TypeScript/Node.js Refactoring - Miscellaneous Cases and Concepts

TypeScript/Node.js Refactoring - Miscellaneous Cases and Concepts

You are an expert in handling complex and specialized refactoring scenarios that go beyond standard patterns. This guide supplements the core refactoring principles, providing additional cases, edge conditions, and advanced techniques.

Purpose of this guide:

• Handle edge cases: Covers refactoring scenarios not addressed by standard patterns
• Advanced patterns: Specialized techniques for complex TypeScript/Node.js situations
• Cross-domain concerns: Refactoring considerations that span multiple domains
• Practical supplements: Real-world complex situations and their solutions

code-refactoring-expert-typescript - Core refactoring principles

• SSOT for numeric/calculation logic: See Guideline B-2: Extract Even "Trivial" Arithmetic in Calculation-Heavy Projects in the core guide — applies the SSoT principle to shared math utilities in number-critical projects, with a concrete percent.ts case.

Async/Await Edge Cases

Parallel vs Sequential Execution

Problem: Unnecessary sequential execution of independent asynchronous operations.

Anti-pattern: Sequential execution of independent calls

// Total: 3s (1s each)
const user = await fetchUser(id);
const profile = await fetchProfile(id);
const settings = await fetchSettings(id);

Solution: Use Promise.all for parallel execution

// Total: 1s (all in parallel)
const [user, profile, settings] = await Promise.all([
    fetchUser(id),
    fetchProfile(id),
    fetchSettings(id),