What tools does this skill require?

This skill is optimized for projects using Vitest as the test runner and the inferred-types library for robust, readable type assertions.

Does this support TDD workflows?

Yes, it provides a specific decision framework to help you determine which tests to write first, allowing for a type-first development approach.

Why should I test types and runtime logic in the same block?

Keeping them together ensures that any change in runtime behavior is immediately reflected in the type system, preventing type tests from drifting or becoming stale.

How does this differ from standard Vitest testing?

While Vitest handles runtime behavior, this skill adds a specialized layer for testing TypeScript's type system at design-time, ensuring generics and utility types resolve as expected.

Is this skill only useful for library authors?

No, it is highly beneficial for any TypeScript project with complex business logic, generic functions, or strict type-safety requirements where type accuracy is critical.

TypeScript Testing Suite

Name: TypeScript Testing Suite
Author: yankeeinlondon

byyankeeinlondon

•

Seguridad y Pruebas

Masters professional TypeScript testing workflows by integrating runtime behavior verification with deep type-level correctness assertions.

This skill provides comprehensive expertise for building robust TypeScript applications through a dual-testing approach. It guides developers in implementing runtime tests using Vitest while simultaneously validating complex type logic using specialized type-testing utilities. By enforcing a standardized 'type cases' pattern, it ensures that type utilities, generic constraints, and inferred return types are as well-tested as the execution logic, preventing regressions in both the code's behavior and the overall developer experience.

Características Principales

01Integrated runtime and type-testing workflows using Vitest and inferred-types assertions

022 GitHub stars

03Guidance on incorporating Test-Driven Development (TDD) for type-safe software architecture

04Automated validation of complex TypeScript generics, conditional types, and utility functions

05Decision framework for determining when to apply runtime vs. type-level tests

06Standardized 'type cases' pattern to prevent common type-testing anti-patterns

Casos de Uso

01Validating type-narrowing behavior for functions handling discriminated unions

02Verifying that complex TypeScript utility libraries return exact expected literal types

03Implementing TDD to ensure both business logic and type inference are correct during development

What are Skills?·How to Install

Install with 🐟 Skill.Fish

npx skillfish add yankeeinlondon/typed-tester testing

For use in Claude.ai and ChatGPT

Download Skill