[web] Register application/wasm MIME type

[lukewagner]

We should follow the procedure to register 'application/wasm' as an official MIME type.

(Incidentally, lack of official registration blocks WebAssembly.compileStreaming from consuming .wasm files served by GH Pages.)

[dschuff]

I believe @flagxor actually just started this process.

[lukewagner]

Nice! Maybe he can just close this issue once it's done?

[littledan]

Should we register a mimetype for Wasm text format?

[jfbastien]

We don't expect browsers to consume the text format except to display it as-is, no?

[littledan]

I didn't mean for it to be interpreted by browsers. Maybe it doesn't make sense. Mimetypes aren't just for browsers, but they're also not for entirely arbitrary things with a file extension. I was just thinking about the appropriate way to note the extension in the standards universe. (There was a recent update to the JavaScript mimetype to support .mjs, FWIW.)

[jfbastien]

IIUC .mjs changes how you parse the file (because modules don't parse the same as .js), whereas for the WebAssembly text format it seems like text/plain is what's needed?

[littledan]

This is a tangent, but .mjs doesn't change anything for browsers and doesn't have its own mimetype; it's just included in the JS mimetype.

[lukewagner]

As an update, .wasm is now a registered extension in mime-db which is the database used by GitHub Pages. Here's a test I just made which shows the change is live. Even better, .wasm files are marked as compressible so they are served with gzip compression.

[ericprud]

This should be handled by W3C-IETF registration process