Setting up Cypress with a React.js and TypeScript

Introduction:

Testing React.js applications ensures code reliability and quality. In this tutorial, we’ll delve into integrating Cypress for testing React.js projects with TypeScript.

Why Cypress?

Cypress offers an intuitive testing experience, enabling end-to-end testing with real-time feedback. Its seamless integration with React.js and TypeScript makes it an ideal choice for modern web applications.

Prerequisites:

Ensure you have Node.js and npm installed, along with a React.js project configured with TypeScript.

Initialize Your React.js TypeScript Project:

• If you haven’t already, create a new React.js project with TypeScript. You can do this using Create React App with TypeScript template:

npx create-react-app my-app --template typescript

• Install Cypress:
  • Navigate to your project directory and install Cypress as a dev dependency:cssCopy code

npm install --save-dev cypress

• Initialize Cypress:
  • After installing Cypress, initialize it in your project directory:

npx cypress open

• This will create a cypress directory with default configuration and examples.

Configure TypeScript Support for Cypress:

• Cypress doesn’t natively support TypeScript, so you’ll need to add support manually.
• Install TypeScript and related dependencies:scss

npm install --save-dev typescript @cypress/webpack-preprocessor @types/react @types/react-dom

• Create a tsconfig.json file in your project root with TypeScript configurations. You can start with a basic setup:

{
  "compilerOptions": {
    "target": "es5",
    "lib": ["dom", "dom.iterable", "esnext"],
    "allowJs": true,
    "skipLibCheck": true,
    "esModuleInterop": true,
    "allowSyntheticDefaultImports": true,
    "strict": true,
    "forceConsistentCasingInFileNames": true,
    "module": "esnext",
    "moduleResolution": "node",
    "resolveJsonModule": true,
    "isolatedModules": true,
    "noEmit": true,
    "jsx": "react",
    "types": ["cypress"]
  },
  "include": ["cypress/**/*.ts"]
}

Update the cypress/plugins/index.js file to add TypeScript support:

const wp = require('@cypress/webpack-preprocessor');

module.exports = (on, config) => {
  const options = {
    webpackOptions: require('../webpack.config'),
  };
  on('file:preprocessor', wp(options));
};

• Create a webpack.config.js file in your project root to define webpack configuration:

module.exports = {
  resolve: {
    extensions: ['.ts', '.js'],
  },
  module: {
    rules: [
      {
        test: /\.tsx?$/,
        loader: 'ts-loader',
        options: { configFile: 'tsconfig.json' },
        exclude: [/node_modules/],
      },
    ],
  },
};

Write Cypress Tests:

• Now you can write your Cypress tests in TypeScript. Place your test files in the cypress/integration directory.

Run Cypress Tests:

• You can run your Cypress tests with the Cypress Test Runner:

npx cypress open

• Or, you can run tests headlessly using the Cypress CLI:

npx cypress run