JupyterLab 2 support

[consideRatio]

When installing this extension on JupyterLab 2 I noted the following warning.

WARNING in @jupyter-widgets/base
      Multiple versions of @jupyter-widgets/base found:
        1.2.5 ./~/@jupyter-widgets/jupyterlab-sidecar/~/@jupyter-widgets/base from ./~/@jupyter-widgets/jupyterlab-sidecar/~/@jupyter-widgets/base/lib/index.js
        3.0.0 ./~/@jupyter-widgets/jupyterlab-manager/~/@jupyter-widgets/base from ./~/@jupyter-widgets/jupyterlab-manager/~/@jupyter-widgets/base/css/index.css

This PR attempts to fix support for JupyterLab 2, but my knowledge of JupyterLab and TypeScript is lacking to complete this PR. I hope that someone else can complete it!

What I've done

• Updated all dependencies in package.json
• Added "esModuleInterop": true, in tsconfig.json to workaround an typescript compile error that probably can be resolved in a better manner.
• Added @lumino/coreutils as a dependency, as @phosphor/coreutils was used as a dependency but not specified as one in plugin.ts.
• Got help from @jasongrout to resolve some typescript compilation issues
• Resolved one issue with the npm run test:chrome test, but it crash later with another issue. But...

What I have not done

I've not fixed the tests entirely, I still crash with ReferenceError: regeneratorRuntime is not defined after my browser starts. I assume it is because these tests never have been configured to run successfully before (#19). As the tests are unrelated to this PR, and I failed to fix them in 1 hour, I'll settle now and suggest this is ready for merge.

[consideRatio]

@jasongrout, this extension have a dependency on jupyterlab-manager, is that a mistake? I found the following references in the code base.

jupyterlab-sidecar/src/widget.ts

Lines 4 to 8 in 720747a

	// TODO: import from @jupyter-widgets/jupyterlab-manager once Output is
	// exported by the main module.
	import {
	OutputModel
	} from '@jupyter-widgets/jupyterlab-manager/lib/output';

jupyterlab-sidecar/src/plugin.ts

Lines 16 to 18 in 720747a

	import {
	output
	} from '@jupyter-widgets/jupyterlab-manager';

[jasongrout]

@jasongrout, this extension have a dependency on jupyterlab-manager, is that a mistake? I found the following references in the code base.

The sidecar explicitly uses jupyterlab-specific things, so yes, it is appropriate to have a dependency. That widget only works in jlab.

Most widgets are not only for jlab, and probably should not depend on the jlab widget manager.

[kylebarron]

What else is needed to move this PR forward?

[jasongrout]

It looks like we just need someone to test it, merge it, and release it. Can you test it?

[kylebarron]

I might be able to find some time this weekend.

Are you also looking for new test cases in the PR, or just to, e.g. test ipyleaflet on this branch?

[jasongrout]

Are you also looking for new test cases in the PR, or just to, e.g. test ipyleaflet on this branch?

I'm not looking for new test cases. I think testing ipyleaflet on this branch should be fine.

[bernhard-42]

I also tried to fix it based on this PR.
It compiles, it works in the browser (nice) and the karma test run - however they fail.
Don't know why up to now

[bernhard-42]

btw. this is where both tests fail:

  Sidecar
    SidecarModel
16 04 2020 20:47:01.047:WARN [reporter]: SourceMap position not found for trace:     at SidecarModel.initialize (base/src/widget.js?61103a732e53ec236c6426e01399c25f38578cd9:5:1146)
16 04 2020 20:47:01.047:WARN [reporter]: SourceMap position not found for trace:     at new SidecarModel (base/src/widget.js?61103a732e53ec236c6426e01399c25f38578cd9:5:465)
      ✖ should be createable
        Chrome 80.0.3987 (Mac OS X 10.15.4)
      TypeError: Cannot read property 'sessionContext' of undefined
          at SidecarModel.initialize (/var/folders/6f/_pgkb3vj1637f9h4whkg1_200000gn/T/karma-typescript-bundle-917476LFXqTwYv1g2.js:134944:35)
          at SidecarModel.initialize (src/widget.js:5:1146)

[bernhard-42]

Looks like the DummyManager needs to be extended to have a mock Context (the access to widget_manager.context.sessionContext.kernelChanged.connect fails)
This goes beyond my understanding of the jupyterlab internals, happily leaving the field to others who know more about it ...

[jasongrout]

Thanks for tracking that down. @vidartf - have you happened to address this in your opinionated ts cookiecutter?

[jasongrout]

On the other hand, I agree with @consideRatio:

I've not fixed the tests entirely, I still crash with ReferenceError: regeneratorRuntime is not defined after my browser starts. I assume it is because these tests never have been configured to run successfully before (#19). As the tests are unrelated to this PR, and I failed to fix them in 1 hour, I'll settle now and suggest this is ready for merge.

The tests failing was already an issue, and I think can be solved on another issue. You tested this PR and it was working in jlab 2. Thanks!

[jasongrout]

Thanks everyone. I just released sidecar version version 0.4.0 and it works in jlab 2.

[bernhard-42]

@jasongrout @consideRatio For the records, I could solve the regenerator error by adding regenerator-runtime and core-js to dev dependencies and including node_modules/regenerator-runtime/runtime.js into the karma config, see bernhard-42@1550977
But then the tests fail with the above sessionContext error

Maybe this helps in the future to get the tests running again

[jasongrout]

Would you mind submitting a PR with your changes? I had a difficult time getting the tests even to the point of running and getting any sort of error. Once I can get things to having that sessionContext error, it will be much easier to fix things.

[vidartf]

@vidartf - have you happened to address this in your opinionated ts cookiecutter?

I don't think so, as most widgets don't interact directly with the session/kernel.

[bernhard-42]

@jasongrout created #47.
Hope it is ok that it is not rebased to your merge yesterday ...