Testing is an important part of the development process and many organizations practice a standard of development known as "test-driven development". This is when developers write tests first, before they ever start developing their application. All the tests initially fail and then they start writing application code to make these tests pass.

Whether you work in an organization that uses test-driven development or in an organization that uses tests to make sure future feature development doesn't break existing features, it's an important skill to have!

-- Test allFeeds to make sure it is defined and it's length not 0.

-- Feed Url to make sure it is defined and it's length not undefined.

-- Name property of allFeeds array, test it to make sure it is defined and not be empty string.

-- Test menu to make sure it is hidden on document load and has CSS class menu-hidden.

-- Spy on menu click event to make sure it has been triggerd and toggling css class menu-hidden functionality works fine when triggerd and when triggerd again to close the menu.

-- Test the asynchronous function loadFeed to make sure it is success to get the data from the server and test it again to make sure the data has been binded successfully.

Just run npm install so that install all dependances.

You can host the app on a remote server or run it locally on your local host server. I recommeded to use vs code, so you can use live server plugin to run the app on your local host.