Pre-Commit Lint

Pre-ToolBeginnerHook Type: pre-tool-use

Pre-Commit Lint hooks into the pre-tool-use event for Bash commands that contain 'git commit'. Before the commit executes, it runs ESLint on staged files and checks Prettier formatting. If any lint errors or formatting issues are found, it blocks the commit and reports the problems so Claude can fix them first. This ensures every commit meets your project's code quality standards without manual intervention.

linteslintprettiercode-qualitycommit

Hook Code

#!/bin/bash
# Pre-Commit Lint Hook
# Runs ESLint and Prettier on staged files before git commit

# Only intercept git commit commands
if [[ "$TOOL_NAME" != "Bash" ]] || ! echo "$TOOL_INPUT" | grep -q "git commit"; then
  exit 0
fi

STAGED_FILES=$(git diff --cached --name-only --diff-filter=ACMR | grep -E '\.(ts|tsx|js|jsx)$')

if [ -z "$STAGED_FILES" ]; then
  exit 0
fi

echo "Running ESLint on staged files..."
npx eslint $STAGED_FILES --quiet
LINT_EXIT=$?

echo "Checking Prettier formatting..."
npx prettier --check $STAGED_FILES 2>/dev/null
FORMAT_EXIT=$?

if [ $LINT_EXIT -ne 0 ] || [ $FORMAT_EXIT -ne 0 ]; then
  echo "ERROR: Lint or format issues found. Fix before committing."
  exit 1
fi

echo "All checks passed."
exit 0

Add this hook to your Claude Code settings or .claude/settings.json to activate.

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Pre-Commit Lint

About Pre-Commit Lint

Claude Code hooks let you run custom shell commands automatically in response to specific events during Claude's operation. Pre-Commit Lint is a Pre-Tool hook at the Beginner level that automates tasks at key moments in your development workflow, reducing manual steps and enforcing consistency across your team.

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