End-to-End Testing with Protractor – Angular

What You’ll Learn 📚

• Core concepts of end-to-end testing
• How Protractor works with Angular
• Step-by-step examples from simple to complex
• Common questions and troubleshooting tips

Introduction to End-to-End Testing

End-to-end (E2E) testing is like taking your application for a test drive 🚗. It ensures that all parts of your application work together as expected. Think of it as a final check before you hit the road!

E2E tests simulate real user scenarios, making sure everything from the frontend to the backend is functioning smoothly.

Why Use Protractor?

Protractor is specifically designed for Angular applications, making it a perfect fit for testing Angular apps. It understands Angular-specific elements, which means less hassle for you!

Protractor is built on top of WebDriverJS, which is part of the Selenium project.

Key Terminology

• Protractor: A testing framework for Angular and AngularJS applications.
• WebDriver: A tool for automating web application testing.
• Specs: Test files where you define your test cases.

Getting Started with Protractor

Setup Instructions

Before we start, let’s set up our environment. Don’t worry, it’s easier than you think! 😊

1. Install Node.js and npm if you haven’t already. You can download them from nodejs.org.
2. Install Protractor globally by running:

npm install -g protractor

Now, let’s update the WebDriver Manager:

webdriver-manager update

This command downloads the necessary binaries for running tests.

Simple Example: Hello Protractor!

Let’s write our first test. We’ll create a simple Angular app and write a test to check if the title is correct.

// spec.js - our first test file
describe('angularjs homepage', function() {
  it('should have a title', function() {
    browser.get('https://angularjs.org');
    expect(browser.getTitle()).toEqual('AngularJS — Superheroic JavaScript MVW Framework');
  });
});

Running Your Test

To run your test, use the following command:

protractor conf.js

Progressively Complex Examples

Example 1: Interacting with Elements

Let’s add some interaction! We’ll test a simple form submission.

// spec.js
describe('angularjs homepage todo list', function() {
  it('should add a todo', function() {
    browser.get('https://angularjs.org');
    element(by.model('todoList.todoText')).sendKeys('write first protractor test');
    element(by.css('[value="add"]')).click();
    var todoList = element.all(by.repeater('todo in todoList.todos'));
    expect(todoList.count()).toEqual(3);
    expect(todoList.get(2).getText()).toEqual('write first protractor test');
  });
});

Example 2: Handling Asynchronous Operations

Protractor handles asynchronous operations gracefully. Let’s see how:

// spec.js
describe('angularjs homepage', function() {
  it('should wait for the element to be visible', function() {
    browser.get('https://angularjs.org');
    var EC = protractor.ExpectedConditions;
    var button = element(by.css('[value="add"]'));
    browser.wait(EC.visibilityOf(button), 5000);
    button.click();
  });
});

Example 3: Testing with Multiple Browsers

Protractor can run tests in different browsers. Here’s how to configure it:

// conf.js
exports.config = {
  multiCapabilities: [{
    'browserName': 'firefox'
  }, {
    'browserName': 'chrome'
  }]
};

Common Questions and Answers

1. What is Protractor?

   Protractor is an end-to-end test framework for Angular applications, built on top of WebDriverJS.

2. Why use Protractor over other testing tools?

   Protractor is tailored for Angular, making it easier to handle Angular-specific elements and asynchronous operations.

3. How do I install Protractor?

   Use npm to install Protractor globally with npm install -g protractor.

4. What is a spec file?

   A spec file contains your test cases, written in Jasmine syntax.

5. How do I run Protractor tests?

   Use the command protractor conf.js to run your tests.

6. What is WebDriver Manager?

   WebDriver Manager helps manage browser drivers needed for running tests.

7. Can Protractor test non-Angular applications?

   Yes, but it’s optimized for Angular. For non-Angular apps, consider using Selenium directly.

8. How do I handle asynchronous operations?

   Protractor automatically waits for Angular, but you can use browser.wait() for non-Angular elements.

9. What are Expected Conditions?

   Expected Conditions are used to wait for certain conditions to be met before proceeding with a test.

10. How do I test in multiple browsers?

    Use the multiCapabilities option in your configuration file.

11. What is Jasmine?

    Jasmine is a behavior-driven development framework for testing JavaScript code.

12. How do I debug Protractor tests?

    Use browser.pause() to pause tests and inspect the browser state.

13. Why are my tests failing?

    Check for asynchronous issues, incorrect selectors, or configuration errors.

14. How do I update WebDriver?

    Run webdriver-manager update to download the latest binaries.

15. Can I use Protractor with TypeScript?

    Yes, Protractor supports TypeScript. You’ll need to set up a TypeScript configuration file.

16. What is the role of the configuration file?

    The configuration file sets up the test environment, including browser settings and test specs.

17. How do I handle alerts and pop-ups?

    Use Protractor’s alert handling functions like browser.switchTo().alert().

18. How do I take screenshots on test failure?

    Use Protractor’s afterEach function to capture screenshots when tests fail.

19. What is the difference between unit and E2E testing?

    Unit tests check individual components, while E2E tests check the entire application flow.

20. How do I write maintainable tests?

    Use page objects to separate test logic from page details, making tests easier to maintain.

Troubleshooting Common Issues

Issue: Tests Failing Due to Timeouts

Solution: Increase the default timeout in your configuration file or use browser.wait() for specific elements.

Issue: Element Not Found

Solution: Double-check your selectors and ensure elements are available before interacting with them.

Issue: Browser Not Launching

Solution: Ensure WebDriver Manager is updated and the correct browser drivers are installed.

Issue: Angular Not Detected

Solution: Use browser.waitForAngularEnabled(false) for non-Angular pages.

Practice Exercises

1. Create a new Angular app and write a Protractor test to check if a button click changes the text on the page.
2. Modify the todo list example to delete an item and verify it’s removed.
3. Write a test that checks if a form submission displays a success message.

Remember, practice makes perfect! Keep experimenting and testing different scenarios. You’ve got this! 💪

Additional Resources

• Protractor Official Documentation
• Angular Testing Guide
• Jasmine Documentation