Introduces commands for test-driven development, common anti-patterns and skills for testing using subagents.

Installation

npx claude-plugins install @NeoLabHQ/context-engineering-kit/tdd

Contents

Folders: commands, skills

Files: README.md

Documentation

A disciplined approach to software development that ensures every line of production code is validated by tests written first. Introduces TDD methodology, anti-pattern detection, and orchestrated test coverage using specialized agents.

Focused on:

• Test-first development - Write tests before implementation, ensuring every feature is verified
• Red-Green-Refactor cycle - Systematic approach that builds confidence through failing tests
• Anti-pattern detection - Identifies common testing mistakes like mock abuse and test-only methods
• Agent-orchestrated coverage - Parallel test writing using specialized subagents for complex changes

Plugin Target

• Prevent regressions - Every change is backed by tests that catch future breaks
• Improve design quality - Hard-to-test code reveals design problems early
• Build confidence - Watching tests fail then pass proves they actually test something
• Accelerate development - TDD is faster than debugging untested code in production

Overview

The TDD plugin implements Kent Beck’s Test-Driven Development methodology, proven over two decades to produce higher-quality, more maintainable software. The core principle is simple but transformative: write the test first, watch it fail, then write minimal code to pass.

The plugin is based on foundational works including Kent Beck’s Test-Driven Development: By Example and the extensive research on TDD effectiveness.

Quick Start

# Install the plugin
/plugin install tdd@NeoLabHQ/context-engineering-kit

> claude "Use TDD skill to implement email validation for user registration"

# Manually make some changes that cause test failures

# Fix failing tests
> /tdd:fix-tests

After Implementation

If you implemented a new feature but have not written tests, you can use the write-tests command to cover it.

> claude "implement email validation for user registration"

# Write tests after you made changes
> /tdd:write-tests

Usage Examples

Commands Overview

/tdd:write-tests - Cover Local Changes with Tests

Systematically add test coverage for all local code changes using specialized review and development agents.

• Purpose - Ensure comprehensive test coverage for new or modified code
• Output - New test files covering all critical business logic

/tdd:write-tests ["focus area or modules"]

Arguments

Optional focus area specification. Defaults to all uncommitted changes. If everything is committed, covers the latest commit.

How It Works

1. Preparation Phase

   • Discovers test infrastructure (test commands, coverage tools)
   • Runs full test suite to establish baseline
   • Reads project conventions and patterns

2. Analysis Phase (parallel)

   • Verifies single test execution capability
   • Analyzes local changes via git status or latest commit
   • Filters non-code files and identifies logic changes
   • Assesses complexity to determine workflow path

3. Test Writing Phase

   • Simple changes (single file, straightforward logic): Writes tests directly
   • Complex changes (multiple files or complex logic): Orchestrates specialized agents
     • Coverage reviewer agents analyze each file for test needs
     • Developer agents write comprehensive tests in parallel
     • Verification agents confirm coverage completeness

4. Verification Phase

   • Runs full test suite
   • Generates coverage report if available
   • Iterates on gaps until all critical logic is covered

Complexity Decision:

• 1 simple file: Write tests directly
• 2+ files or complex logic: Orchestrate parallel agents

Usage Examples

# Cover all uncommitted changes
> /tdd:write-tests

# Focus on specific module
> /tdd:write-tests Focus on payment processing edge cases

# Cover authentication changes
> /tdd:write-tests authentication module

# Focus on error handling
> /tdd:write-tests Focus on error paths and validations

Best practices

• Run before committing - Ensure all changes have test coverage before commit
• Be specific - Provide focus areas for more targeted test generation
• Review generated tests - Verify tests actually test behavior, not implementation
• Iterate on gaps - Re-run if coverage reviewer identifies missing cases
• Prioritize critical logic - Not every line needs 100% coverage, focus on business logic

/tdd:fix-tests - Fix Failing Tests

Systematically fix all failing tests after business logic changes or refactoring using orchestrated agents.

• Purpose - Update tests to match current business logic after changes
• Output - Fixed tests that pass while preserving test intent

/tdd:fix-tests ["focus area or modules"]

Arguments

Optional specification of which tests or modules to focus on. Defaults to all failing tests.

How It Works

1. Discovery Phase
   • Reads test infrastructure configuration
   • Runs full

…(truncated)

Included Skills

This plugin includes 1 skill definition:

test-driven-development

Use when implementing any feature or bugfix, before writing implementation code - write the test first, watch it fail, write minimal code to pass; ensures tests actually verify behavior by requiring failure first

NO PRODUCTION CODE WITHOUT A FAILING TEST FIRST

digraph tdd_cycle {
    rankdir=LR;
    red [label="RED\nWrite failing test", shape=box, style=filled, fillcolor="#ffcccc"];
    verify_red [label="Verify fails\ncorrectly", shape=diamond];
    green [label="GREEN\nMinimal code", shape=box, style=filled, fillcolor="#ccffcc"];
    verify_green [label="Verify passes\nAll green", shape=diamond];
    refactor [label="REFACTOR\nClean up", shape=box, style=filled, fillcolor="#ccccff"];
    next [label="Next", shape=ellipse];

    red -> verify_red;
    verify_red -> green [label="yes"];
    verify_red -> red [label="wrong\nfailure"];
    green -> verify_green;
    verify_g

...(truncated)

</details>

## Source

[View on GitHub](https://github.com/NeoLabHQ/context-engineering-kit)