Checks each key/value inside the web manifest file to make sure they are formatted correctly.
A web manifest file is a JSON file that can be used by web browser to discover certain information about the website. It is useful for making Progressive Web Apps that can be installed on the homepage of a user's mobile device, as well as for other purposes. A proper web manifest file allows users to create shortcuts to the website which have an optimized name and icon.
This test downloads the manifest file and checks each key and value to make sure they are formatted correctly and have no errors. Any errors that are discovered will be reported as part of the test.
For more information, please read the documentation on MDN Web Docs.