Addy Osmani 增量实施

增量实施：addyosmani/agent-skills: incremental-implementatio，适用于工程实践、代码质量与开发流程优化。

Skill Documentation

Addy Osmani 增量实施

摘要

增量实施：addyosmani/agent-skills: incremental-implementatio，适用于工程实践、代码质量与开发流程优化。

> 来源: addyosmani/agent-skills — Google Chrome 团队领袖 Addy Osmani

> 原文件: skills/incremental-implementation/SKILL.md

> 模型推荐: 看 skill 类型挑

这个 skill 是干嘛的

Addy Osmani (Google Chrome 团队 Performance Lead,前端工程领域权威) 整理的 24 个工程方法论 skill 集合 — 覆盖 API 设计 / 浏览器测试 / CI/CD / 代码评审 / TDD / 安全 / 性能 / 部署 等。

michael 强调"skill 要有相应的指导功能,指导用户使用",所以加了下面两节让 Agent 和用户对接。

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🤖 Agent 使用说明

1. 接到任务后,先按这个 skill 的触发关键词跑

2. 跑 Checklist 一遍,标记红线步骤

3. 红线步骤必须先完成(往往是 ask user 确认)

4. 完工前用 verification step 自检

5. 跑完了告诉用户结果,不要自行提交

👤 用户需要做什么?

1. 告诉 Agent 你要做什么(一句话即可)

2. 如果 skill 要求 ask user 凭证 / OAuth / 部署密钥,按提示提供

3. 完工后让 Agent 跑自检再交回

4. 全程 Agent 自动化,你只需回答"是/否"类决策点

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原 skill 内容(addyosmani/agent-skills/incremental-implementation/SKILL.md,截断到 12k chars)

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name: incremental-implementation

description: Delivers changes incrementally. Use when implementing any feature or change that touches more than one file. Use when you're about to write a large amount of code at once, or when a task feels too big to land in one step.

---

Incremental Implementation

Overview

Build in thin vertical slices — implement one piece, test it, verify it, then expand. Avoid implementing an entire feature in one pass. Each increment should leave the system in a working, testable state. This is the execution discipline that makes large features manageable.

When to Use

• Implementing any multi-file change
• Building a new feature from a task breakdown
• Refactoring existing code
• Any time you're tempted to write more than ~100 lines before testing

**When NOT to use:** Single-file, single-function changes where the scope is already minimal.

The Increment Cycle

┌──────────────────────────────────────┐
│                                      │
│   Implement ──→ Test ──→ Verify ──┐  │
│       ▲                           │  │
│       └───── Commit ◄─────────────┘  │
│              │                       │
│              ▼                       │
│          Next slice                  │
│                                      │
└──────────────────────────────────────┘

For each slice:

1. **Implement** the smallest complete piece of functionality

2. **Test** — run the test suite (or write a test if none exists)

3. **Verify** — confirm the slice works as expected (tests pass, build succeeds, manual check)

4. **Commit** -- save your progress with a descriptive message (see `git-workflow-and-versioning` for atomic commit guidance)

5. **Move to the next slice** — carry forward, don't restart

Slicing Strategies

Vertical Slices (Preferred)

Build one complete path through the stack:

Slice 1: Create a task (DB + API + basic UI)
    → Tests pass, user can create a task via the UI

Slice 2: List tasks (query + API + UI)
    → Tests pass, user can see their tasks

Slice 3: Edit a task (update + API + UI)
    → Tests pass, user can modify tasks

Slice 4: Delete a task (delete + API + UI + confirmation)
    → Tests pass, full CRUD complete

Each slice delivers working end-to-end functionality.

Contract-First Slicing

When backend and frontend need to develop in parallel:

Slice 0: Define the API contract (types, interfaces, OpenAPI spec)
Slice 1a: Implement backend against the contract + API tests
Slice 1b: Implement frontend against mock data matching the contract
Slice 2: Integrate and test end-to-end

Risk-First Slicing

Tackle the riskiest or most uncertain piece first:

Slice 1: Prove the WebSocket connection works (highest risk)
Slice 2: Build real-time task updates on the proven connection
Slice 3: Add offline support and reconnection

If Slice 1 fails, you discover it before investing in Slices 2 and 3.

Implementation Rules

Rule 0: Simplicity First

Before writing any code, ask: "What is the simplest thing that could work?"

After writing code, review it against these checks:

• Can this be done in fewer lines?
• Are these abstractions earning their complexity?
• Would a staff engineer look at this and say "why didn't you just..."?
• Am I building for hypothetical future requirements, or the current task?

SIMPLICITY CHECK:
✗ Generic EventBus with middleware pipeline for one notification
✓ Simple function call

✗ Abstract factory pattern for two similar components
✓ Two straightforward components with shared utilities

✗ Config-driven form builder for three forms
✓ Three form components

Three similar lines of code is better than a premature abstraction. Implement the naive, obviously-correct version first. Optimize only after correctness is proven with tests.

Rule 0.5: Scope Discipline

Touch only what the task requires.

