Add configurable fileTypes for upload and HTTP serving

[bollwyvl]

References

• fixes More configurable mime types for serving, contents #667
• partially includes
  • Update serve.py #570
  • Add configurable (extra)FileTypes #668
  • Implement a custom Emscripten File System which communicates with the JupyterLab Content Manager, giving file access to pyolite #655

Code changes

• adds fileTypes, using a subset of the IRenderMime.IFileType to jupyter-lite.json
• adds to jupyter_lite_config.json as (extra_)file_types which get merged together
• removes most hard-coded mimetypes from client-side contents manager
• uses configured mime types in server as well
• defaults uploaded files to file/base64 instead of json/notebook

User-facing changes

• a larger collection of uploaded files will work out-of-the-box
• site owners can customize (or entirely replace) these

Backwards-incompatible changes

• a number of constants are no longer hoisted

[github-actions]

👈 Try it on ReadTheDocs

[jtpio]

The docs failed to build on the latest main, which looks related to the new release of myst-nb on conda mreged yesterday: conda-forge/myst-nb-feedstock#18

5d6e522 seems to be fixing it.

[bollwyvl]

Thanks for the assist. When last I put it down, most of the arbitrary file types i tried were working for various upload/download scenarios. PDF was still bothersome.

[jtpio]

Yes I gave it a spin on RTD and it looked good. Let's get it in.

[bollwyvl]

.... i found one more thing with SVG... taking a look.

[jtpio]

a larger collection of uploaded files will work out-of-the-box

This fixes the fasta example which was failing to open until now:

[bollwyvl]

fixes the fasta example

right, but the more telling thing is:

• download the fasta
• re-upload the fasta

I was specifically seeing SVG come out as json, as its Untitled file was starting life as a notebook. I hope to test this out once more, but am pretty slammed these days and might not be able to fix anything i find.

Hate to hold things up, but getting reports like this doesn't work for my niche file format are really boring when the feature is otherwise awesome, and we have a plan for letting owners fix arbitrary formats.

[bollwyvl]

i also haven't tested any of the #655 stuff vs the webrtc backend. if it breaks that, we need to stop and re-think whether we need to be able to put all of the serviceworker stuff behind a build flag.

[bollwyvl]

hm... looks like this is breaking config somehow, e.g. not propagating collaborative...

[jtpio]

vs the webrtc backend. if it breaks that, we need to stop and re-think whether we need to be able to put all of the serviceworker stuff behind a build flag.

I tried with the RTD preview for this PR, and editing seems to be working as before:

New files and directories created from the kernel are not replicated across peers, but that was also the case before when creating new files from the UI.

Although it's not clear yet how this will work, there will likely be substantial changes needed when updating to JupyterLab 4.0 packages with the RTC logic progressively moving to the server.

[bollwyvl]

files and directories created from the kernel are not replicated across peers

i tried this out too... it looks like they will work, once you open them in both browsers, and somebody decides to accept the Revert option. That's good enough for me!

No further changes planned (other than cleaning up the title of the PR).

[martinRenou]

LGTM! Thanks for doing this

[jtpio]

Thanks!