TTD
- How to test tests: make it fail
- How to write good code: pair programming, code review
In TDD, we should create tests first. The tests drive the development, and goes in a cycle (commonly called Red, Green, Refactor). You can also add a commit at the end of one cycle to ensure that you can revert your changes in case you break your code during a new cycle and do not know how to fix it.
AAA
To help with remembering how to write tests:
Arrange > Act > Assert
Libraries to install
React-testing-library + Jest + Jest-dom
React-testing-library provides the library for testing React apps, and Jest is a JS testing framework. You can use other testing frameworks as well.
jest-dom library provides a set of custom jest matchers to assert stuff on the state of dom that you can use to extend jest
eg:
and use it, otherwise, your tests might be affected because trash values are still around
jest “filename”
jest [search by pattern]
(ie: don’t test integration/ e2e)
Testing:
use querySelectorAll or querySelector before testid
(Priority: https://testing-library.com/docs/guide-which-query#docsNav)
getByTestId: The user cannot see (or hear) these, so this is only recommended for cases where you can’t match by text or it doesn’t make sense (the text is dynamic).
- bootstrap uses jquery for dom manipulation so there might be conflicts in react
(bootstrap5 is gonna drop jquery)
- queryByText returns null instead of an error
- getByText returns error if not found
Stuff I Have Learnt 