Writing Cypress Tests with TypeScript

Cypress can be used to write tests in TypeScript, a typed superset of JavaScript. To use TypeScript with Cypress, you'll need to set up a TypeScript development environment and configure Cypress to use TypeScript.

Here is an example of how you can set up a TypeScript development environment for Cypress:

1. Install Cypress and TypeScript as devDependencies:

npm install -D cypress typescript

2. Create a TypeScript configuration file tsconfig.json:

{
  "compilerOptions": {
    "target": "es5",
    "module": "commonjs",
    "lib": ["dom", "es6"],
    "types": ["cypress"]
  },
  "include": ["cypress/**/*.ts"]
}

3. Create a cypress/plugins/index.js file and add the following code:

const tsPreprocessor = require('ts-loader');
module.exports = (on) => {
  on('file:preprocessor', tsPreprocessor);
};

This will configure Cypress to use TypeScript as the preprocessor.

4. Create a TypeScript test file cypress/integration/my-test.ts:

describe('My Test', () => {
  it('Visits the app root url', () => {
    cy.visit('http://localhost:3000');
    cy.contains('h1', 'Welcome to My App');
  });
});

5. To run the test you can use the command npx cypress run