Cypress with TypeScript: A Comprehensive Guide with GitHub Examples

Table of Contents

1. Fundamental Concepts
2. Setting up a Cypress TypeScript Project
3. Using Cypress with TypeScript on GitHub
4. Common Practices
5. Best Practices
6. Conclusion
7. References

1. Fundamental Concepts

Cypress

Cypress is a JavaScript end - to - end testing framework designed specifically for web applications. It runs directly in the browser, allowing for real - time feedback and easy debugging. Cypress can interact with the DOM, simulate user actions like clicks and inputs, and make assertions about the application’s state.

TypeScript

TypeScript is a superset of JavaScript that adds static typing to the language. By using TypeScript with Cypress, developers can catch type - related errors at compile - time, write more maintainable code, and take advantage of modern JavaScript features.

GitHub

GitHub is a web - based platform for version control using Git. It allows developers to share their code, collaborate with others, and discover open - source projects. Many developers share their Cypress TypeScript projects on GitHub, which can be used as a reference for learning and inspiration.

2. Setting up a Cypress TypeScript Project

Step 1: Create a new project directory

mkdir cypress-typescript-example
cd cypress-typescript-example

Step 2: Initialize a new npm project

npm init -y

Step 3: Install Cypress and TypeScript

npm install cypress typescript --save - dev

Step 4: Configure TypeScript

Create a tsconfig.json file in the root directory with the following content:

{
  "compilerOptions": {
    "target": "ES6",
    "module": "commonjs",
    "lib": ["es6", "dom"],
    "outDir": "./dist",
    "rootDir": "./cypress",
    "strict": true,
    "esModuleInterop": true,
    "skipLibCheck": true,
    "forceConsistentCasingInFileNames": true
  },
  "include": ["cypress/**/*.ts"]
}

Step 5: Configure Cypress to use TypeScript

Create a cypress.json file in the root directory:

{
  "testFiles": "**/*.spec.ts"
}

Step 6: Write a simple test

Create a test file cypress/integration/example.spec.ts:

describe('My First Test', () => {
  it('Visits the Kitchen Sink', () => {
    cy.visit('https://example.cypress.io')
    cy.contains('type').click()
    cy.url().should('include', '/commands/actions')
  })
})

Step 7: Run the tests

npx cypress open

3. Using Cypress with TypeScript on GitHub

Finding Examples

You can search for Cypress TypeScript projects on GitHub using keywords like “cypress typescript example”. For example, you can visit the official Cypress repository on GitHub (https://github.com/cypress - io/cypress) and look for examples in the examples directory.

Cloning and Running a Project

To clone a Cypress TypeScript project from GitHub, follow these steps:

git clone <repository - url>
cd <repository - name>
npm install
npx cypress open

4. Common Practices

Test Structure

Organize your tests into logical groups using describe blocks. Each describe block can represent a feature or a page of your application. For example:

describe('Login Page', () => {
  beforeEach(() => {
    cy.visit('/login')
  })

  it('Should display the login form', () => {
    cy.get('form').should('be.visible')
  })

  it('Should show an error message for invalid credentials', () => {
    cy.get('input[name="username"]').type('invaliduser')
    cy.get('input[name="password"]').type('invalidpass')
    cy.get('button[type="submit"]').click()
    cy.get('.error - message').should('be.visible')
  })
})

Using Custom Commands

Cypress allows you to create custom commands to simplify your tests. In cypress/support/commands.ts, you can define custom commands:

Cypress.Commands.add('login', (username: string, password: string) => {
  cy.get('input[name="username"]').type(username)
  cy.get('input[name="password"]').type(password)
  cy.get('button[type="submit"]').click()
})

Then, you can use the custom command in your tests:

describe('Dashboard', () => {
  it('Should show the dashboard after login', () => {
    cy.login('validuser', 'validpass')
    cy.get('.dashboard').should('be.visible')
  })
})

5. Best Practices

Keep Tests Independent

Each test should be independent of others. This means that the outcome of one test should not affect the outcome of another. Use the beforeEach and afterEach hooks to set up and tear down the test environment.

Use Explicit Assertions

Instead of relying on implicit assertions, use explicit assertions to make your tests more readable and reliable. For example, use cy.get('element').should('have.text', 'expected text') instead of just cy.get('element').contains('expected text') in some cases.

Version Control and Continuous Integration

Use GitHub for version control and set up a continuous integration (CI) pipeline using tools like GitHub Actions. This ensures that your tests are run automatically whenever there are changes to the codebase.

6. Conclusion

Combining Cypress with TypeScript provides a powerful and efficient way to write end - to - end tests for web applications. GitHub serves as a valuable resource for finding and sharing Cypress TypeScript examples. By following the fundamental concepts, usage methods, common practices, and best practices outlined in this blog, developers can write high - quality tests that are easy to maintain and scale.

7. References

• Cypress official documentation: https://docs.cypress.io/
• TypeScript official documentation: https://www.typescriptlang.org/docs/
• GitHub official documentation: https://docs.github.com/

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