Types of Tests

In this lesson we will dive into the different types of tests that developers use. Let’s discuss them one by one:

• Unit tests: check units in isolation. What is considered to be a unit can change in context.

• Component tests: a test of Components of modern JavaScript frameworks.

• Integration tests: check that multiple units behave as expected when used together.

• UI Integration tests: check that the whole application works without a real back-end.

• E2E tests: check the whole app, back-end and database included, works as expected

• Visual Regression tests: check that the app look doesn’t change when not intended

Comparison of different tests

✅= Yes

❌= No

⚠️ =Somewhere between Yes and No

	E2E	UI Integration	Visual	Integration	Component/Unit
check the entire app	✅	❌	❌	❌	❌
give a good confidenceThis refers to the confidence that your application works because the tests pass. Confidence is limited for Unit tests and high for E2E tests	✅	✅	✅	⚠️	❌
have code coverage	✅	✅	❌	✅	✅
have a good cost/speed ratio	❌	✅	❌	✅	✅
are deterministic	❌	✅	❌	✅	✅
are simple	❌	⚠️	✅	⚠️	✅
are short	❌	❌	✅	✅	✅