Back to Details

refactor

Compare original and translation side by side

🇺🇸

Original

English
🇨🇳

Translation

Chinese

Refactor Skill

重构技能

Improve the code structure without changing external behavior.
在不改变外部行为的前提下优化代码结构。

Step 1 — Understand the Goal

步骤1 — 明确目标

Ask or infer:
  • What is wrong with the current code? (too long, duplicated, wrong layer, hard to test)
  • What is the desired outcome? (extracted function, renamed variable, moved to correct layer)
  • Are there tests in place? (if not, write characterization tests before refactoring)
询问或推断：
  • 当前代码存在哪些问题？（过长、重复、层级错误、难以测试）
  • 期望达成什么结果？（提取函数、重命名变量、移至正确层级）
  • 是否已有测试用例？（如果没有，在重构前编写特征测试）

Step 2 — Establish a Safety Net

步骤2 — 构建安全保障

Before changing anything, verify tests exist that cover the code being refactored. If tests are missing, write characterization tests first:
  • A characterization test captures current behavior (even if the behavior is wrong).
  • It prevents accidental behavior changes during refactoring.
在进行任何修改前，确认待重构代码已有测试覆盖。 如果缺少测试，先编写特征测试：
  • 特征测试会捕捉当前行为（即使该行为是错误的）。
  • 它能防止重构过程中意外改变行为。

Step 3 — Apply Refactoring in Small Steps

步骤3 — 分步实施重构

Work in small, safe increments. After each step, verify tests still pass:
Common refactoring moves:
  • Extract function/method: identify a coherent chunk of logic with a clear purpose.
  • Rename: choose a name that accurately describes the thing at the current abstraction level.
  • Move to correct layer: domain logic in a controller → move to use case or domain service.
  • Replace conditional with polymorphism: complex switch/if chains on type → strategy pattern.
  • Introduce value object: raw primitive used to represent a domain concept → wrap it.
  • Remove duplication: extract shared logic to a shared function; do not abstract prematurely.
以小步、安全的增量方式推进。每完成一步，验证测试仍能通过：
常见重构操作：
  • 提取函数/方法：识别出具有明确用途的连贯逻辑块。
  • 重命名：选择能准确描述当前抽象层级下事物的名称。
  • 移至正确层级：将控制器中的领域逻辑移至用例或领域服务。
  • 用多态替代条件语句：将基于类型的复杂switch/if链替换为策略模式。
  • 引入值对象：将用于表示领域概念的原始基础类型进行封装。
  • 消除重复：将共享逻辑提取到共享函数中；避免过早抽象。

Step 4 — Verify Behavior is Unchanged

步骤4 — 验证行为未改变

After refactoring:
  • All tests pass.
  • The public API (exported signatures) is unchanged.
  • No new dependencies introduced.
重构完成后：
  • 所有测试通过。
  • 公共API（导出签名）保持不变。
  • 未引入新依赖。

Step 5 — Summarize

步骤5 — 总结

undefined
undefined

Refactor Summary

Refactor Summary

What changed: [List of moves applied] Why: [The design problem that was addressed] Tests: [Pass / added N new characterization tests] Breaking changes: None (internal only)
undefined
What changed: [List of moves applied] Why: [The design problem that was addressed] Tests: [Pass / added N new characterization tests] Breaking changes: None (internal only)
undefined