---

name: fp-refactor description: Comprehensive guide for refactoring imperative TypeScript code to fp-ts functional patterns risk: critical source: community date_added: "2026-09-04" version: 1.0.0 author: fp-ts-skills tags:

• fp-ts
• refactoring
• functional-programming
• typescript
• migration
• either
• option
• task
• reader

---

Refactoring Imperative Code to fp-ts

This skill provides comprehensive patterns and strategies for migrating existing imperative TypeScript code to fp-ts functional programming patterns.

Detailed Guide

Read the detailed guide before executing this skill. It retains the complete procedure and reference material. Treat its safety, prerequisites, and validation requirements as mandatory. For focused work, load the relevant sections; for end-to-end work, read the guide completely.

When to Use

• You are refactoring an existing imperative TypeScript codebase toward fp-ts patterns.
• The task involves converting try/catch, null checks, callbacks, DI, or loops into functional equivalents.
• You need migration guidance and tradeoffs, not just isolated fp-ts examples.

Limitations

• Use this skill only when the task clearly matches the scope described above.
• Do not treat the output as a substitute for environment-specific validation, testing, or expert review.
• Stop and ask for clarification if required inputs, permissions, safety boundaries, or success criteria are missing.