End-to-end (E2E) testing is a crucial part of the software development lifecycle, ensuring that the entire application flow works as expected. In Angular, E2E testing is typically performed using tools like Protractor or Cypress. This section will guide you through the basics of setting up and writing E2E tests for your Angular applications.

End-to-end testing involves testing the complete application from start to finish to ensure that all integrated components work together as expected. It simulates real user scenarios and interactions to validate the application's functionality, performance, and reliability.

• User Scenarios: Simulating real user interactions with the application.
• Integration Testing: Ensuring that different parts of the application work together.
• Automation: Using tools to automate the testing process.

Protractor is an end-to-end test framework for Angular and AngularJS applications. It runs tests against your application running in a real browser, interacting with it as a user would.

1. Install Protractor:

   npm install -g protractor
   

2. Update WebDriver Manager:

   webdriver-manager update
   

3. Create a Protractor Configuration File: Create a file named protractor.conf.js in your project root:

   exports.config = {
     framework: 'jasmine',
     seleniumAddress: 'http://localhost:4444/wd/hub',
     specs: ['e2e/**/*.e2e-spec.js'],
     capabilities: {
       browserName: 'chrome'
     }
   };
   

4. Start WebDriver Manager:

   webdriver-manager start
   

5. Run Protractor Tests:

   protractor protractor.conf.js
   

E2E tests in Protractor are written using Jasmine, a behavior-driven development framework for testing JavaScript code.

1. Create a Test File: Create a file named app.e2e-spec.js in the e2e folder:

   describe('Angular App', () => {
     it('should have a title', () => {
       browser.get('http://localhost:4200');
       expect(browser.getTitle()).toEqual('My Angular App');
     });
   });
   

2. Explanation:

   • describe: Defines a test suite.
   • it: Defines a test case.
   • browser.get: Navigates to the specified URL.
   • expect: Asserts that the application title is as expected.

Let's write a more comprehensive test that interacts with a form on the application.

1. Test File:

   describe('Form Interaction', () => {
     beforeEach(() => {
       browser.get('http://localhost:4200/form');
     });
   
     it('should submit the form successfully', () => {
       element(by.css('input[name="username"]')).sendKeys('testuser');
       element(by.css('input[name="password"]')).sendKeys('password123');
       element(by.css('button[type="submit"]')).click();
   
       const successMessage = element(by.css('.success-message'));
       expect(successMessage.getText()).toEqual('Form submitted successfully!');
     });
   });
   

2. Explanation:

   • beforeEach: Runs before each test case, navigating to the form page.
   • element(by.css(...)): Selects elements using CSS selectors.
   • sendKeys: Simulates typing into an input field.
   • click: Simulates a click event.
   • getText: Retrieves the text content of an element.

• Not Waiting for Elements: Ensure elements are present before interacting with them.
• Hardcoding URLs: Use relative URLs or environment variables.
• Ignoring Browser Compatibility: Test across different browsers.

• Use browser.wait: Wait for elements to be present or conditions to be met.
• Modularize Tests: Break tests into smaller, reusable functions.
• Use Page Objects: Encapsulate page-specific logic in separate classes.

1. Create a New E2E Test:

   • Navigate to a login page.
   • Enter a username and password.
   • Click the login button.
   • Verify that the user is redirected to the dashboard.

2. Solution:

   describe('Login Flow', () => {
     beforeEach(() => {
       browser.get('http://localhost:4200/login');
     });
   
     it('should login and redirect to dashboard', () => {
       element(by.css('input[name="username"]')).sendKeys('testuser');
       element(by.css('input[name="password"]')).sendKeys('password123');
       element(by.css('button[type="submit"]')).click();
   
       browser.wait(protractor.ExpectedConditions.urlContains('/dashboard'), 5000);
       expect(browser.getCurrentUrl()).toContain('/dashboard');
     });
   });
   

End-to-end testing is essential for ensuring the reliability and functionality of your Angular applications. By simulating real user interactions, you can catch issues that might not be apparent through unit or integration tests. Protractor provides a robust framework for writing and running these tests, helping you maintain high-quality applications. In the next module, we will delve into advanced Angular concepts to further enhance your development skills.