies line 2, no conflict with line 5)
log_cmd git checkout -b feature5 main
sed -i '2s/.*/Feature 5 content line 2/' file.txt
log_cmd git add file.txt
log_cmd git commit -m "Add feature 5"
log_cmd git push origin feature5
PR5_URL=$(log_cmd gh pr create --repo "$REPO_FULL_NAME" --base main --head feature5 --title "Feature 5" --body "This is PR 5")
PR5_NUM=$(echo "$PR5_URL" | awk -F'/' '{print $NF}')
echo >&2 "Created PR #$PR5_NUM: $PR5_URL"

# Create feature6 based on feature5 (modifies line 5, will conflict with main)
log_cmd git checkout -b feature6 feature5
sed -i '5s/.*/Feature 6 conflicting content line 5/' file.txt
log_cmd git add file.txt
log_cmd git commit -m "Add feature 6 (modifies line 5)"
log_cmd git push origin feature6
PR6_URL=$(log_cmd gh pr create --repo "$REPO_FULL_NAME" --base feature5 --head feature6 --title "Feature 6" --body "This is PR 6, sibling of PR 7")
PR6_NUM=$(echo "$PR6_URL" | awk -F'/' '{print $NF}')
echo >&2 "Created PR #$PR6_NUM: $PR6_URL"

# Create feature7 based on feature5 (also modifies line 5, will conflict with main)
log_cmd git checkout feature5
log_cmd git checkout -b feature7
sed -i '5s/.*/Feature 7 conflicting content line 5/' file.txt
log_cmd git add file.txt
log_cmd git commit -m "Add feature 7 (also modifies line 5)"
log_cmd git push origin feature7
PR7_URL=$(log_cmd gh pr create --repo "$REPO_FULL_NAME" --base feature5 --head feature7 --title "Feature 7" --body "This is PR 7, sibling of PR 6")
PR7_NUM=$(echo "$PR7_URL" | awk -F'/' '{print $NF}')
echo >&2 "Created PR #$PR7_NUM: $PR7_URL"

# Introduce conflicting change on main (line 5) - this will conflict with feature6/7
# when the action tries to merge SQUASH_COMMIT~ into them
log_cmd git checkout main
sed -i '5s/.*/Main conflicting content line 5/' file.txt
log_cmd git add file.txt
log_cmd git commit -m "Add conflicting change on main line 5"
log_cmd git push origin main

# 17. Merge feature5 to trigger conflicts on both siblings
echo >&2 "17. Squash merging PR #$PR5_NUM (feature5) to trigger sibling conflicts..."
merge_pr_with_retry "$PR5_URL"
MERGE_COMMIT_SHA5=$(gh pr view "$PR5_URL" --repo "$REPO_FULL_NAME" --json mergeCommit -q .mergeCommit.oid)
echo >&2 "PR #$PR5_NUM merged. Squash commit SHA: $MERGE_COMMIT_SHA5"

# Wait for workflow
echo >&2 "Waiting for workflow..."
if ! wait_for_workflow "$PR5_NUM" "feature5" "$MERGE_COMMIT_SHA5" "success"; then
echo >&2 "Workflow for PR5 merge did not complete successfully."
exit 1
fi

# 18. Verify both siblings have conflicts and feature5 is kept
echo >&2 "18. Verifying sibling conflict state..."
log_cmd git fetch origin

# Verify feature5 branch was NOT deleted (both siblings conflicted)
if git show-ref --verify --quiet refs/remotes/origin/feature5; then
echo >&2 "✅ Verification Passed: Remote branch 'origin/feature5' still exists (kept for conflicted siblings)."
else
echo >&2 "❌ Verification Failed: Remote branch 'origin/feature5' was deleted prematurely."
exit 1
fi

# Verify both PRs have conflict labels
PR6_HAS_LABEL=$(gh pr view "$PR6_URL" --repo "$REPO_FULL_NAME" --json labels --jq '.labels[] | select(.name == "autorestack-needs-conflict-resolution") | .name')
PR7_HAS_LABEL=$(gh pr view "$PR7_URL" --repo "$REPO_FULL_NAME" --json labels --jq '.labels[] | select(.name == "autorestack-needs-conflict-resolution") | .name')

if [[ "$PR6_HAS_LABEL" == "autorestack-needs-conflict-resolution" ]]; then
echo >&2 "✅ Verification Passed: PR #$PR6_NUM has conflict label."
else
echo >&2 "❌ Verification Failed: PR #$PR6_NUM does not have conflict label."
exit 1
fi

if [[ "$PR7_HAS_LABEL" == "autorestack-needs-conflict-resolution" ]]; then
echo >&2 "✅ Verification Passed: PR #$PR7_NUM has conflict label."
else
echo >&2 "❌ Verification Failed: PR #$PR7_NUM does not have conflict label."
exit 1
fi

# Verify both PRs still have feature5 as base
PR6_BASE=$(gh pr view "$PR6_NUM" --repo "$REPO_FULL_NAME" --json baseRefName --jq .baseRefName)
PR7_BASE=$(gh pr view "$PR7_NUM" --repo "$REPO_FULL_NAME" --json baseRefName --jq .baseRefName)

if [[ "$PR6_BASE" == "feature5" && "$PR7_BASE" == "feature5" ]]; then
echo >&2 "✅ Verification Passed: Both sibling PRs still have 'feature5' as base."
else
echo >&2 "❌ Verification Failed: PR6 base is '$PR6_BASE', PR7 base is '$PR7_BASE', expected both to be 'feature5'."
exit 1
fi

