Remove BakedFile#mime_type

[straight-shoota]

BakedFile doesn't need property mime_type. The mime type of each file can be queried at runtime. In fact, storing the mime type at compile time could lead to some unexpected behaviour when the mime type registry of the build system differs from the execution environment. I can't see any valid use case for having this property.

[lipanski]

I'm bundling assets inside a web app binary - it helps with setting the Content-Type header.

[straight-shoota]

You can get the same values (or even more accurate ones) at runtime. There's no need to have this in the baked file. Regular File instances don't have expose any accessor for retrieving a mime type either.

Take a look at the current code to see how you can implement it in user code:

baked_file_system/src/loader/loader.cr

Line 30 in a23e823

io << " mime_type: " << (mime_type(path) || `file -b --mime-type #{path}`.strip).dump << ",\n"

[rwojsznis]

Hello @straight-shoota - and what about adding mtime instead? I'm trying to implement sane Etag headers support for serving baked files from Kemal and I was about to prepare PR that adds this handy property, but maybe there is a better way? 🤔

update: ok I guess I can just calculate base64digest from the file content itself and just roll with that, should do the job I suppose /shrug

[straight-shoota]

Yeah, I have already suggested that in #16:

In theory, File and BakedFile should be pretty much interchangeable so that applications can easily switch (or combine) loading files from real and virtual file systems. [...]

We could discuss adding for example modification or creation date and hopefully find a way to make this accessible in a way similar to File. A modification date would probably help setting up a custom etag generator.

But that's not related to this issue.

[straight-shoota]

About the issue with mime types: I have a PR pending to add a MIME registry to the crystal (crystal-lang/crystal#5765). When this gets merged and released we can remove BakedFile#mime_type as it can easily be replaced with MIME.fetch.