swain-sync

name	swain-sync
description	Fetch upstream, merge (worktree) or rebase (tracked branch), stage all changes, enforce gitignore hygiene, run ADR compliance checking on modified artifacts, rebuild stale artifact indexes, generate a descriptive commit message from the diff, commit, and push to the current branch's upstream. Handles merge conflicts by preferring local changes for config/project files and upstream for scaffolding.
user-invocable	true
allowed-tools	Bash, Read, Edit, Write, Glob
metadata	{"short-description":"Fetch, stage, commit, and push","version":"1.5.0","author":"cristos","license":"MIT","source":"swain"}

Run through the following steps in order without pausing for confirmation unless a decision point is explicitly marked as requiring one.

Delegate this to a sub-agent so the main conversation thread stays clean. Include the full text of these instructions in the agent prompt, since sub-agents cannot read skill files directly.

Step 1 — Detect worktree context and fetch/rebase upstream

First, detect whether you are running in a git linked worktree:

GIT_COMMON=$(git rev-parse --git-common-dir)
GIT_DIR=$(git rev-parse --git-dir)
IN_WORKTREE=$( [ "$GIT_COMMON" != "$GIT_DIR" ] && echo "yes" || echo "no" )
REPO_ROOT=$(git rev-parse --show-toplevel)
TRUNK=$(bash "$REPO_ROOT/scripts/swain-trunk.sh")

IN_WORKTREE=yes means the current directory is inside a linked worktree (e.g., .claude/worktrees/agent-abc123). Use this flag in Steps 3, 6, and the session bookmark step.

Next, check whether the current branch has an upstream tracking branch:

git --no-pager rev-parse --abbrev-ref --symbolic-full-name @{u} 2>/dev/null

If there is an upstream, fetch and rebase to incorporate upstream changes BEFORE staging or committing:

git fetch origin

If there are local changes (dirty working tree), stash them first:

BRANCH=$(git rev-parse --abbrev-ref HEAD)
git stash push -m "swain-sync: auto-stash [$BRANCH]"
git --no-pager rebase origin/$BRANCH
git stash pop

If the rebase has conflicts after stash pop, abort and report:

git rebase --abort  # if rebase itself conflicts
git stash pop       # recover stashed changes

Show the user the conflicting files and stop. Do not force-push or drop changes.

If there is no upstream (@{u} returns an error) and IN_WORKTREE=yes, the worktree branch has no remote tracking counterpart. Merge the trunk branch to combine the agent's changes with whatever landed since the branch was created:

git fetch origin
git merge "origin/$TRUNK" --no-edit

If the merge has conflicts, report them and stop. Do not attempt to auto-resolve.

If origin cannot be fetched, skip fetch/rebase and proceed to Step 2.

If there is no upstream and IN_WORKTREE=no (main worktree, new branch), skip this step entirely.

Step 2 — Survey the working tree

git --no-pager status
git --no-pager diff          # unstaged changes
git --no-pager diff --cached # already-staged changes

If the working tree is completely clean and there is nothing to push, report that and stop.

Step 3 — Stage changes

Identify files that look like secrets (.env, *.pem, *_rsa, credentials.*, secrets.*). If any are present, warn the user and exclude them from staging.

If there are 10 or fewer changed files (excluding secrets), stage them individually:

git add file1 file2 ...

If there are more than 10 changed files, stage everything and then unstage secrets:

git add -A
git reset HEAD -- <secret-file-1> <secret-file-2> ...

Step 3.5 — Gitignore check

Before committing, verify .gitignore hygiene. This step is blocking — if relevant patterns are missing, stop and require the user to fix .gitignore before proceeding.

1. Check existence

If no .gitignore file exists in the repo root:

STOP: No .gitignore file found. Create one before committing — without it, secrets, build artifacts, and OS files can enter git history. Minimal starting point: curl -sL https://www.toptal.com/developers/gitignore/api/macos,linux,node,python > .gitignore

Stop execution. Do not commit.

2. Detect relevant patterns

Check which patterns are relevant to this repo, based on what actually exists on disk:

Pattern	Relevant if
.env	.env.example exists, OR any untracked/tracked .env or .env.* file is present (excluding .env.example), OR dotenv appears in package.json or requirements.txt
node_modules/	package.json exists in the repo root or any subdirectory
__pycache__/	any *.py file exists in the repo
*.pyc	same as __pycache__/
.DS_Store	repo is on macOS (uname returns Darwin)

For each relevant pattern, check if .gitignore contains it (exact match or substring). Collect missing ones.

3. Decide whether to block

• If no relevant patterns are missing: this step is silent. Continue to Step 3.7.

