2021-03-02 Release UX and Data Part II - The UXening.

[rtibbles]

Fixes for:

#2895:
Test 1 (no errors/regressions): Create a new channel as a user without a default language set. Don't add a language. On close, you should see a front-end validation error and be prompted to fill in the language before the form closes.
Test 2 (to account for this edge case): Create a new channel as a user with a default language that had been previously set. Don't add a language. On close, you should see a front-end validation error and be prompted to fill in the language before the form closes.

#2904 - Unsure how to replicate for user, backend only change.

#2977 - Check that publish modal does not appear briefly after sync task is started

#2757 - Check that Khan Academy has the same number of resources listed on its Channel card as in the channel edit/view page

#2988 - Check that you can delete a channel from that channel's channel edit page

#2889 - Create a new channel, check that the ADD text shows up

#2927 - Ensure that you can copy from the clipboard into an empty channel

#2937 - In Chrome dev tools 'Network' tab, set Network connection to '3G' to ensure a slower connection. Try to login, ensure that the login button disables after a first click.

#2470 - Ensure that you can move content from the clipboard into a channel

#2724 - Ensure that content disappears when deleted from the clipboard

#2802 - Ensure that content copied into the clipboard before the relaunch is able to be unfolded, seen, and moved into a channel

#2818 - Ensure that selecting content in the clipboard by just selecting the checkbox next to the channel will cause them to be copied

N.B.
This includes a lot of changes to the clipboard in general, so doing a full pass on the clipboard would be helpful.

[radinamatic]

@metodimilevqa

I'll test #2895, I have user accounts for both cases.

For #2937: this feature is usually under throttling.

Firefox

Chrome

[radinamatic]

@metodimilevqa & I confirmed all the fixes included in this release, some follow-up issues remain to be addressed in the future ones.

I'll approve the PR to get the release merged in production as there seem to be no regressions, but I do have one comment regarding the clipboard navigation: using Firefox still gives painfully slower experience compared to Chrome 😞

I have not seen consistently replicable errors in the console, but someone with many nodes in the clipboard (as probably many serious curators do), responsiveness of Studio in Firefox while navigating (opening & closing) nested topics will be a serious patience stress test.

[radinamatic]

UXening is ready to fly!!! 👍🏽

[micahscopes]

Wow! There's a lot of stuff in here. It's definitely possible that I missed something, but I didn't notice anything glaringly off.