Can I use this with my existing test runner?

Yes, it is designed to work seamlessly with popular runners including Vitest, Jest, Pytest, Cargo Test, and Go Test.

How do the phase boundaries work?

The skill restricts what can be edited during each phase: Red allows only test file edits, Domain allows only type and stub definitions, and Green allows only implementation bodies.

Which programming languages does this skill support?

It features built-in support for Rust, TypeScript/JavaScript, Python, Go, and Elixir, automatically detecting the test runner and project structure for each.

What makes this different from standard TDD?

Unlike traditional TDD, this skill adds a dedicated 'Domain' phase and enforces strict file boundaries, ensuring that architectural design and type safety are never skipped during the testing or implementation cycles.

Why does it enforce one assertion per test?

Single assertions ensure that when a test fails, the specific behavior that failed is immediately obvious, eliminating the need to debug multiple failure points within a single test case.

TDD Constraints Workflow

Name: TDD Constraints Workflow
Author: jwilger

byjwilger

•

安全与测试

Enforces a disciplined three-phase TDD cycle with strict file boundaries and integrated domain modeling reviews to prevent primitive obsession.

TDD Constraints is a specialized workflow skill designed to elevate the standard Red-Green-Refactor loop by introducing mandatory domain modeling checkpoints and strict file-access boundaries. By mechanically separating test writing, type definition, and implementation into isolated phases, it ensures that tests drive design while preventing common pitfalls like anemic models and leaky abstractions. This skill is ideal for developers building complex domain-driven systems who require high architectural integrity and clear separation of concerns from the very first line of code.

主要功能

01Integrated domain modeling reviews to eliminate primitive obsession and invalid states

027 GitHub stars

03Enforcement of the 'one assertion per test' principle for rapid failure diagnosis

04Automated environment detection for Rust, TypeScript, Python, Go, and Elixir

05Three-phase cycle (Red, Domain, Green) with mandatory modeling checkpoints

06Strict file ownership boundaries to prevent simultaneous testing and implementation

使用场景

01Building complex Domain-Driven Design (DDD) systems requiring robust type safety

02Onboarding development teams to a disciplined TDD workflow with automated guardrails

03Refactoring legacy codebases into domain-rich architectures using strict implementation cycles

What are Skills?·How to Install

Install with 🐟 Skill.Fish

npx skillfish add jwilger/claude-code-plugins tdd-constraints

For use in Claude.ai and ChatGPT

Download Skill