Why are 'Branded Types' included?

Branded types prevent the accidental mixing of similar types, such as a UserId and a PostId, which are both strings but represent different domain entities.

How does this skill handle TypeScript errors?

Instead of using traditional 'throw' statements which can cause runtime crashes, this skill implements the Result type pattern (Success/Error) to ensure all error paths are handled at compile time.

Does this skill work with existing projects?

Yes, these patterns can be incrementally applied to any TypeScript project to improve code quality, safety, and maintainability without requiring a full rewrite.

Does this require specific libraries?

While many patterns are pure TypeScript, it specifically references 'ts-pattern' for advanced matching and encourages the use of functional programming principles.

What is the benefit of using ts-pattern with Claude?

ts-pattern allows Claude to perform exhaustive matching, meaning the AI will ensure that every possible case in a union type is explicitly handled, preventing logic gaps.

TypeScript Safety Patterns

Name: TypeScript Safety Patterns
Author: Higashi-Kota

byHigashi-Kota

0•

API Development

Implements robust, exception-free logic using Result types, discriminated unions, and exhaustive pattern matching.

This skill provides a comprehensive framework for writing high-integrity TypeScript code by replacing unsafe practices like 'any' and 'throw' with functional programming patterns. It equips Claude with the ability to implement Result and Option types, use branded types for domain safety, and leverage the ts-pattern library for exhaustive matching, ensuring that core business logic is immutable and type-safe at compile time. This is ideal for developers building complex systems where reliability and strict type enforcement are critical to reducing runtime errors.

Key Features

010 GitHub stars

02Enforces exhaustive pattern matching via ts-pattern to catch unhandled cases

03Replaces try-catch blocks with explicit Result type error handling

04Implements Branded Types to prevent confusion between identical primitive types

05Eliminates unsafe type assertions ('as') through discriminated unions

06Provides patterns for immutable data structures and readonly collections

Use Cases

01Designing complex state machines and domain models with zero runtime crashes

02Building mission-critical business logic that requires absolute type safety

03Refactoring legacy codebases to remove 'any' and unsafe type guards

What are Skills?·How to Install

Install with 🐟 Skill.Fish

npx skillfish add higashi-kota/llm-mermaid-chat type-patterns

For use in Claude.ai and ChatGPT

Download Skill