初始化 NPM 项目
mkdir project-name
cd project-name
npm init添加开发基础包
添加 TypeScript
yarn add typescript -D添加 Jest 测试工具
yarn add jest ts-jest @types/jest -D添加 @types/node
yarn add @types/node -D初始化 TypeScript 配置
./node_modules/.bin/tsc --init这会在你的项目根目录新建一个 tsconfig.json 文件
现在的目录结构如下：
.
├── node_modules
├── package.json
├── tsconfig.json
└── yarn.lock文件解析
tsconfig.json
这是 TypeScript 的配置文件，默认仅启用了几项，我一般的配置如下：
{
"compilerOptions": {
/* Basic Options */
"target": "es5" /* Specify ECMAScript target version: 'ES3' (default), 'ES5', 'ES2015', 'ES2016', 'ES2017', 'ES2018', 'ES2019' or 'ESNEXT'. */,
"module": "commonjs" /* Specify module code generation: 'none', 'commonjs', 'amd', 'system', 'umd', 'es2015', or 'ESNext'. */,
"lib": [
"es6"
] /* Specify library files to be included in the compilation. */,
// "allowJs": true, /* Allow javascript files to be compiled. */
// "checkJs": true, /* Report errors in .js files. */
// "jsx": "preserve", /* Specify JSX code generation: 'preserve', 'react-native', or 'react'. */
"declaration": true /* Generates corresponding '.d.ts' file. */,
"declarationMap": true /* Generates a sourcemap for each corresponding '.d.ts' file. */,
// "sourceMap": true, /* Generates corresponding '.map' file. */
// "outFile": "./", /* Concatenate and emit output to single file. */
"outDir": "./dist" /* Redirect output structure to the directory. */,
// "rootDir": "./", /* Specify the root directory of input files. Use to control the output directory structure with --outDir. */
// "composite": true, /* Enable project compilation */
// "incremental": true, /* Enable incremental compilation */
// "tsBuildInfoFile": "./", /* Specify file to store incremental compilation information */
// "removeComments": true, /* Do not emit comments to output. */
// "noEmit": true, /* Do not emit outputs. */
// "importHelpers": true, /* Import emit helpers from 'tslib'. */
// "downlevelIteration": true, /* Provide full support for iterables in 'for-of', spread, and destructuring when targeting 'ES5' or 'ES3'. */
// "isolatedModules": true, /* Transpile each file as a separate module (similar to 'ts.transpileModule'). */
/* Strict Type-Checking Options */
"strict": true /* Enable all strict type-checking options. */,
"noImplicitAny": true /* Raise error on expressions and declarations with an implied 'any' type. */,
"strictNullChecks": true /* Enable strict null checks. */,
"strictFunctionTypes": true /* Enable strict checking of function types. */,
"strictBindCallApply": true /* Enable strict 'bind', 'call', and 'apply' methods on functions. */,
"strictPropertyInitialization": true /* Enable strict checking of property initialization in classes. */,
"noImplicitThis": true /* Raise error on 'this' expressions with an implied 'any' type. */,
"alwaysStrict": true /* Parse in strict mode and emit "use strict" for each source file. */,
/* Additional Checks */
"noUnusedLocals": true /* Report errors on unused locals. */,
"noUnusedParameters": true /* Report errors on unused parameters. */,
"noImplicitReturns": true /* Report error when not all code paths in function return a value. */,
"noFallthroughCasesInSwitch": true /* Report errors for fallthrough cases in switch statement. */,
/* Module Resolution Options */
// "moduleResolution": "node", /* Specify module resolution strategy: 'node' (Node.js) or 'classic' (TypeScript pre-1.6). */
// "baseUrl": "./", /* Base directory to resolve non-absolute module names. */
// "paths": {}, /* A series of entries which re-map imports to lookup locations relative to the 'baseUrl'. */
// "rootDirs": [], /* List of root folders whose combined content represents the structure of the project at runtime. */
// "typeRoots": [], /* List of folders to include type definitions from. */
// "types": [], /* Type declaration files to be included in compilation. */
// "allowSyntheticDefaultImports": true, /* Allow default imports from modules with no default export. This does not affect code emit, just typechecking. */
