Testing Javascript: Building JavaScript applications you won't hate

on YouTube ↗21m

" summary

Concrete takeaways: use static analysis (ESLint, TypeScript) to catch errors cheaply, write fast unit tests with Jest and isolate rendering from state, prefer Redux-like stores to reduce component interaction tests, use snapshots sparingly, run mutation testing with Stryker locally to find weak tests, and reserve Cypress end-to-end tests for a few core workflows. 100% snapshot coverage is deceptive and run mutation tests locally not in CI — contract testing (Pact-like) protects front end/back end contracts.

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" chapters (16)

1. 0:00Intro
2. 0:31TESTING JAVASCRIPT BUILDING JAVASCRIPT APPLICATIONS YOU WON'T HATE
3. 1:53WHY DO WE TEST?
4. 2:12REFACTORING
5. 3:29WHAT DO WE TEST?
6. 4:19INTEGRATION TESTS ARE A SCAM
7. 4:48TESTING TOOLKIT
8. 5:10STATIC ANALYSIS ESLINT & TYPESCRIPT
9. 6:20TESTS ARE EXAMPLES CORRECTNESS IS HARD TO PROVE FROM EXAMPLES
10. 6:37TYPES DEFINE CATEGORIES CATEGORIES CANNOT PROVE CORRECTNESS
11. 7:20UNIT TESTING JEST
12. 8:03INTEGRATION TESTING JEST
13. 8:21VUEX / REDUX
14. 12:09MUTATION TESTING STRYKER
15. 14:58E2E TESTING WITH CYPRESS.IO
16. 16:35CONTRACT TESTING PACTIO

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