Disallow non-standard file extension for the web app manifest file

Disallow non-standard file extension for the web app manifest file (manifest-file-extension)

manifest-file-extension warns against using non-standard file extensions for the web app manifest file.

Why is this important?

While the .webmanifest file extension is not enforced by the specification, nor is it required by browsers, using it makes it:

What does the rule check?

The rule checks if the recommended .webmanifest file extension is used for the web app manifest file.

Examples that trigger the rule

<link rel="manifest" href="site.json">
<link rel="manifest" href="site.manifest">

Examples that pass the rule

<link rel="manifest" href="site.webmanifest">

Further Reading