Questions

Answer the following questions to check what you have learned in this chapter:

1. We have written some tests for a HomePage component and placed them in a file called HomePage.tests.tsx. However, the tests aren’t run when the npm test command is executed—not even when the a key is pressed to run all the tests. What do you think the problem might be?
2. Why doesn’t the following expectation pass? How could this be resolved?

   expect({ name: 'Bob' }).toBe({ name: 'Bob' });

3. Which matcher can be used to check that a variable isn’t null?
4. Here’s an expectation that checks whether a Save button is disabled:

   expect(

     screen.getByText('Save').hasAttribute('disabled')

   ).toBe(true);

The expectation passes as expected, but is there a different matcher that can be used to simplify this?

5. Write a test for the getNewCheckedIds function we used in this chapter. The test should check...