"esModuleInterop": true /* Enables emit interoperability between CommonJS and ES Modules via creation of namespace objects for all imports. Implies 'allowSyntheticDefaultImports'. */
// "preserveSymlinks": true, /* Do not resolve the real path of symlinks. */
/* Source Map Options */
// "sourceRoot": "", /* Specify the location where debugger should locate TypeScript files instead of source locations. */
// "mapRoot": "", /* Specify the location where debugger should locate map files instead of generated locations. */
// "inlineSourceMap": true, /* Emit a single file with source maps instead of having a separate file. */
// "inlineSources": true, /* Emit the source alongside the sourcemaps within a single file; requires '--inlineSourceMap' or '--sourceMap' to be set. */
/* Experimental Options */
// "experimentalDecorators": true, /* Enables experimental support for ES7 decorators. */
// "emitDecoratorMetadata": true, /* Enables experimental support for emitting type metadata for decorators. */
},
"include": ["./src/**/*"],
"exclude": ["node_modules", "src/__tests__"]
}package.json
添加了几条 scripts：
{
"name": "project-name",
"version": "0.0.0-development",
"description": "",
"main": "index.js",
"scripts": {
"build": "rm -rf ./dist && tsc",
"watch": "yarn test --watch",
"setup": "yarn install && npx npm-install-peers",
"test": "jest"
},
"author": "",
"license": "SEE LICENSE IN LICENSE FILE",
"devDependencies": {
"@types/jest": "^24.0.13",
"@types/node": "^12.0.3",
"jest": "^24.8.0",
"ts-jest": "^24.0.2",
"typescript": "^3.4.5"
}
}
添加 jest.config.js 文件
内容如下：
module.exports = {
// We always recommend having all TypeScript files in a src folder in your project. We assume this is true and specify this using the roots option.
roots: ["<rootDir>/src"],
transform: {
"^.+\\.tsx?$": "ts-jest" //The transform config just tells jest to use ts-jest for ts / tsx files.
}
};添加 .gitignore 文件
该文件告诉 git 哪些文件不需要跟踪
# Logs
logs
*.log
npm-debug.log*
yarn-debug.log*
yarn-error.log*
# Runtime data
pids
*.pid
*.seed
*.pid.lock
# Directory for instrumented libs generated by jscoverage/JSCover
lib-cov
# Coverage directory used by tools like istanbul
coverage
# nyc test coverage
.nyc_output
# Grunt intermediate storage (http://gruntjs.com/creating-plugins#storing-task-files)
.grunt
# Bower dependency directory (https://bower.io/)
bower_components
# node-waf configuration
.lock-wscript
# Compiled binary addons (https://nodejs.org/api/addons.html)
build/Release
# Dependency directories
node_modules/
jspm_packages/
# TypeScript v1 declaration files
typings/
# Optional npm cache directory
.npm
# Optional eslint cache
.eslintcache
# Optional REPL history
.node_repl_history
# Output of 'npm pack'
*.tgz
# Yarn Integrity file
.yarn-integrity
# dotenv environment variables file
.env
# next.js build output
.next
# map
*.map
# gitbook
_book初始化 git 项目
git init
jest watch需要有
git环境才能运行
添加 src/index.ts 文件
内容如下：
export const sum = (a: number, b: number): number => a + b;添加 src/__tests__
按我们的 jest 测试用例：src/__tests__/index.test.ts，内容如下：
import { sum } from "..";
test("sum", () => {
expect(sum(1, 2)).toBe(3);
});开始开发
yarn jest此时终端显示如下信息：
PASS src/__tests__/index.test.ts
✓ sum (15ms)
Test Suites: 1 passed, 1 total
Tests: 1 passed, 1 total
Snapshots: 0 total
Time: 2.133s
Ran all test suites related to changed files.
Watch Usage
› Press a to run all tests.
› Press f to run only failed tests.
› Press p to filter by a filename regex pattern.
› Press t to filter by a test name regex pattern.
› Press q to quit watch mode.
› Press Enter to trigger a test run.现在修改一下 index.ts，文件内容改为下面这样：
export const sum = (a: number, b: number): number => a + b;
export const multiply = (a: number, b: number): number => a * b;再修改 __tests__/index.test.ts，内容如下：
import { sum, multiply } from "..";
test("sum", () => {
expect(sum(1, 2)).toBe(3);
});
test("multiply", () => {
expect(multiply(2, 3)).toBe(6);
});会发现终端会自动测试你的代码：
PASS src/__tests__/index.test.ts
✓ sum (4ms)
✓ multiply
Test Suites: 1 passed, 1 total
Tests: 2 passed, 2 total
Snapshots: 0 total
Time: 4.164s
Ran all test suites related to changed files.完整的代码可以在下面看到：