Do NOT:

• "Clean up" code adjacent to your change
• Refactor imports in files you're not modifying
• Remove comments you don't fully understand
• Add features not in the spec because they "seem useful"
• Modernize syntax in files you're only reading

If you notice something worth improving outside your task scope, note it — don't fix it:

NOTICED BUT NOT TOUCHING:
- src/utils/format.ts has an unused import (unrelated to this task)
- The auth middleware could use better error messages (separate task)
→ Want me to create tasks for these?

Rule 1: One Thing at a Time

Each increment changes one logical thing. Don't mix concerns:

**Bad:** One commit that adds a new component, refactors an existing one, and updates the build config.

**Good:** Three separate commits — one for each change.

Rule 2: Keep It Compilable

After each increment, the project must build and existing tests must pass. Don't leave the codebase in a broken state between slices.

Rule 3: Feature Flags for Incomplete Features

If a feature isn't ready for users but you need to merge increments:

// Feature flag for work-in-progress
const ENABLE_TASK_SHARING = process.env.FEATURE_TASK_SHARING === 'true';

if (ENABLE_TASK_SHARING) {
  // New sharing UI
}

This lets you merge small increments to the main branch without exposing incomplete work.

Rule 4: Safe Defaults

New code should default to safe, conservative behavior:

// Safe: disabled by default, opt-in
export function createTask(data: TaskInput, options?: { notify?: boolean }) {
  const shouldNotify = options?.notify ?? false;
  // ...
}

Rule 5: Rollback-Friendly

Each increment should be independently revertable:

• Additive changes (new files, new functions) are easy to revert
• Modifications to existing code should be minimal and focused
• Database migrations should have corresponding rollback migrations
• Avoid deleting something in one commit and replacing it in the same commit — separate them

Working with Agents

When directing an agent to implement incrementally:

"Let's implement Task 3 from the plan.

Start with just the database schema change and the API endpoint.
Don't touch the UI yet — we'll do that in the next increment.

After implementing, run the repository's test and build commands to
verify nothing is broken."

Be explicit about what's in scope and what's NOT in scope for each increment.

Increment Checklist

After each increment, verify with the repository's own commands (see the test-driven-development skill's Discover the Stack First section):

• [ ] The change does one thing and does it completely
• [ ] All existing tests still pass (the repository's test command: `npm test`, `./gradlew test`, `pytest`, ...)
• [ ] The build succeeds (the repository's build command)
• [ ] Type checking passes, where the stack has one (`npx tsc --noEmit`, `mypy`, ...)
• [ ] Linting passes (the repository's lint command)
• [ ] The new functionality works as expected
• [ ] The change is committed with a descriptive message

**Note:** Run each verification command after a change that could affect it. After a successful run, don't repeat the same command unless the code has changed since — re-running on unchanged code adds no information.

Common Rationalizations

| Rationalization | Reality |

|---|---|

| "I'll test it all at the end" | Bugs compound. A bug in Slice 1 makes Slices 2-5 wrong. Test each slice. |

| "It's faster to do it all at once" | It *feels* faster until something breaks and you can't find which of 500 changed lines caused it. |

| "These changes are too small to commit separately" | Small commits are free. Large commits hide bugs and make rollbacks painful. |

| "I'll add the feature flag later" | If the feature isn't complete, it shouldn't be user-visible. Add the flag now. |

| "This refactor is small enough to include" | Refactors mixed with features make both harder to review and debug. Separate them. |

| "Let me run the build command again just to be sure" | After a successful run, repeating the same command adds nothing unless the code has changed since. Run it again after subsequent edits, not as reassurance. |

Red Flags

• More than 100 lines of code written without running tests
• Multiple unrelated changes in a single increment
• "Let me just quickly add this too" scope expansion
• Skipping the test/verify step to move faster
• Build or tests broken between increments
• Large uncommitted changes accumulating
• Building abstractions before the third use case demands it
• Touching files outside the task scope "while I'm here"
• Creating new utility files for one-time operations
• Running the same build/test command twice in a row without any intervening code change

Verification

After completing all increments for a task:

• [ ] Each increment was individually tested and committed
• [ ] The full test suite passes
• [ ] The build is clean
• [ ] The feature works end-to-end as specified
• [ ] No uncommitted changes remain

See Also

Per-increment verification is the local check. Before declaring a task done, apply the project-wide Definition of Done as the final gate, the standing bar every increment clears regardless of the task. See `../../references/definition-of-done.md`.

常见问题（FAQ）

使用「增量实施」这个 skill 能解决什么问题?

本 skill 专注于增量实施，addyosmani/agent-skills: incremental-implementation。它将相关流程标准化，帮助用户更快拿到可靠结果，减少重复手工操作。

什么情况下适合使用「增量实施」?

当你需要在增量实施相关工作中获得稳定、可复用的产出时最适合——无论是单次任务还是纳入日常工作流，都能直接调用。

使用「增量实施」前需要准备什么?

需要一个具体的项目或任务上下文，最好带有代码仓库或需求文档。