No matter what tests you implement, sooner or later, you will eventually need "Test Doubles". But what is a "Test Double"? A jargon for saying "Mock" or more than that?
Although attractive, especially in the JS ecosystem, some "Test Doubles" can make our tests more expensive to maintain while harming their readability. They can also over-specify our tests and couple them to implementation details... even worse, they can end up discouraging us from implementing new tests, or even pushing us to get rid of some of them.
Oops. I don't have much room to tell you the rest here, but I'll see you at JS Poland to tell you how "Fakes" and their faithful companions "Object Mothers" and "Gloves" end up becoming the pillars of your testing strategy.
Testing or more specifically, front-end testing is undeniably in the top 3 of the most complex topics associated with Angular & front-end development.
When one is confronted with this complexity, it is tempting to give up, but at what cost? It is totally possible to develop an application without tests but is it really faster? What happens to code maintainability a few months or sometimes just weeks later? Can we serenely refactor and deploy our apps regularly while it is getting older and complex in our hands? What about end-to-end tests, they sound attractive but are they enough?
This workshop presents, through practical exercises, pragmatic Angular testing techniques. You will also learn how to implement simple, meaningful, maintainable, and above all profitable tests.
What attendees will learn
During this workshop, you will learn:
- how to implement tests for your Angular application with the Test-Driven Development approach,
- how to choose the type of tests that fits best depending on the context,
- how to decouple tests from code to encourage refactoring and tidying up when needed,
- how to implement maintainable and human-readable tests,
- the difference between dummies, stubs, spies, mocks, and fakes + how and when to use them,
- the difference between isolated, shallow & integration component testing,
- how to choose the right scope for your tests,
- lots of tips & tricks that will help you adopt a pragmatic testing strategy.
You will learn how to write profitable tests, in other terms, you'll learn how to reduce the cost of writing and maintaining tests while increasing their trustworthiness. This will boost the whole team’s confidence and efficiency. You will be able to choose the right tests to implement and how to implement them. You will also learn how to leverage the benefits of Progressive TDD to change your code with confidence, and you will be able to decouple your tests from the tested code so you change the code structure without having to fix tests all the time.
👨🏻🏫Introduction to testing
- Why test?
- What should we expect from a test?
- The different types of tests: Narrow & Wide vs Unit & Integration.
- Do you need Jest?
- Pros & cons.
💻 Exercise: First Test
- Progressive TDD.
- Making tests readable and maintainable with Object Mothers.
- Tips & Tricks.
- Testing asynchronous code.
💻Exercise: Test Doubles
- Dummies vs Stubs vs Mocks vs Spies vs Fakes: which one should we use?
- Contract testing fakes
- Different types of component tests: Integration vs Shallow vs Isolated.
- Angular Testing Library: Pros & Cons.
- Cypress Component Testing: Pros & Cons.
- Playwright Component Testing: Pros & Cons.
💻Exercise: Testing Components with Playwright Component Testing
- Which Test Doubles should we use?
- Testing Inputs & Outputs based communication.
👨🏻🏫Visual Regression Testing
- Testing the presentation.
- Visual regression testing with Playwright Component Testing
👨🏻🏫Building your Pragmatic Testing Strategy
- What should we test and how?