Restore padding on main dock panel

[fcollonval]

References

Fixes #10387

Code changes

N/A

User-facing changes

Restore 5px padding on main dock panel

Backwards-incompatible changes

N/A

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[fcollonval]

Before:

After:

Multiple document	Single document

Stable version

Credit for capture goes to @krassowski

UI tests are expected to fail.

[goanpeca]

ui-tests/reference-output/screenshots/general_dark_theme.png

Should we declare these files as binary (gitignore)to avoid having to diff and any conflicts in the future?

[fcollonval]

Should we declare these files as binary (gitignore)to avoid having to diff and any conflicts in the future?

I'm not sure. If there are conflicts, this means they have been changed on master. So the PR needs to be rebased else UI tests wil fail when merging, no?

[krassowski]

Diffing them via the GitHub interface is delightful by the way:

I think we should continue reviewing them. Which brings me to a questions: @fcollonval do you happen to have ipykernel prerelease installed or was it picked up somewhere else?

[goanpeca]

I'm not sure. If there are conflicts, this means they have been changed on master. So the PR needs to be rebased else UI tests wil fail when merging, no?

I guess, but in general it does not seem like git should try to diff these files.

We can create a .gitattributes file and declare them as binary.

# 
*.png binary
*.PNG binary

Thoughts @jasongrout @mbektas @blink1073 ?

---

Update: Just missed @krassowski comment.

I guess I am not sure how the process is currently working for the UI tests, are we generating new images on every new run? (which would show what @krassowski is doing), cause I thought the new "reference" files had to be generated manually.

If we want to use the GIT diff, then we would need to generate these files on every PR so that we could check right away these differences, otherwise we are comparing between reference images, which can be useful 🤷🏼

[fcollonval]

do you happen to have ipykernel prerelease installed or was it picked up somewhere else?

Jeremy changed the CI to use the pre-release of ipykernel to test the debugger: https://github.com/jupyterlab/jupyterlab/pull/10359/files#r649835430

[jtpio]

Yes updating to the ipykernel prerelease in that PR introduced a couple of visual changes.

From #10359 (comment):

[jtpio]

I guess I am not sure how the process is currently working for the UI tests,

@goanpeca there are some instructions in https://github.com/jupyterlab/jupyterlab/tree/master/ui-tests and https://jupyterlab.readthedocs.io/en/latest/developer/contributing.html#visual-regression-and-ui-tests.

Usually we don't need to modify the reference screenshots unless there is an intentional visual change a PR wants to bring.

This PR fixes a regression that was not caught at the time because the visual regression tests were not in place yet.

[blink1073]

Thanks!