写在前面
前几个月在公司用vue3 https://v3.vuejs.org/和ts写项目，想巩固一下基础，于是我想起了去年基于JavaScript和Jest搭建的刷题环境https://zhengjiangtao.cn/coding，不如，给它搞个加强版，结合Typescript和Jest https://jestjs.io/搞一个刷题环境https://zhengjiangtao.cn/coding-ts/，下面是我的一些使用心得，分享给大家。
介绍
Typescript是JavaScript的超集https://www.typescriptlang.org/，是前端工程师需要掌握的一门语言。Jest是一个测试框架，具体的可以看我早年写的文章https://www.cnblogs.com/cnroadbridge/p/13524099.html， Babel是一个语言编译器，具体的也可以看我早年写的文章https://www.cnblogs.com/cnroadbridge/p/13311360.html。
环境搭建
前期工作
这里统一用yarn https://yarnpkg.com/来进行相关的npm 包https://www.npmjs.com/安装与维护，使用其他安装管理工具的参照着这个改吧。
创建项目并初始化
代码语言：javascript复制mkdir coding-ts && cd coding-ts
npm init -y
安装ts的开发环境依赖
代码语言：javascript复制yarn add typescript ts-node @types/node -D
配置tsconfig.json
代码语言：javascript复制{
"compilerOptions": {
/* Visit https://aka.ms/tsconfig.json to read more about this file */
/* Projects */
// "incremental": true, /* Enable incremental compilation */
// "composite": true, /* Enable constraints that allow a TypeScript project to be used with project references. */
// "tsBuildInfoFile": "./", /* Specify the folder for .tsbuildinfo incremental compilation files. */
// "disableSourceOfProjectReferenceRedirect": true, /* Disable preferring source files instead of declaration files when referencing composite projects */
// "disableSolutionSearching": true, /* Opt a project out of multi-project reference checking when editing. */
// "disableReferencedProjectLoad": true, /* Reduce the number of projects loaded automatically by TypeScript. */
/* Language and Environment */
"target": "es2016", /* Set the JavaScript language version for emitted JavaScript and include compatible library declarations. */
// "lib": [], /* Specify a set of bundled library declaration files that describe the target runtime environment. */
// "jsx": "preserve", /* Specify what JSX code is generated. */
// "experimentalDecorators": true, /* Enable experimental support for TC39 stage 2 draft decorators. */
// "emitDecoratorMetadata": true, /* Emit design-type metadata for decorated declarations in source files. */
// "jsxFactory": "", /* Specify the JSX factory function used when targeting React JSX emit, e.g. 'React.createElement' or 'h' */
// "jsxFragmentFactory": "", /* Specify the JSX Fragment reference used for fragments when targeting React JSX emit e.g. 'React.Fragment' or 'Fragment'. */
// "jsxImportSource": "", /* Specify module specifier used to import the JSX factory functions when using `jsx: react-jsx*`.` */
// "reactNamespace": "", /* Specify the object invoked for `createElement`. This only applies when targeting `react` JSX emit. */
// "noLib": true, /* Disable including any library files, including the default lib.d.ts. */
// "useDefineForClassFields": true, /* Emit ECMAScript-standard-compliant class fields. */
/* Modules */
"module": "commonjs", /* Specify what module code is generated. */
// "rootDir": "./", /* Specify the root folder within your source files. */
// "moduleResolution": "node", /* Specify how TypeScript looks up a file from a given module specifier. */
// "baseUrl": "./", /* Specify the base directory to resolve non-relative module names. */
// "paths": {}, /* Specify a set of entries that re-map imports to additional lookup locations. */
// "rootDirs": [], /* Allow multiple folders to be treated as one when resolving modules. */
// "typeRoots": [], /* Specify multiple folders that act like `./node_modules/@types`. */
// "types": [], /* Specify type package names to be included without being referenced in a source file. */
// "allowUmdGlobalAccess": true, /* Allow accessing UMD globals from modules. */
// "resolveJsonModule": true, /* Enable importing .json files */
// "noResolve": true, /* Disallow `import`s, `require`s or `<reference>`s from expanding the number of files TypeScript should add to a project. */
/* JavaScript Support */
// "allowJs": true, /* Allow JavaScript files to be a part of your program. Use the `checkJS` option to get errors from these files. */
// "checkJs": true, /* Enable error reporting in type-checked JavaScript files. */
// "maxNodeModuleJsDepth": 1, /* Specify the maximum folder depth used for checking JavaScript files from `node_modules`. Only applicable with `allowJs`. */
/* Emit */
// "declaration": true, /* Generate .d.ts files from TypeScript and JavaScript files in your project. */
// "declarationMap": true, /* Create sourcemaps for d.ts files. */
// "emitDeclarationOnly": true, /* Only output d.ts files and not JavaScript files. */
"sourceMap": true, /* Create source map files for emitted JavaScript files. */
