Modern JavaScript from the Beginning - Second Edition - Has Duplicate IDs - jsdom

The video tutorial explains how to create a JavaScript function to check a DOM tree for duplicate IDs. It covers setting up a test environment, writing initial tests, creating mock elements, implementing the function, and using hooks to optimize the testing process. The tutorial emphasizes the importance of avoiding duplicate IDs in a DOM and demonstrates how to use JavaScript sets to store unique values. It also highlights the use of beforeEach and afterEach hooks to make the code DRY and efficient.

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