• If any relevant patterns are missing: stop and report:

  STOP: .gitignore is missing patterns relevant to this repo:

  • .env — .env.example found; without this, a local .env file could be committed
  • node_modules/ — package.json found

  Add the missing patterns before committing: echo ".env" >> .gitignore echo "node_modules/" >> .gitignore

  To permanently suppress a specific pattern check (intentional omission), add a comment to .gitignore:

  swain-sync: allow .env

  Stop execution. Do not commit until the user resolves this.

4. Skip logic

If .gitignore contains # swain-sync: allow <pattern> for a given pattern, treat that pattern as intentionally omitted and do not flag it.

Step 3.7 — ADR compliance check

If modified files include any swain artifacts (docs/spec/, docs/epic/, docs/vision/, docs/research/, docs/journey/, docs/persona/, docs/runbook/, docs/design/, docs/train/), run an ADR compliance check against each modified artifact:

bash "$(find "$(git rev-parse --show-toplevel 2>/dev/null || pwd)" -path '*/swain-design/scripts/adr-check.sh' -print -quit 2>/dev/null)" <artifact-path>

For each artifact with findings (exit code 1 = advisory RELEVANT findings, exit code 2 = actionable DEAD_REF or STALE findings), collect the output and present a single consolidated warning after all checks complete:

ADR compliance: N artifact(s) have findings that may need attention.

This step is advisory — it warns but never blocks the commit. Continue to Step 4 regardless.

If the adr-check.sh script is not found or fails with exit code 3, skip silently — the check is only available in repos with swain-design installed.

Step 3.8 — Design drift check

Run design-check.sh with no arguments (scan all active DESIGNs) to detect design-to-code drift:

bash "$(find "$(git rev-parse --show-toplevel 2>/dev/null || pwd)" -path '*/swain-design/scripts/design-check.sh' -print -quit 2>/dev/null)" 2>/dev/null

For each DESIGN with findings (STALE or BROKEN sourcecode-refs), collect the output and present a single consolidated warning after the check completes:

Design drift: N DESIGN(s) have stale or broken sourcecode-refs.

This step is advisory — it warns but never blocks the commit. Continue to Step 4 regardless.

If the design-check.sh script is not found or fails with exit code 2, skip silently — the check is only available in repos with swain-design installed.

Step 3.9 — Artifact number collision check

Run detect-duplicate-numbers.sh to find duplicate artifact numbers introduced by merges or concurrent worktree work:

bash "$(find "$(git rev-parse --show-toplevel 2>/dev/null || pwd)" -path '*/swain-design/scripts/detect-duplicate-numbers.sh' -print -quit 2>/dev/null)" 2>/dev/null

If collisions are found (exit code 1), this step is blocking — do not commit until resolved:

Artifact number collision detected:

Auto-fix available: run fix-collisions.sh to renumber the newer artifact(s). Or run fix-collisions.sh --dry-run to preview changes first.

Offer to run fix-collisions.sh automatically. If the operator accepts, run it, stage the changes, and continue to Step 4. If the operator declines, stop execution — do not commit with duplicate numbers.

If the script is not found, skip silently — the check is only available in repos with swain-design installed.

Step 4 — Generate a commit message

Read the staged diff (git --no-pager diff --cached) and write a commit message that:

• Opens with a conventional-commit prefix matching the dominant change type:
  • feat — new feature or capability
  • fix — bug fix
  • docs — documentation only
  • chore — tooling, deps, config with no behavior change
  • refactor — restructuring without behavior change
  • test — test additions or fixes
• Includes a concise imperative-mood subject line (≤ 72 chars).
• Adds a short body (2–5 lines) summarising why, not just what, when the diff is non-trivial.
• Appends a Co-Authored-By trailer identifying the model that generated the commit. Use the model name from your system prompt (e.g., Claude Opus 4.6, Gemini 2.5 Pro). If you can't determine the model name, use AI Assistant as a fallback.

Example shape:

feat(terraform): add Cloudflare DNS module for hub provisioning

Operators can now point DNS at Cloudflare without migrating their zone.
Module is activated by dns_provider=cloudflare and requires only
CLOUDFLARE_API_TOKEN — no other provider credentials are validated.

Co-Authored-By: Claude Opus 4.6 <[e-mail]>

Step 4.5 — Pre-commit hook check

Check if pre-commit hooks are configured:

test -f .pre-commit-config.yaml && command -v pre-commit >/dev/null 2>&1 && echo "hooks-configured" || echo "no-hooks"

If no-hooks, emit a one-time warning (do not repeat if the same session already warned):

WARN: No pre-commit hooks configured. Run /swain-init to set up security scanning.

Continue to Step 5 regardless — hooks are recommended but not required.

Step 5 — Commit

git --no-pager commit -m "$(cat <<'EOF'
<generated message here>
EOF
)"

Use a heredoc so multi-line messages survive the shell without escaping issues.

