Add .cjs to mimetypes

[johnfraney]

Feature or enhancement

Proposal:

.cjs is a JavaScript extension for CommonJS modules and is used pretty commonly (ha) by JS like Vite. It's also a format that NodeJS supports.

It could be good to add it to mimetypes since it is a widely-used extension.

Has this already been discussed elsewhere?

This is a minor feature, which does not need previous discussion elsewhere

Links to previous discussion of this feature:

No response

Linked PRs

• gh-140942: Add MIME type for .cjs extension #140937

[StanFromIreland]

I do not think this change is correct, it is not officially registered with IANA as required, .cjs is not listed as an alias of text/javascript:

File extension(s): .js, .mjs

[ZeroIntensity]

I'm not sure that mimetypes is supposed to be 100% compliant with IANA. For example, we support the .jpe extension for JPEG files, despite that not being specified.

There are also several supported extensions for application/octet-stream, and IANA doesn't specify any file extension for that. That suggests IANA's file extension specification isn't meant to be exhaustive.

[StanFromIreland]

The two cases you mentioned exist in mimetypes since 1997 (ac8a9f3), only in 2006 was the comment requiring they be registered added.

[StanFromIreland]

We can put it in common_types, which allows for non-IANA registered types. Per the documentation:

The optional strict argument is a flag specifying whether the list of known MIME types is limited to only the official types registered with IANA.

[picnixz]

FTR, mimetypes is supposed to be IANA compliant, as per the comment:

# Before adding new types, make sure they are either registered with IANA,
# at https://www.iana.org/assignments/media-types/media-types.xhtml
# or extensions, i.e. using the x- prefix

The reason why .exe & co are mapped to octect-stream is likely for convenience (the IANA type for .exe is https://www.iana.org/assignments/media-types/application/vnd.microsoft.portable-executable) and using octect-stream instead to indicate binary data is probably the best practical choice.

[johnfraney]

We can put it in common_types, which allows for non-IANA registered types. Per the documentation:

Oh! Thank you, @StanFromIreland. I missed that comment. I'll put up a PR with that extension added to common_types instead

[StanFromIreland]

The reason why .exe & co are mapped to octect-stream is likely for convenience (the IANA type for .exe is https://www.iana.org/assignments/media-types/application/vnd.microsoft.portable-executable)

That seems like a bug, the addition of .exe (1997) predates the official registration (2015) of the application/vnd.microsoft.portable-executable mimetype.