Merge conflict resolver

Merge Conflict Resolver

Resolve git merge conflicts by analyzing both sides, recommending a resolution, and letting the user make the final call.

When this skill activates

The user has one or more files with unresolved git conflicts — whether from git merge, git rebase, git cherry-pick, or git stash pop. They want help understanding what happened and choosing the right resolution.

Step 1: Assess the situation

Run these commands to build context:

git status

This tells you which files are in conflict (look for "both modified", "both added", "deleted by us/them", etc.) and what operation is in progress (merge, rebase, cherry-pick).

If it's a merge:

git log --oneline --graph -10

If it's a rebase or cherry-pick, also check:

git rebase --show-current-patch 2>/dev/null || true

Summarize the situation to the user briefly: what operation caused the conflicts, how many files are affected, and which branches/commits are involved.

Step 2: Analyze each conflicted file

For each conflicted file, read it and locate the conflict markers:

• <<<<<<< HEAD (or <<<<<<< ours) — the current branch's version
• ======= — separator
• >>>>>>> branch-name (or >>>>>>> theirs) — the incoming branch's version

For each conflict hunk, understand what both sides are doing. Use git history for additional context when the intent isn't obvious:

git log --oneline -5 -- <file>
git log --oneline -5 MERGE_HEAD -- <file> 2>/dev/null || true

This helps you understand why each side made its changes, which is critical for a good recommendation.

Step 3: Present conflicts and recommend

For each conflict hunk, present the user with:

1. File and location — which file, which lines
2. "Ours" (current branch) — what this side does and likely why
3. "Theirs" (incoming branch) — what this side does and likely why
4. Recommendation — your suggested resolution and reasoning

Your recommendation should be one of:

• Keep ours — when the current branch's version is correct or more complete
• Keep theirs — when the incoming branch's version is correct or more complete
• Combine both — when both sides made independent, non-overlapping changes that should coexist (show the proposed combined version)
• Rewrite — when neither side is fully correct and a new version is needed (show the proposed rewrite)

Always show the exact code you're proposing as the resolution so the user can evaluate it.

Present conflicts one file at a time. If there are many files, group trivial conflicts (e.g., import ordering, whitespace) separately from substantive ones.

Step 4: Apply the resolution

Only after the user approves (or modifies) your recommendation for each conflict:

1. Edit the file to replace the conflict markers with the agreed-upon resolution
2. Verify no conflict markers remain in the file:

   grep -n "^<<<<<<< \|^=======$\|^>>>>>>> " <file>
   

3. Stage the resolved file:

   git add <file>
   

Repeat for each conflicted file.

Step 5: Wrap up

After all files are resolved and staged, tell the user what to do next based on the operation:

• Merge: "All conflicts resolved and staged. You can complete the merge with git commit (git will use the default merge commit message) or I can do it for you."
• Rebase: "All conflicts in this step are resolved. Run git rebase --continue to proceed, or I can do it for you." (Note: there may be more conflicts in subsequent rebase steps.)
• Cherry-pick: "All conflicts resolved. Run git cherry-pick --continue to finish, or I can do it for you."

Do not automatically commit or continue — let the user decide.

Edge cases

• Binary files: Flag these to the user — they can't be merged textually. Ask which version to keep, or if they need to manually re-create the file.
• Deleted vs modified: When one side deleted a file and the other modified it, explain the situation clearly and ask whether to keep the file (with modifications) or delete it.
• Massive conflicts: If there are more than 10 conflicted files, offer to triage — resolve the simple ones first, then focus on the complex ones.
• Conflict markers in strings/comments: Be careful not to confuse actual conflict markers with strings that happen to contain <<<<<<<. Real conflict markers start at column 0 and follow the exact pattern.