Git Hooks — Pre-Commit Lint and Format

#!/usr/bin/env bash
# .git/hooks/pre-commit (make executable: chmod +x)
set -euo pipefail

echo "🔍 Running pre-commit checks..."

# Get staged files only
STAGED_FILES=$(git diff --cached --name-only --diff-filter=ACMR)

# 1. Lint TypeScript/JavaScript files
TS_FILES=$(echo "$STAGED_FILES" | grep -E '\.(ts|tsx|js|jsx)$' || true)
if [[ -n "$TS_FILES" ]]; then
  echo "Linting TypeScript/JavaScript..."
  echo "$TS_FILES" | xargs npx eslint --fix
  echo "$TS_FILES" | xargs git add  # re-stage after fix
fi

# 2. Format with Prettier
FMT_FILES=$(echo "$STAGED_FILES" | grep -E '\.(ts|tsx|js|jsx|json|md|css)$' || true)
if [[ -n "$FMT_FILES" ]]; then
  echo "Formatting with Prettier..."
  echo "$FMT_FILES" | xargs npx prettier --write
  echo "$FMT_FILES" | xargs git add
fi

# 3. Check for secrets / sensitive data
if echo "$STAGED_FILES" | xargs grep -lE '(AKIA|sk-|password\s*=)' 2>/dev/null; then
  echo "❌ Potential secrets detected! Aborting commit."
  exit 1
fi

# 4. Run type check
echo "Type-checking..."
npx tsc --noEmit

echo "✅ All pre-commit checks passed!"