commit-msg

#!/usr/bin/env bash
#
# Global commit-msg hook — calls Claude Code to review every commit.
# Install via: ~/ai-commit-hook/install.sh
# Bypass with: git commit --no-verify
#
set -euo pipefail

MODEL="__MODEL__"

COMMIT_MSG_FILE="$1"

# ── Gather context ──────────────────────────────────────────────────
REPO_ROOT="$(git rev-parse --show-toplevel 2>/dev/null)"
REPO_NAME="$(basename "$REPO_ROOT")"
BRANCH="$(git branch --show-current 2>/dev/null || echo "detached")"
COMMIT_MSG="$(git stripspace --strip-comments < "$COMMIT_MSG_FILE")"
FILE_LIST="$(git diff --cached --name-status)"
DIFF="$(git diff --cached)"

# Nothing staged? Let git handle the error.
if [ -z "$DIFF" ]; then
    exit 0
fi

# ── Guard against huge diffs ────────────────────────────────────────
MAX_LINES=20000
DIFF_LINES="$(echo "$DIFF" | wc -l | tr -d ' ')"
TRUNCATED=""
if [ "$DIFF_LINES" -gt "$MAX_LINES" ]; then
    DIFF="$(echo "$DIFF" | head -n "$MAX_LINES")"
    TRUNCATED="[WARNING: Diff truncated from $DIFF_LINES to $MAX_LINES lines]"
fi

# ── Build the prompt ────────────────────────────────────────────────
PROMPT="You are a senior code reviewer. Analyze this Git commit and provide a SHORT report (max 10 lines).

Repository: ${REPO_NAME}
Branch: ${BRANCH}

== Commit Message ==
${COMMIT_MSG}

== Files Changed ==
${FILE_LIST}

== Diff ==
${DIFF}
${TRUNCATED}

Review checklist:
- Does the commit message accurately describe the changes?
- Any obvious bugs, logic errors, or typos in the code?
- Any security concerns (secrets, injection, unsafe operations)?
- Any leftover debug code (console.log, print, TODO)?

Format:
SUMMARY: One-line overall assessment
ISSUES: Bulleted list of concerns (or \"None found\")
SUGGESTIONS: Bulleted list of optional improvements (or \"Looks good\")"

# ── Call Claude Code ────────────────────────────────────────────────
echo ""
echo "═══════════════════════════════════════════════════════════════"
echo "  Claude Code Review  ·  ${REPO_NAME} @ ${BRANCH}"
echo "═══════════════════════════════════════════════════════════════"
echo ""

REVIEW="$(claude -p "$PROMPT" --model "$MODEL" --output-format text --max-turns 1 2>&1)" || {
    echo "⚠  Claude review failed (exit $?). Proceeding with commit."
    echo "$REVIEW"
    # Don't block commits if Claude is unavailable
    exit 0
}

echo "$REVIEW"
echo ""
echo "═══════════════════════════════════════════════════════════════"

# ── Prompt user ─────────────────────────────────────────────────────
printf "\nProceed with commit? [Y/n] "
read -r REPLY </dev/tty || REPLY=""

case "$REPLY" in
    [nNaA]*)
        echo ""
        echo "Commit aborted. Your commit message was:"
        echo "───────────────────────────────────────────"
        echo "$COMMIT_MSG"
        echo "───────────────────────────────────────────"
        exit 1
        ;;
    *)
        echo "Continuing with commit."
        ;;
esac

# ── Chain to local repo hook if it exists ───────────────────────────
LOCAL_HOOK="${REPO_ROOT}/.git/hooks/commit-msg"
if [ -x "$LOCAL_HOOK" ]; then
    exec "$LOCAL_HOOK" "$@"
fi