技能库智客分类：写作与研究 javascript-typescript-jest

Javascript Typescript Jest

使用 Jest 编写 JavaScript/ TypeScript 测试的最佳做法,包括模拟策略,测试结构,以及常见模式.

13160 安装量

官方网址：skills.sh

技能介绍

先看中文介绍；官方 description 原文单独保留，不改写 SKILL.md。

做什么

使用 Jest 编写 JavaScript/ TypeScript 测试的最佳做法,包括模拟策略,测试结构,以及常见模式.

何时用

官方 description 未单独写出 Use when。按规范，代理会在用户任务与这段 description 的关键词匹配时激活本技能。

代理如何加载

按 Agent Skills 渐进披露：启动时只加载 name 与 description（约 100 token）；任务匹配后才读入整份 SKILL.md 正文；scripts/、references/、assets/ 仅在需要时再读。本文件正文结构：Test Structure、Effective Mocking、Testing Async Code、Snapshot Testing、Testing React Components、Common Jest Matchers。

文件分析

文件分析：这是一份仅含 SKILL.md 的指令型技能，代理激活后整份正文进入上下文。

官方 description（原文）

Best practices for writing JavaScript/TypeScript tests using Jest, including mocking strategies, test structure, and common patterns.

Test StructureEffective MockingTesting Async CodeSnapshot TestingTesting React ComponentsCommon Jest Matchers

来源分类：skills.sh agent-skill

来源与网址

市场来源：skills.sh

GitHub 完整包

开源榜 Skill 分类

SKILL.md 与 Agent 调用

官方规范 ↗

name: javascript-typescript-jest
description: Best practices for writing JavaScript/TypeScript tests using Jest, including mocking strategies, test structure, and common patterns.

发现技能客户端向 Agent 提供名称与描述目录。
匹配与调用用户指定或任务匹配后，载入 SKILL.md 指令。
按需加载按步骤读取参考文档、使用脚本与素材。

具体调用语法与可用工具以目标 Agent 客户端为准。查看调用机制说明 ↗

安装这个技能

Skills CLI ↗

先选择目标 Agent 和安装范围，保留技能包的附属文件，安装后检查客户端能否发现该技能。

交给 Agent 安装

复制安装指令给支持 Agent Skills 的代理，确认其中的目标目录与客户端匹配。

把 Agent Skill「javascript-typescript-jest」安装到我的项目：SKILL.md 原文与官方 description 见 https://zicq.com/zh/skills/skl-66667817e9ccfd9a-Javascript-Typescript-Jest.html
请存为 .cursor/skills/javascript-typescript-jest/SKILL.md 或 .claude/skills/javascript-typescript-jest/SKILL.md，frontmatter 的 name 与 description 保持原样，不要改写。

GitHub 完整包 ↗

终端安装 · Skills CLI

需要 Node.js 与 npx。先查看仓库技能列表，确认实际名称。

npx skills add 'https://github.com/github/awesome-copilot' --list

目标客户端安装范围

npx skills add 'https://github.com/github/awesome-copilot' --skill 'javascript-typescript-jest'

CLI 会交互选择目标 Agent，默认安装到项目；用户级安装使用 -g。先通过查看命令核对仓库内容，再用 npx skills list 检查已安装技能。

SKILL.md 原文可复制，不会改动源文件

---
name: javascript-typescript-jest
description: 'Best practices for writing JavaScript/TypeScript tests using Jest, including mocking strategies, test structure, and common patterns.'
---

### Test Structure
- Name test files with `.test.ts` or `.test.js` suffix
- Place test files next to the code they test or in a dedicated `__tests__` directory
- Use descriptive test names that explain the expected behavior
- Use nested describe blocks to organize related tests
- Follow the pattern: `describe('Component/Function/Class', () => { it('should do something', () => {}) })`

### Effective Mocking
- Mock external dependencies (APIs, databases, etc.) to isolate your tests
- Use `jest.mock()` for module-level mocks
- Use `jest.spyOn()` for specific function mocks
- Use `mockImplementation()` or `mockReturnValue()` to define mock behavior
- Reset mocks between tests with `jest.resetAllMocks()` in `afterEach`

### Testing Async Code
- Always return promises or use async/await syntax in tests
- Use `resolves`/`rejects` matchers for promises
- Set appropriate timeouts for slow tests with `jest.setTimeout()`

### Snapshot Testing
- Use snapshot tests for UI components or complex objects that change infrequently
- Keep snapshots small and focused
- Review snapshot changes carefully before committing

### Testing React Components
- Use React Testing Library over Enzyme for testing components
- Test user behavior and component accessibility
- Query elements by accessibility roles, labels, or text content
- Use `userEvent` over `fireEvent` for more realistic user interactions

## Common Jest Matchers
- Basic: `expect(value).toBe(expected)`, `expect(value).toEqual(expected)`
- Truthiness: `expect(value).toBeTruthy()`, `expect(value).toBeFalsy()`
- Numbers: `expect(value).toBeGreaterThan(3)`, `expect(value).toBeLessThanOrEqual(3)`
- Strings: `expect(value).toMatch(/pattern/)`, `expect(value).toContain('substring')`
- Arrays: `expect(array).toContain(item)`, `expect(array).toHaveLength(3)`
- Objects: `expect(object).toHaveProperty('key', value)`
- Exceptions: `expect(fn).toThrow()`, `expect(fn).toThrow(Error)`
- Mock functions: `expect(mockFn).toHaveBeenCalled()`, `expect(mockFn).toHaveBeenCalledWith(arg1, arg2)`

阅读排版

name: javascript-typescript-jest description: 'Best practices for writing JavaScript/TypeScript tests using Jest, including mocking strategies, test structure, and common patterns.'

Test Structure

Name test files with .test.ts or .test.js suffix
Place test files next to the code they test or in a dedicated __tests__ directory
Use descriptive test names that explain the expected behavior
Use nested describe blocks to organize related tests
Follow the pattern: describe('Component/Function/Class', () => { it('should do something', () => {}) })

Effective Mocking

Mock external dependencies (APIs, databases, etc.) to isolate your tests
Use jest.mock() for module-level mocks
Use jest.spyOn() for specific function mocks
Use mockImplementation() or mockReturnValue() to define mock behavior
Reset mocks between tests with jest.resetAllMocks() in afterEach

Testing Async Code

Always return promises or use async/await syntax in tests
Use resolves/rejects matchers for promises
Set appropriate timeouts for slow tests with jest.setTimeout()

Snapshot Testing

Use snapshot tests for UI components or complex objects that change infrequently
Keep snapshots small and focused
Review snapshot changes carefully before committing

Testing React Components

Use React Testing Library over Enzyme for testing components
Test user behavior and component accessibility
Query elements by accessibility roles, labels, or text content
Use userEvent over fireEvent for more realistic user interactions

Common Jest Matchers

Basic: expect(value).toBe(expected), expect(value).toEqual(expected)
Truthiness: expect(value).toBeTruthy(), expect(value).toBeFalsy()
Numbers: expect(value).toBeGreaterThan(3), expect(value).toBeLessThanOrEqual(3)
Strings: expect(value).toMatch(/pattern/), expect(value).toContain('substring')
Arrays: expect(array).toContain(item), expect(array).toHaveLength(3)
Objects: expect(object).toHaveProperty('key', value)
Exceptions: expect(fn).toThrow(), expect(fn).toThrow(Error)
Mock functions: expect(mockFn).toHaveBeenCalled(), expect(mockFn).toHaveBeenCalledWith(arg1, arg2)