Extracting a form-finder method

We'll be writing quite a few tests for this form, so let's extract the call to querySelector into an arrow function. Add this just below the beforeEach definition:

const form = id => container.querySelector(`form[id="${id}"]`);

The expectation in your test then becomes this:

expect(form('customer')).not.toBeNull();

This is much more readable, because the CSS selector is abstracted away behind the function call. I'd encourage you to repeat that pattern in your tests. CSS selectors are a useful tool, but they detract from the "plain English" that you should be aiming for in your tests.