// "outFile": "./", /* Specify a file that bundles all outputs into one JavaScript file. If `declaration` is true, also designates a file that bundles all .d.ts output. */
"outDir": "dist", /* Specify an output folder for all emitted files. */
// "removeComments": true, /* Disable emitting comments. */
// "noEmit": true, /* Disable emitting files from a compilation. */
// "importHelpers": true, /* Allow importing helper functions from tslib once per project, instead of including them per-file. */
// "importsNotUsedAsValues": "remove", /* Specify emit/checking behavior for imports that are only used for types */
// "downlevelIteration": true, /* Emit more compliant, but verbose and less performant JavaScript for iteration. */
// "sourceRoot": "", /* Specify the root path for debuggers to find the reference source code. */
// "mapRoot": "", /* Specify the location where debugger should locate map files instead of generated locations. */
// "inlineSourceMap": true, /* Include sourcemap files inside the emitted JavaScript. */
// "inlineSources": true, /* Include source code in the sourcemaps inside the emitted JavaScript. */
// "emitBOM": true, /* Emit a UTF-8 Byte Order Mark (BOM) in the beginning of output files. */
// "newLine": "crlf", /* Set the newline character for emitting files. */
// "stripInternal": true, /* Disable emitting declarations that have `@internal` in their JSDoc comments. */
// "noEmitHelpers": true, /* Disable generating custom helper functions like `__extends` in compiled output. */
// "noEmitOnError": true, /* Disable emitting files if any type checking errors are reported. */
// "preserveConstEnums": true, /* Disable erasing `const enum` declarations in generated code. */
// "declarationDir": "./", /* Specify the output directory for generated declaration files. */
// "preserveValueImports": true, /* Preserve unused imported values in the JavaScript output that would otherwise be removed. */
/* Interop Constraints */
// "isolatedModules": true, /* Ensure that each file can be safely transpiled without relying on other imports. */
// "allowSyntheticDefaultImports": true, /* Allow 'import x from y' when a module doesn't have a default export. */
"esModuleInterop": true, /* Emit additional JavaScript to ease support for importing CommonJS modules. This enables `allowSyntheticDefaultImports` for type compatibility. */
// "preserveSymlinks": true, /* Disable resolving symlinks to their realpath. This correlates to the same flag in node. */
"forceConsistentCasingInFileNames": true, /* Ensure that casing is correct in imports. */
/* Type Checking */
"strict": true, /* Enable all strict type-checking options. */
// "noImplicitAny": true, /* Enable error reporting for expressions and declarations with an implied `any` type.. */
// "strictNullChecks": true, /* When type checking, take into account `null` and `undefined`. */
// "strictFunctionTypes": true, /* When assigning functions, check to ensure parameters and the return values are subtype-compatible. */
// "strictBindCallApply": true, /* Check that the arguments for `bind`, `call`, and `apply` methods match the original function. */
// "strictPropertyInitialization": true, /* Check for class properties that are declared but not set in the constructor. */
// "noImplicitThis": true, /* Enable error reporting when `this` is given the type `any`. */
// "useUnknownInCatchVariables": true, /* Type catch clause variables as 'unknown' instead of 'any'. */
// "alwaysStrict": true, /* Ensure 'use strict' is always emitted. */
// "noUnusedLocals": true, /* Enable error reporting when a local variables aren't read. */
// "noUnusedParameters": true, /* Raise an error when a function parameter isn't read */
// "exactOptionalPropertyTypes": true, /* Interpret optional property types as written, rather than adding 'undefined'. */
// "noImplicitReturns": true, /* Enable error reporting for codepaths that do not explicitly return in a function. */
// "noFallthroughCasesInSwitch": true, /* Enable error reporting for fallthrough cases in switch statements. */
// "noUncheckedIndexedAccess": true, /* Include 'undefined' in index signature results */
// "noImplicitOverride": true, /* Ensure overriding members in derived classes are marked with an override modifier. */
// "noPropertyAccessFromIndexSignature": true, /* Enforces using indexed accessors for keys declared using an indexed type */
// "allowUnusedLabels": true, /* Disable error reporting for unused labels. */
// "allowUnreachableCode": true, /* Disable error reporting for unreachable code. */
/* Completeness */