# 19. Resolve first sibling (feature6) - feature5 should still be kept
echo >&2 "19. Resolving first sibling (feature6)..."
log_cmd git checkout feature6
log_cmd git fetch origin
if git merge origin/main; then
echo >&2 "Merge succeeded unexpectedly (no conflict?)"
else
echo >&2 "Resolving conflict on feature6..."
log_cmd git checkout --ours file.txt
log_cmd git add file.txt
log_cmd git commit --no-edit
fi
log_cmd git push origin feature6

# Wait for continuation workflow
echo >&2 "Waiting for continuation workflow for feature6..."
if ! wait_for_synchronize_workflow "$PR6_NUM" "feature6" "success"; then
echo >&2 "Continuation workflow for feature6 did not complete successfully."
exit 1
fi

# 20. Verify feature5 is still kept (feature7 still conflicted)
echo >&2 "20. Verifying feature5 is still kept after first sibling resolution..."
log_cmd git fetch origin

# feature5 should still exist
if git show-ref --verify --quiet refs/remotes/origin/feature5; then
echo >&2 "✅ Verification Passed: Remote branch 'origin/feature5' still exists (feature7 still conflicted)."
else
echo >&2 "❌ Verification Failed: Remote branch 'origin/feature5' was deleted prematurely (feature7 still needs it)."
exit 1
fi

# PR6 base should now be main
PR6_BASE_AFTER=$(gh pr view "$PR6_NUM" --repo "$REPO_FULL_NAME" --json baseRefName --jq .baseRefName)
if [[ "$PR6_BASE_AFTER" == "main" ]]; then
echo >&2 "✅ Verification Passed: PR #$PR6_NUM base updated to 'main' after resolution."
else
echo >&2 "❌ Verification Failed: PR #$PR6_NUM base is '$PR6_BASE_AFTER', expected 'main'."
exit 1
fi

# PR6 should no longer have conflict label
PR6_LABEL_AFTER=$(gh pr view "$PR6_URL" --repo "$REPO_FULL_NAME" --json labels --jq '.labels[] | select(.name == "autorestack-needs-conflict-resolution") | .name')
if [[ -z "$PR6_LABEL_AFTER" ]]; then
echo >&2 "✅ Verification Passed: PR #$PR6_NUM conflict label removed."
else
echo >&2 "❌ Verification Failed: PR #$PR6_NUM still has conflict label."
exit 1
fi

# PR7 should still have conflict label and feature5 as base
PR7_LABEL_STILL=$(gh pr view "$PR7_URL" --repo "$REPO_FULL_NAME" --json labels --jq '.labels[] | select(.name == "autorestack-needs-conflict-resolution") | .name')
PR7_BASE_STILL=$(gh pr view "$PR7_NUM" --repo "$REPO_FULL_NAME" --json baseRefName --jq .baseRefName)
if [[ "$PR7_LABEL_STILL" == "autorestack-needs-conflict-resolution" && "$PR7_BASE_STILL" == "feature5" ]]; then
echo >&2 "✅ Verification Passed: PR #$PR7_NUM still has conflict label and 'feature5' base."
else
echo >&2 "❌ Verification Failed: PR7 label='$PR7_LABEL_STILL', base='$PR7_BASE_STILL'."
exit 1
fi

# 21. Resolve second sibling (feature7) - now feature5 should be deleted
echo >&2 "21. Resolving second sibling (feature7)..."
log_cmd git checkout feature7
log_cmd git fetch origin
if git merge origin/main; then
echo >&2 "Merge succeeded unexpectedly (no conflict?)"
else
echo >&2 "Resolving conflict on feature7..."
log_cmd git checkout --ours file.txt
log_cmd git add file.txt
log_cmd git commit --no-edit
fi
log_cmd git push origin feature7

# Wait for continuation workflow
echo >&2 "Waiting for continuation workflow for feature7..."
if ! wait_for_synchronize_workflow "$PR7_NUM" "feature7" "success"; then
echo >&2 "Continuation workflow for feature7 did not complete successfully."
exit 1
fi

# 22. Verify feature5 is now deleted (all siblings resolved)
echo >&2 "22. Verifying feature5 is deleted after all siblings resolved..."
log_cmd git fetch origin --prune

if git show-ref --verify --quiet refs/remotes/origin/feature5; then
echo >&2 "❌ Verification Failed: Remote branch 'origin/feature5' still exists after all siblings resolved."
exit 1
else
echo >&2 "✅ Verification Passed: Remote branch 'origin/feature5' was deleted after all siblings resolved."
fi

# PR7 base should now be main
PR7_BASE_FINAL=$(gh pr view "$PR7_NUM" --repo "$REPO_FULL_NAME" --json baseRefName --jq .baseRefName)
if [[ "$PR7_BASE_FINAL" == "main" ]]; then
echo >&2 "✅ Verification Passed: PR #$PR7_NUM base updated to 'main' after resolution."
else
echo >&2 "❌ Verification Failed: PR #$PR7_NUM base is '$PR7_BASE_FINAL', expected 'main'."
exit 1
fi

echo >&2 "--- Sibling Conflicts Scenario Test Completed Successfully ---"


# --- Test Succeeded ---
echo >&2 "--- E2E Test Completed Successfully! ---"

Expand Down
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