How can I test if my hook handles malformed JSON?

The skill includes a dedicated JSON validation pattern that passes empty or partial JSON objects to the hook to ensure it handles errors gracefully without crashing.

Do I need to use the UV package manager?

While the patterns are optimized for UV to handle self-executing scripts and dependencies, the core pytest logic can be adapted for any Python environment.

Why is the subprocess method recommended for testing hooks?

Using subprocess simulates the actual production environment where Claude Code executes your hook scripts, ensuring that stdin communication and stdout JSON parsing work as expected.

How do I run these tests?

Tests can be run as self-executing scripts (./test_hooks.py), via standard pytest commands, or with coverage tools for full verification.

What Claude Code hook types are supported?

This skill provides specific testing patterns and I/O formats for both Command hooks (interfacing with tools like Bash) and Prompt hooks (interfacing with user messages).

Claude Code Hook Testing Guide

Name: Claude Code Hook Testing Guide
Author: edmundmiller

byedmundmiller

•

セキュリティとテスト

Provides a standardized framework and testing patterns for validating Claude Code plugin hooks using pytest and UV.

概要

This skill equips developers with a robust testing methodology for Claude Code plugin hooks, focusing on Command and Prompt hook types. It offers ready-to-use patterns for subprocess-based testing, JSON validation, and edge-case handling, ensuring that custom automation scripts interact correctly with Claude via stdin/stdout. By leveraging the UV package manager and pytest, it simplifies the creation of self-executing test suites that maintain high reliability for custom Claude Code extensions and dotfile integrations.

主な機能

Multi-scenario parameterization for complex hook logic
JSON input/output validation and edge-case handling
40 GitHub stars
Pre-configured UV shebangs for self-executing test scripts
Subprocess-based testing patterns for Command and Prompt hooks
Minimalist testing philosophy for rapid plugin development

ユースケース

Regression testing for custom Claude Code plugins during infrastructure updates
Testing prompt hooks to ensure they provide appropriate context or restrictions to Claude
Validating that custom command hooks correctly block or allow specific CLI tools

概要

主な機能

Multi-scenario parameterization for complex hook logic
JSON input/output validation and edge-case handling
40 GitHub stars
Pre-configured UV shebangs for self-executing test scripts
Subprocess-based testing patterns for Command and Prompt hooks
Minimalist testing philosophy for rapid plugin development

ユースケース

Regression testing for custom Claude Code plugins during infrastructure updates
Testing prompt hooks to ensure they provide appropriate context or restrictions to Claude
Validating that custom command hooks correctly block or allow specific CLI tools