// "skipDefaultLibCheck": true, /* Skip type checking .d.ts files that are included with TypeScript. */
"skipLibCheck": true /* Skip type checking all .d.ts files. */
}
}
这里也可以用tsc --init来初始化, 需要你全局安装typescript这个包
安装jest的开发环境依赖
代码语言：javascript复制yarn add jest ts-jest @types/jest -D
配置jest.config.js
代码语言：javascript复制/** @type {import('ts-jest/dist/types').InitialOptionsTsJest} */
/*
* For a detailed explanation regarding each configuration property, visit:
* https://jestjs.io/docs/en/configuration.html
*/
module.exports = {
// All imported modules in your tests should be mocked automatically
// automock: false,
// Stop running tests after `n` failures
// bail: 0,
// The directory where Jest should store its cached dependency information
// cacheDirectory: "/private/var/folders/6j/_9wqvbk15bl701f7ch11q9p80000gn/T/jest_dx",
// Automatically clear mock calls and instances between every test
clearMocks: true,
// Indicates whether the coverage information should be collected while executing the test
// collectCoverage: false,
// An array of glob patterns indicating a set of files for which coverage information should be collected
// collectCoverageFrom: undefined,
// The directory where Jest should output its coverage files
coverageDirectory: 'coverage',
// An array of regexp pattern strings used to skip coverage collection
// coveragePathIgnorePatterns: [
// "/node_modules/"
// ],
// Indicates which provider should be used to instrument code for coverage
// coverageProvider: "babel",
// A list of reporter names that Jest uses when writing coverage reports
// coverageReporters: [
// "json",
// "text",
// "lcov",
// "clover"
// ],
// An object that configures minimum threshold enforcement for coverage results
// coverageThreshold: undefined,
// A path to a custom dependency extractor
// dependencyExtractor: undefined,
// Make calling deprecated APIs throw helpful error messages
// errorOnDeprecated: false,
// Force coverage collection from ignored files using an array of glob patterns
// forceCoverageMatch: [],
// A path to a module which exports an async function that is triggered once before all test suites
// globalSetup: undefined,
// A path to a module which exports an async function that is triggered once after all test suites
// globalTeardown: undefined,
// A set of global variables that need to be available in all test environments
// globals: {},
// The maximum amount of workers used to run your tests. Can be specified as % or a number. E.g. maxWorkers: 10% will use 10% of your CPU amount 1 as the maximum worker number. maxWorkers: 2 will use a maximum of 2 workers.
// maxWorkers: "50%",
// An array of directory names to be searched recursively up from the requiring module's location
// moduleDirectories: [
// "node_modules"
// ],
// An array of file extensions your modules use
// moduleFileExtensions: [
// "js",
// "json",
// "jsx",
// "ts",
// "tsx",
// "node"
// ],
// A map from regular expressions to module names or to arrays of module names that allow to stub out resources with a single module
// moduleNameMapper: {},
// An array of regexp pattern strings, matched against all module paths before considered 'visible' to the module loader
// modulePathIgnorePatterns: [],
// Activates notifications for test results
// notify: false,
// An enum that specifies notification mode. Requires { notify: true }
// notifyMode: "failure-change",
// A preset that is used as a base for Jest's configuration
preset: 'ts-jest',
// Run tests from one or more projects
// projects: undefined,
// Use this configuration option to add custom reporters to Jest
// reporters: undefined,
// Automatically reset mock state between every test
// resetMocks: false,
// Reset the module registry before running each individual test
// resetModules: false,
// A path to a custom resolver
// resolver: undefined,
// Automatically restore mock state between every test
// restoreMocks: false,
// The root directory that Jest should scan for tests and modules within
// rootDir: undefined,
// A list of paths to directories that Jest should use to search for files in
// roots: [
// "<rootDir>"
// ],
// Allows you to use a custom runner instead of Jest's default test runner
// runner: "jest-runner",
// The paths to modules that run some code to configure or set up the testing environment before each test
// setupFiles: [],
// A list of paths to modules that run some code to configure or set up the testing framework before each test
// setupFilesAfterEnv: [],
// The number of seconds after which a test is considered as slow and reported as such in the results.
