oh-conflict

name: oh-conflict description: Resolve merge conflicts on a PR by merging base into head

oh-conflict

Resolve merge conflicts on a pull request. Work in an isolated worktree, merge the base branch into the PR head, resolve conflicts with understanding of both sides' intent, verify, and push.

Invocation

/oh-conflict <pr-number>

• <pr-number> - the pull request number with merge conflicts

Prerequisites

• Repo context: Run from the repo root where the PR exists
• GitHub issue PR: The PR should be from an oh-task session (branch issue/<number>)

Flow

1. Read dive context (if available) for project background:

   cat .wm/dive_context.md 2>/dev/null || echo "No dive context"
   

2. Get PR branch info:

   # Save original directory for cleanup
   ORIGINAL_DIR=$(pwd)
   
   # Get head and base branch names
   PR_INFO=$(gh pr view <pr-number> --json headRefName,baseRefName)
   BRANCH=$(echo "$PR_INFO" | jq -r .headRefName)
   BASE=$(echo "$PR_INFO" | jq -r .baseRefName)
   

3. Create worktree and set up:

   git fetch origin
   git worktree add .worktrees/conflict-<pr-number> -B $BRANCH origin/$BRANCH
   cd .worktrees/conflict-<pr-number>
   sg init
   

4. Understand the PR's intent before merging:

   # Read the linked issue to understand what this PR is trying to do
   PARENT_ISSUE=${BRANCH#issue/}
   gh issue view $PARENT_ISSUE
   
   # See the PR's own changes (what this branch introduced)
   git log --oneline origin/$BASE..$BRANCH
   git diff origin/$BASE...$BRANCH --stat
   

5. Attempt the merge:

   git merge origin/$BASE --no-edit
   

   This will fail with conflict markers in affected files.

6. Resolve conflicts file by file:

   • For each conflicted file, read both sides:

     git diff --name-only --diff-filter=U  # List conflicted files
     

   • Understand the intent of BOTH sides:
     • Ours (HEAD/PR branch): What did this PR change and why?
     • Theirs (base branch): What changed on base since this PR branched?
   • Resolve by preserving the intent of both sides
   • If the PR's changes are superseded by base, accept theirs
   • If both sides changed the same logic, merge the intents
   • Stage each resolved file: git add <file>

7. After all conflicts resolved, verify:

   # Ensure no remaining conflict markers
   grep -rn '<<<<<<< ' --include='*.ts' --include='*.js' --include='*.rs' . || echo "No conflict markers"
   
   # Run project checks
   # For TypeScript projects:
   pnpm typecheck 2>&1 || true
   pnpm test 2>&1 || true
   
   # For Rust projects:
   cargo check 2>&1 || true
   cargo test 2>&1 || true
   

   Adapt commands to the project's build system.

8. If verification fails (e.g., type errors from merged code):

   • Fix the issues introduced by the merge
   • Stage fixes
   • Run sg review on staged changes
   • Handle review findings:
     • P1-P3 trivial: fix inline
     • P1-P3 non-trivial: create GitHub issue as descendant
     • P4: discard

9. Complete the merge commit:

   git commit --no-edit  # Uses the auto-generated merge commit message
   

10. Push:

    git push
    

11. Cleanup worktree:

    cd $ORIGINAL_DIR
    git worktree remove .worktrees/conflict-<pr-number>
    

12. Exit and report:

    • List conflicted files and how each was resolved
    • Note any verification issues encountered
    • Provide PR URL

Conflict Resolution Strategy

Simple cases (auto-resolve)

• Import additions on both sides: Keep both imports
• Adjacent but non-overlapping changes: Accept both
• Lockfile conflicts (package-lock.json, pnpm-lock.yaml, Cargo.lock): Accept base version, then regenerate:

  # Accept theirs for lockfiles
  git checkout --theirs pnpm-lock.yaml
  pnpm install
  git add pnpm-lock.yaml
  

Complex cases (manual resolution)

• Same function changed on both sides: Read the issue to understand PR intent, merge logically
• File moved on one side, edited on other: Apply the edit to the moved file
• Schema/type changes on both sides: Merge the types, verify all consumers

When to escalate

• Architectural conflicts: Both sides restructured the same module differently
• Semantic conflicts: No textual conflict but merged code is logically wrong
• Report as blocked with clear description of what needs human decision

Descendant Issues

If sg review finds non-trivial issues during resolution:

PARENT_ISSUE=${BRANCH#issue/}
NEW_ISSUE=$(gh issue create \
  --title "Fix: <brief description>" \
  --body "Spawned from #${PARENT_ISSUE} during conflict resolution on PR #<pr-number>.

## Context
<what was found>

## Acceptance
- [ ] Fix applied
- [ ] Tests pass" \
  --assignee @me | grep -oE '[0-9]+$')

Complete ALL descendant issues before the final push.

Exit Conditions

• Success: All conflicts resolved, verification passes, changes pushed
• Blocked: Conflict requires human architectural decision
• Error: Cannot resolve without breaking functionality

Completion Signaling (MANDATORY)

CRITICAL: You MUST signal completion when done. Call the signal_completion tool as your FINAL action. Signal based on outcome:

Fallback: If the signal_completion tool is not available, output your completion status as your final message in the format: COMPLETION: status=<status> pr=<url> or COMPLETION: status=<status> error=<reason>.