Mk Resolving Merge Conflicts

Resolving Merge Conflicts

Path convention: Commands assume cwd is the repo root ($(git rev-parse --show-toplevel)).

Iron Laws

• Resolve every conflict; do not abandon by default. git merge --abort or git rebase --abort requires explicit user direction. Completing the operation with a commit or git rebase --continue also requires explicit user go-ahead.
• Do not invent new behaviour. Resolution combines existing intents; it is not a place to add features or refactor.

When to Use

• git status shows Unmerged paths / "you have unmerged files"
• A git merge, git rebase, git cherry-pick, or git pull stopped on conflicts
• User says "resolve the conflicts", "fix the rebase", "finish the merge"

Do NOT use when: no operation is in progress (nothing to resolve), or the request is to start a merge/ship from scratch (use mk:ship).

Workflow Integration

Phase: on-demand. Most often fires inside Phase 5 (Ship) when mk:ship merges the base branch and hits conflicts. Hands control back once the working tree is clean and checks pass.

Process

Copy this checklist and track progress:

- [ ] 1. See the current state (operation type + conflicted files)
- [ ] 2. Find the primary sources (why each side changed)
- [ ] 3. Resolve each hunk (preserve both intents)
- [ ] 4. Run the project's automated checks
- [ ] 5. Present resolved state and obtain approval to finish the merge/rebase

1. See the current state

Determine whether a merge or a rebase is in progress — the finish step differs.

git status                                   # human summary + hint line
git diff --name-only --diff-filter=U         # exact conflicted (unmerged) files
ls .git/MERGE_HEAD 2>/dev/null && echo MERGE # present => merge in progress
ls -d .git/rebase-merge .git/rebase-apply 2>/dev/null && echo REBASE
git log --oneline -5 --all --decorate        # orient on recent history

Read every conflicted file. Note each <<<<<<< / ======= / >>>>>>> hunk and which labels mark each side (HEAD/ours vs the incoming branch/commit).

Rebase side-swap: during a rebase ours is the branch being rebased ONTO and theirs is your commit being replayed — the opposite of a merge. Confirm before assuming which side is "yours".

2. Find the primary sources

For each conflict, understand why each change was made — do not guess from the diff alone.

git log --merge -p -- <file>                 # commits touching the conflict on both sides
git log -p <side> -- <file>                  # full history of one side's hunk
gh pr list --state merged --search <term>    # the PR that introduced the change
gh pr view <num> ; gh issue view <num>       # stated intent, linked tickets

Read commit messages, PR descriptions, and linked issues. The goal is the original intent behind each side, not just the textual difference.

3. Resolve each hunk

For every hunk, in order of confidence:

1. Preserve both intents where they are compatible — combine the two changes so neither is lost. This is the default and most common outcome.
2. Where incompatible, pick the side matching the stated goal of the merge/rebase (e.g. "merge feature X into main" → keep X's behaviour) and note the trade-off so the discarded intent is visible to the user.
3. Remove all conflict markers (<<<<<<<, =======, >>>>>>>). Verify none remain: git grep -nE '^(<{7}|={7}|>{7})' -- <files> returns nothing.
4. Stage each file as it is finished: git add <file>.

Never resolve by blindly taking one whole side (-X ours/-X theirs) unless the file's two sides are genuinely one-or-the-other — that silently drops the other intent.

4. Run the project's automated checks

Discover the checks before running them (do not assume). Typical order: typecheck → tests → format.

cat package.json        # scripts: typecheck / lint / test / build / format
ls Makefile justfile pyproject.toml Cargo.toml go.mod 2>/dev/null

Run what exists (for this kit: npm run typecheck, npm test, npm run lint). Fix anything the merge broke — a resolution can be marker-free yet semantically wrong (e.g. a function both sides renamed differently). Re-run until green.

5. Obtain approval, then finish the merge/rebase

• Ask first: present the resolved files and check results. Do not run the following commands until the user explicitly approves completion.
• Merge: stage everything, then commit. The prepared message is usually correct; keep it conventional and free of AI references.

  git add -A
  git commit --no-edit        # or write a conventional message if none is prepared
  

• Rebase: continue, and loop — a rebase pauses once per conflicting commit.

  git add -A
  git rebase --continue       # repeat steps 1-4 for each subsequent pause
  

  Repeat until git status reports the rebase is complete (no further stops).

Confirm a clean tree (git status → "nothing to commit, working tree clean") before handing off.

Output Format

## Merge Conflict Resolution: {merge|rebase} of {source} into {target}

**Conflicted files:** {n}
**Resolution summary:**
- {file}: {kept both | chose {side} because {merge goal} — dropped {discarded intent}}

**Checks:** typecheck {pass/fail} · tests {pass/fail} · format {pass/fail}
**Finished:** {awaiting approval | commit sha | rebase complete}

Failure Handling

Handoff Protocol

On a clean tree with green checks → return to mk:ship (if mid-ship) or mk:verify to confirm the full build is green before continuing.

Gotchas

• ours/theirs invert between merge and rebase — during rebase, ours is the upstream you are replaying onto, not your own work. Confirm direction before picking a side.
• Marker-free ≠ resolved — code with no conflict markers can still be semantically broken (both sides edited the same logic differently). Step 4's checks are what prove it.
• git rebase --continue pauses repeatedly — one stop per conflicting commit. It is not done until git status says so; resolving the first pause is not the end.