// slowTestThreshold: 5,
// A list of paths to snapshot serializer modules Jest should use for snapshot testing
// snapshotSerializers: [],
// The test environment that will be used for testing
testEnvironment: 'node',
// Options that will be passed to the testEnvironment
// testEnvironmentOptions: {},
// Adds a location field to test results
// testLocationInResults: false,
// The glob patterns Jest uses to detect test files
// testMatch: [
// "**/__tests__/**/*.[jt]s?(x)",
// "**/?(*.) (spec|test).[tj]s?(x)"
// ],
// An array of regexp pattern strings that are matched against all test paths, matched tests are skipped
// testPathIgnorePatterns: [
// "/node_modules/"
// ],
// The regexp pattern or array of patterns that Jest uses to detect test files
// testRegex: [],
// This option allows the use of a custom results processor
// testResultsProcessor: undefined,
// This option allows use of a custom test runner
// testRunner: "jasmine2",
// This option sets the URL for the jsdom environment. It is reflected in properties such as location.href
// testURL: "http://localhost",
// Setting this value to "fake" allows the use of fake timers for functions such as "setTimeout"
// timers: "real",
// A map from regular expressions to paths to transformers
// transform: undefined,
// An array of regexp pattern strings that are matched against all source file paths, matched files will skip transformation
// transformIgnorePatterns: [
// "/node_modules/",
// "\.pnp\.[^\/] $"
// ],
// An array of regexp pattern strings that are matched against all modules before the module loader will automatically return a mock for them
// unmockedModulePathPatterns: undefined,
// Indicates whether each individual test should be reported during the run
// verbose: undefined,
// An array of regexp patterns that are matched against all source file paths before re-running tests in watch mode
// watchPathIgnorePatterns: [],
// Whether to use watchman for file crawling
// watchman: true,
};
安装babel的开发环境依赖
代码语言：javascript复制yarn add babel-jest @babel/core @babel/preset-env @babel/preset-typescript -D
配置babel.config.js
代码语言：javascript复制module.exports = {
presets: [
['@babel/preset-env', { targets: { node: 'current' } }],
'@babel/preset-typescript',
],
};
具体的参考这里，https://jestjs.io/docs/getting-started
安装prettier 和 eslint的开发环境依赖
代码语言：javascript复制yarn add prettier onchange eslint-config-prettier eslint-plugin-prettier -D
配置.prettierrc和.prettierignore
.prettierrc
{
"semi": true,
"tabWidth": 2,
"printWidth": 120,
"endOfLine": "lf",
"singleQuote": true,
"trailingComma": "es5",
"bracketSpacing": true,
"alwaysParens": "always",
"eslintIntegration": true,
"jsxSingleQuote": true
}
.prettierignore
# Ignore artifacts:
coverage
# ignore dependency folder
node_modules/
配置.eslintrc
代码语言：javascript复制{
"root": true,
"parser": "@typescript-eslint/parser",
"plugins": [
"@typescript-eslint",
"prettier"
],
"extends": [
"eslint:recommended",
"plugin:@typescript-eslint/eslint-recommended",
"plugin:@typescript-eslint/recommended",
"prettier"
],
"rules": {
"no-console": 1, // Means warning
"prettier/prettier": 2 // Means error
}
}
具体的可以参考这里，https://khalilstemmler.com/blogs/tooling/prettier/
配置package.json的相关script
代码语言：javascript复制 "scripts": {
"build": "tsc",
"test": "jest",
"test:help": "jest --help",
"test:debug": "jest --debug",
"test:verbose": "jest --verbose",
"test:init": "jest --init",
"test:json": "jest --json",
"test:exportJson": "jest --json --outputFile=./export/reporter.json",
"test:coverage": "jest --coverage",
"test:watchAll": "jest --watchAll",
"pretty": "prettier --config .prettierrc "code/**/*.ts" --write",
"pretty-watch": "onchange "code/**/*.ts" -- prettier --write {{changed}}",
"git:pull": "pull",
"git:push": "push"
}
测试案例
这里以两数之和为例，做一个简单的代码测试，具体的如下：
源码
代码语言：javascript复制// code/sum.ts 两数之和测试案例
type sumType = (a: number, b: number) => number;
const sum: sumType = (a, b) => a b;
export default sum;
测试代码
代码语言：javascript复制// test/sum.test.ts
import sum from '../code/sum';
test('1 2 = 3', () => {
let x: number = 1, y: number = 2;
let expected: number = 3;
let res: number = sum(x, y);
expect(res).toBe(expected);
});
在项目文件下执行yarn test 我们查看下运行的效果
PS D:ataolagithubataolacoding-ts> yarn test
yarn run v1.22.11
$ jest
PASS test/sum.test.ts (8.801 s)
√ 1 2 = 3 (2 ms)
Test Suites: 1 passed, 1 total
Tests: 1 passed, 1 total
Snapshots: 0 total
Time: 10.721 s
Ran all test suites.
Done in 26.79s.
PS D:ataolagithubataolacoding-ts>
持续集成和代码覆盖率
Travis可以对项目做一个持续集成 https://app.travis-ci.com/github/ataola/coding-ts，结合Codecov，https://app.codecov.io/gh/ataola/coding-ts可以对代码覆盖率做一个测试，这样项目看上去就丰满了很多
关于Travis和Codecov的相关实践，具体的可以参见https://www.cnblogs.com/cnroadbridge/p/14716361.html
写在后面
项目地址：https://github.com/ataola/coding-ts
线上访问地址: https://zhengjiangtao.cn/coding-ts/
感谢阅读！
