name: code-quality-hook
description: PostToolUse hook that checks code quality after Edit/Write operations. Reports violations for function size, nesting depth, file size, and commented-out code blocks as non-blocking feedback.

Code Quality Hook

A lightweight PostToolUse hook that checks files after Claude edits them. Reports quality violations as non-blocking feedback (exit code 2) so Claude can self-correct.

What It Checks

What It Skips

• Test/spec files (test, spec, _test.go, _spec.rb)
• Vendored code (node_modules, vendor, dist/, build/)
• Minified files (.min.js, .min.css)
• Generated files (checked via first-line markers)

Installation

Add to your settings.json (project or user level):

{
  "hooks": {
    "PostToolUse": [
      {
        "matcher": "Edit|Write",
        "hooks": [
          {
            "type": "command",
            "command": "python3 ~/.claude/skills/code-quality-hook/scripts/code_quality_check.py",
            "timeout": 15
          }
        ]
      }
    ]
  }
}

Behavior

• Exit 0: No violations found (or file skipped)
• Exit 2: Violations found — printed to stderr as non-blocking feedback to Claude
• Exit 1: Script error (does not block Claude)

Violations appear as feedback in Claude's context, prompting it to reconsider the code it just wrote. This is advisory, not blocking.

Manual Testing

echo '{"tool_name":"Edit","tool_input":{"file_path":"src/app.ts"}}' | python3 ~/.claude/skills/code-quality-hook/scripts/code_quality_check.py
echo $?