React beginners often confuse the tools for testing in React. React Testing Library is not an alternative to Jest, because they need each other and every one of them has a clear task.
If you are using create-react-app, Jest (and React Testing Library) comes by default with the installation. Let‘s look at the following functions for your tests:
describe(‘my function or component‘, () => {
test(‘does the following‘, () => {
expect(2 + 4).toBe(6);
});
});
Whereas the describe-block is the test suite
the test-block (which also can be named it
instead of test
) is the test case. A test suite can have multiple test cases and a test case doesn‘t have to be in a test suite.
What you put into the test cases are called assertions (e.g. expect
in Jest) which either turn out to be successful (green) or erroneous (red).
原文:https://www.cnblogs.com/testopsfeng/p/14265218.html