typescript-refactorlisted

# TypeScript Refactor Best Practices 43 rules across 8 categories for TypeScript refactoring and modernization, prioritized by impact to guide automated refactoring, code review, and code generation. ## When to Apply - Refactoring TypeScript code for type safety and maintainability - Designing type architectures (discriminated unions, branded types, generics) - Narrowing types to eliminate unsafe `as` casts - Adopting modern TypeScript 4.x-5.x features (`satisfies`, `using`, const type parameters) - Optimizing compiler performance in large codebases - Implementing type-safe error handling patterns - Reviewing code for TypeScript quirks and pitfalls ## Rule Categories by Priority | Priority | Category | Impact | Prefix | |----------|----------|--------|--------| | 1 | Type Architecture | CRITICAL | `arch-` | | 2 | Type Narrowing & Guards | CRITICAL | `narrow-` | | 3 | Modern TypeScript | HIGH | `modern-` | | 4 | Generic Patterns | HIGH | `generic-` | | 5 | Compiler Performance | MEDIUM-HIGH | `compile-` | | 6 | Error Safety | MEDIUM | `error-` | | 7 | Runtime Patterns | MEDIUM | `perf-` | | 8 | Quirks & Pitfalls | LOW-MEDIUM | `quirk-` | ## Quick Reference ### 1. Type Architecture (CRITICAL) - [`arch-discriminated-unions`](references/arch-discriminated-unions.md) — Use discriminated unions over string enums for exhaustive pattern matching - [`arch-branded-types`](references/arch-branded-types.md) — Use branded types for domain identifiers to prevent value mix-ups - [`a