React Testing Strategy: What to Test and Why Course

Learn what to test, what to skip, and how to keep tests maintainable. This course focuses more on how to know what to test.

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You can already write a test (if not: check the other courses on this site such as this course on React Frontend Testing). The harder thing to learn is is picking which tests to write and knowing why you want to test them.

If you chose badly, you end up with slow tests testing the wrong thing and giving you no value and no confidence your application is working as you expect.

This course goes over the theoretical questions of picking what to test and how to pick a good strategy so your tests are giving you the most value.

It's a mindset course, not a coding one, so there's nothing to type here. Read the lessons and you should be able to articulate well and understand when to pick what tests to write and which to skip writing.

Course Lessons

10 lessons to learn everything about React Testing Strategy: What to Test and Why

Testing Fundamentals

Why Bother Writing Tests?

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Understand why writing and running tests is so important, and why tests should be as good quality as your production code

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Unit vs Integration vs E2E: The Argument That Never Ends

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Understand the importance of the different types of test, and how to know when to test your apps with each of these

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Your Tests Shouldn't Know How Your Code Works - testing behaviour not implementations

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Why you should test behaviour and outcomes, not internal implementation details.

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What to Test

Not Everything Deserves a Test. Here's How to Choose

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100% Coverage Is a Trap - not everything needs a test. In this lesson we will cover how to pick what parts of your app needs tests, and which parts or flows can be skipped

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Testing Logic and Pure Functions

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How to test things like business logic and other non React specific functionality

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How to write good integration tests so you know everything will work when wired together

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Testing how pieces talk to each other, and how to split up testing larger widgets/apps

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Common Pitfalls

Brittle Tests - How to avoid them by thinking about your tests before you write them

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How to avoid brittle tests - those tests that you end up spending more time maintaining and constantly fixing than the value they give

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What are flaky tests and approaches to avoid having them in your test suite

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How to avoid flaky tests - no one likes having to re-run the same tests because some badly written test is flaky and sometimes randomly fails. In this lesson we cover how to avoid writing them in the first place

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Why assertions that pass don't always mean your app works (false positives & false negativesin tests)

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How to avoid your tests passing when actually the unit it is testing is broken - and why this is so important

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Code Smells, but for Your Tests - Testing Mistakes Everyone Makes

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Over-testing, over-mocking, testing implementation, and the rest. Here are the main anti patterns and code smells when it comes to frontend testing.

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