In JupyterLab 2.0: "The extension "jupyterlab-jupytext" is outdated."

[mwouts]

The current version of the JupyterLab-jupytext extension is not compatible with JupyterLab 2.0.
A migration guide is available here.

[jhelie]

Hi Marc, I've got a tentative PR at #449. Curious to know whether it was easy as that (I'm not a JS person). In any case I can confirm it worked on my machine following these changes.

[mwouts]

Hello Jean, thanks for contributing this! Yes indeed, my expectation is that we just need to bump the version of the libraries in the requirement, so I do think that you did it right.

I have very minor comments on your PR, see #449 . But there is also a more important question... when should we ship this new version of the extension? I am afraid that it will be incompatible with JupyterLab 1.x... So, tell me what you think of the following proposal:

• we publish the current version of the extension (1.1.1) on npm
• we package the new version of the extension (1.2, your PR) in the next version of Jupytext (1.3.5 was on the way)
• we document in the CHANGELOG, and in the extension README, the fact that people using JupyterLab 1.x will have to install the version 1.1.1 of the extension manually from npm (we already have a similar comment for people that were using JupyterLab 0.x).

[jhelie]

Hi Marc, thanks for the feedback. This makes a lot of sense to me. Is there an rc branch for 1.3.5 that I should retarget #449 against?

[mwouts]

Jean, I have updated your PR. If it's good for you we could release it in Jupytext 1.4.0 (I finally prefer to increase the minor version number, as we are going to break the compatibility with JupyterLab 1.0...)

A few people are asking for this on twitter, until we do the release they can try the RC with:

pip install git+https://github.com/jhelie/jupytext.git@migrate-to-jupyterlab2

[mwouts]

Jupytext 1.4.0 is now on pypi. Within a few hours it should also become available on conda-forge.

That version includes a version of the extension that works with Jupyter Lab 2.0. Please note that it won't work with Jupyter Lab 1.x - cf. the CHANGELOG.

Let me thank again @jhelie for his PR!

[mwouts]

While reading the latest plotly changelog, I see that they managed to make their JupyterLab extension work in both JupyterLab 1.x and 2.0. There extension only depends on jupyter-widgets/base, and they seem to use a magic pattern "^2.0.0 || ^3.0.0" to achieve this:

"dependencies": {
    "plotly.js": "^1.52.2",
    "@jupyter-widgets/base": "^2.0.0 || ^3.0.0",
    "lodash": "^4.17.4"
  },

Cf. https://github.com/plotly/plotly.py/pull/2261/files

We could give a try to that approach at some point later on...

[mwouts]

I realise that we probably cannot use the same trick as plotly, because there is no version 1.0 for @jupyterlab/nbformat.