为react typescript项目设置ts-jest

Question

我正在尝试为一个用typescript编写的react项目设置测试环境。我以前做过react，但用的是ES6。

下面是我的package.json的相关部分：

 "scripts": {
    "test": "NODE_ENV=test jest",
    "build": "webpack --mode production",
    "start": "webpack-dev-server --open --mode development"
  },
  "jest": {
    "moduleNameMapper": {
      "\\.(css)$": "jest-css-modules"
    },
    "transform": {
      "\\.(ts|tsx)$": "ts-jest"
    },
    "testRegex": ".test.(ts|tsx?)$",
    "moduleFileExensions": ["ts", "tsx", "js", "jsx", "json", "node"]
  },

我想提一下，我指望的是ts转译器，而根本没有配置babel。

以下是我包含的依赖项：

"dependencies": {
    "@types/jest": "^23.1.4",
    "@types/react": "^16.4.5",
    "@types/react-dom": "^16.0.6",
    "@types/react-redux": "^6.0.3",
    "@types/redux": "^3.6.0",
    "deep-freeze": "0.0.1",
    "jest": "^23.2.0",
    "jest-css-modules": "^1.1.0",
    "react-redux": "^5.0.7",
    "redux": "^4.0.0",
    "ts-jest": "^23.0.0",
    "webpack": "^4.12.2"
  },
  "devDependencies": {
    "awesome-typescript-loader": "^5.2.0",
    "css-loader": "^0.28.11",
    "html-loader": "^0.5.5",
    "html-webpack-plugin": "^3.2.0",
    "prop-types": "^15.6.2",
    "react": "^16.4.1",
    "react-dom": "^16.4.1",
    "style-loader": "^0.21.0",
    "typescript": "^2.9.2",
    "typings-for-css-modules-loader": "^1.7.0",
    "url-loader": "^1.0.1",
    "webpack-cli": "^3.0.8",
    "webpack-dev-server": "^3.1.4"
  }

当我运行npm run test时，我无法理解以下错误，因为我已经在转换中安装并指定了ts-jest -

Validation Error:

  Module ts-jest in the transform option was not found.
         <rootDir> is: /Users/rahul/ot/Lab/webpack-playlist

下面是tsconfig.json的外观

{
  "compilerOptions": {
    "jsx": "react",
    "noImplicitAny": true,
    "sourceMap": true,
    "target": "es5"
  }
}

不确定如何解决上面的错误。

我也尝试了在tsconfig.json中配置ts-jest，如下所示，但仍然给出了相同的错误-

// tsconfig.json
    "jest": {
        "globals": {
          "ts-jest": {
            "tsConfigFile": "tsconfig.jest.json"
          }
        }
      }


// tsconfig.jest.json
{
  "extends": "./tsconfig",
  "compilerOptions": {
    "module": "commonjs"
  }
}

Answer 1

浏览一下，这里的设置与我的设置没有太大不同：

https://github.com/jasonraimondi/typescript-react-starter

在您的jest配置中有一些细微的差异。下面是我的jest.config.js文件的内容。

module.exports = {
  "transform": {
    "^.+\\.tsx?$": "ts-jest"
  },
  "testRegex": "(/__tests__/.*|(\\.|/)(test|spec))\\.(jsx?|tsx?)$",
  "moduleFileExtensions": [
    "ts",
    "tsx",
    "js",
    "jsx",
    "json",
    "node"
  ],
  "setupFiles": [
    "<rootDir>/test/setupTests.ts"
  ]
};

我有一篇关于testing a Typescript React App using ts-jest without "create-react-app"的文章，希望能对你有所帮助。

Answer 2

以下是在TypeScript React项目中使用Jest的示例设置。我自己创建的，我希望它能帮助你：

jest.config.js

const {defaults} = require('jest-config');

module.exports = {
  bail: true,
  moduleFileExtensions: [...defaults.moduleFileExtensions, 'ts', 'tsx'],
  roots: ['src'],
  testMatch: ['<rootDir>/src/**/?(*.)test.{ts,tsx}'],
  transform: {
    '^.+\\.tsx?$': 'ts-jest',
  },
  verbose: true,
};

package.json

{
  "dependencies": {
    "@types/react": "16.7.18",
    "@types/react-dom": "16.0.11",
    "react": "16.7.0",
    "react-dom": "16.7.0"
  },
  "devDependencies": {
    "jest": "23.6.0",
    "ts-jest": "23.10.5"
  },
  "scripts": {
    "test": "jest"
  },
  "version": "0.0.0"
}

src/Welcome.tsx

import * as React from 'react';

interface WelcomeProps {
  name: string,
}

const Welcome: React.FunctionComponent<WelcomeProps> = (props: WelcomeProps) => {
  return <h1>Hello, {props.name}</h1>;
};

export default Welcome;

src/Welcome.test.tsx

import React from 'react';
import ReactDOM from 'react-dom';

import Welcome from './Welcome';

it('renders without crashing', () => {
  const div = document.createElement('div');
  ReactDOM.render(<Welcome name="John Doe"/>, div);
  ReactDOM.unmountComponentAtNode(div);
});

Answer 3

这是唯一对我有效的配置。以下是我的规格：

{
  "name": "project",
  "version": "1.0.0",
  "description": "project",
  "jest": {
    "modulePathIgnorePatterns": [
      "dist/"
    ],
    "snapshotSerializers": [
      "enzyme-to-json/serializer"
    ],
    "moduleNameMapper": {
      "^.+\\.(css|less|scss)$": "identity-obj-proxy"
    },
    "setupFilesAfterEnv": [
      "./setupTests.ts"
    ],
    "coverageReporters": [
      "text",
      "lcov"
    ],
    "coverageDirectory": ".",
    "transform": {
      ".(js|jsx)": "babel-jest",
      ".(ts|tsx)": "ts-jest"
    }
  },
  "peerDependencies": {
    "react": "^16.12.0",
    "react-dom": "^16.12.0"
  },
  "devDependencies": {
    "@types/enzyme": "^3.10.5",
    "@types/enzyme-adapter-react-16": "^1.0.6",
    "@types/jest": "^26.0.4",
    "babel-preset-env": "^1.7.0",
    "babel-preset-react": "^6.24.1",
    "enzyme-adapter-react-16": "^1.12.1",
    "ts-jest": "^26.1.0",
    "typescript": "~3.9.5"
  },
  "scripts": {
    "tsc": "tsc --build tsconfig.json",
    "watch": "tsc --watch",
    "test": "jest",
    "test-coverage": "jest --coverage"
  }
}

setupTests.ts：

import * as Enzyme from 'enzyme';
import * as Adapter from 'enzyme-adapter-react-16';

Enzyme.configure({ adapter: new Adapter() });

最后是我的tsconfig.json：

{
  "compileOnSave": false,
  "compilerOptions": {
    "allowJs": true,
    "declaration": true,
    "declarationMap": true,
    "jsx": "react",
    "emitDecoratorMetadata": true,
    "experimentalDecorators": true,
    "skipLibCheck": true,
    "noImplicitAny": true,
    "target": "es5",
    "outDir": "./dist",
    "declarationDir": "./dist",
    "lib": ["es2016", "dom"]
  },
  "include": ["./src/index.ts"]
}