IMPORTANT: Never use --no-verify. If pre-commit hooks are installed, they MUST run. There is no bypass.

If the commit fails because a pre-commit hook rejected it:

1. Parse the output to identify which hook(s) failed and what was found
2. Present findings clearly:

   Pre-commit hook failed: gitleaks: 2 findings (describe what was flagged)

   Fix the findings and run /swain-sync again. Suppress false positives: add to .gitleaksignore

3. Stop execution — do not push. Do not retry automatically.

Step 6 — Push

If IN_WORKTREE=yes: push the worktree's commits directly to trunk (the development branch):

MAX_RETRIES=3
ATTEMPT=0
while [ $ATTEMPT -lt $MAX_RETRIES ]; do
  git push origin "HEAD:$TRUNK" && break
  ATTEMPT=$((ATTEMPT + 1))
  if [ $ATTEMPT -lt $MAX_RETRIES ]; then
    echo "Push rejected (attempt $ATTEMPT/$MAX_RETRIES). Fetching and re-merging..."
    git fetch origin
    git merge "origin/$TRUNK" --no-edit || {
      echo "Merge conflict during retry. Reporting to operator."
      git merge --abort
      break
    }
    # Run tests on the merged result before retrying push
    # (project-specific test command — detect from project structure)
  fi
done

if [ $ATTEMPT -ge $MAX_RETRIES ]; then
  echo "Push failed after $MAX_RETRIES attempts. Reporting to operator."
fi

If the push is rejected due to branch protection rules or required reviews (check the rejection message), fall back to opening a PR instead:

BRANCH=$(git rev-parse --abbrev-ref HEAD)
SUBJECT=$(git log -1 --pretty=format:'%s')
BODY=$(git log -1 --pretty=format:'%b')
gh pr create --base "$TRUNK" --head "$BRANCH" --title "$SUBJECT" --body "$BODY"

Report the PR URL. Do not retry the push. Proceed to worktree pruning below.

After a successful push or PR creation, clean up the worktree — but only if swain-sync created it. Worktrees entered via EnterWorktree (branch name matches worktree-*) must be left for ExitWorktree to clean up, since ExitWorktree properly restores the session's CWD before removal. Removing them here would leave the parent session's CWD pointing at a deleted directory, causing ENOENT on all subsequent hook spawns (SPEC-127).

WORKTREE_PATH=$(pwd)
BRANCH=$(git rev-parse --abbrev-ref HEAD)
MAIN_REPO=$(git rev-parse --git-common-dir | sed 's|/.git$||')

case "$BRANCH" in worktree-*)
  # SPEC-127: Worktree entered via EnterWorktree — do NOT remove.
  # ExitWorktree handles cleanup and CWD restoration.
  echo "Worktree branch '$BRANCH' entered via EnterWorktree — skipping removal (ExitWorktree will clean up)."
  ;;
*)
  # SPEC-100: Restore CWD *before* removal — otherwise the session is stuck
  # in a deleted directory and all subsequent commands (hooks, git, etc.) fail.
  cd "$MAIN_REPO" || cd "$HOME"
  git -C "$MAIN_REPO" worktree remove --force "$WORKTREE_PATH" 2>/dev/null || true
  git -C "$MAIN_REPO" worktree prune 2>/dev/null || true
  ;;
esac

If IN_WORKTREE=no (main worktree, normal case):

git push          # or: git push -u origin HEAD (if no upstream)

If push fails due to divergent history (shouldn't happen after Step 1 rebase, but as a safety net):

git --no-pager pull --rebase
git push

Step 7 — Verify

Run git --no-pager status and git --no-pager log --oneline -3 to verify the push landed and show the user the final state. Do not prompt for confirmation — just report the result.

Index rebuild (SPEC-047)

Before committing (after staging, before Step 5), check whether any artifact index files (list-*.md) are stale. If the rebuild script exists, run it for each artifact type that had changes staged:

REBUILD_SCRIPT="$(find "$REPO_ROOT" -path '*/swain-design/scripts/rebuild-index.sh' -print -quit 2>/dev/null)"
if [[ -x "$REBUILD_SCRIPT" ]]; then
    # Detect which types had staged changes
    for type in spec epic spike adr persona runbook design vision journey train; do
        if git diff --cached --name-only | grep -q "^docs/$type/"; then
            bash "$REBUILD_SCRIPT" "$type"
            git add "docs/$type/list-${type}.md" 2>/dev/null || true
        fi
    done
fi

This ensures the index is current when the session's commits land.

Session bookmark

After a successful push, update the bookmark. Use $REPO_ROOT (set in Step 1) as the search root so this works from both main and linked worktrees:

bash "$(find "$REPO_ROOT" -path '*/swain-session/scripts/swain-bookmark.sh' -print -quit 2>/dev/null)" "Pushed {n} commits to {branch}"