Restore edit-comments-faster on review comments

[kidonng]

Maybe a continuation of #2992

Obsolete information

Explanation of the lazy load logic mentioned in #3396

.js-minimizable-comment-group
	.minimized-comment // Invisible
		...
			details-menu
				.js-comment-edit-button // A
    .js-comment
		...
			details-menu[src]
				// Contents are lazy loaded when you hover the three dots menu
				.js-comment-edit-button // B

1. Why Up arrow to edit own comment is broken #3388 happens: comment-fields-keyboard-shortcuts tries to find B which isn't loaded yet
2. Why edit-comments-faster in review comments doesn't work: only A triggers the function and the icon is added into an invisible container
3. Why Up arrow to edit own comment is broken #3388 (comment) happens: B loads and triggers the function and the icon is added into an invisible container

This PR

• Determine if it's A triggering the function, and add the edit icon to the correct location in review comments (fix 2)
• Skip if it's B triggering the function, to prevent duplicate icon addition (fix 3)
• Upgrade to selector-observer, fix "Edit comment" button injection is not reliable #3279
• Rewrite the feature to fix existing issues

Test: A PR with review comments (like https://github.com/sindresorhus/refined-github/pull/3405#discussion_r460863841)

[fregante]

This seems unnecessary. As I suggested earlier, the solution is to create a brand-new button instead of cloning the existing one. This way you just need to select the emoji dropdown and avoid all this document traversing/filtering.

[kidonng]

Filtering is needed because there can be two edit buttons in a single review comment.

Check out the latest code, maybe the simplest one.

[fregante]

Please always provide a link where this is testable, as requested in the PR template.

And what it fixes exactly

[kidonng]

Sorry, added test link and make what this PR does more clear.

I just found there are still rooms for improvement: currently it doesn't work if you unresolve a conversation

[kidonng]

Seems like GitHub removed the aforementioned lazy load logic, so this bug doesn't exist anymore. Closing for the moment.

Update on 2020-08-24: it is back 😥

[kidonng]

After using selector-observer it works for unresolved conversations 🎉

[fregante]

I'm still seeing the lazy-loaded context-menus. For the 3rd time, do not use cloneNode. Just generate the link via JSX.

[kidonng]

I'm still seeing the lazy-loaded context-menus

That's why I reopened this PR (though it now also includes upgrading to selector-observer)

For the 3rd time, do not use cloneNode

🤷‍♀️ That cloneNode is not written by me

[fregante]

Thank you!

Note: hasComment automatically implies a comment event listener though. This has no effect since we use onetime, but we should keep it in mind.

Perhaps we can remove that implication once we refactor every/most hasComments feature to use selector-observer

[kidonng]

I reverted 9c147cd with new selectors. Tested on other repos where I have permissions, the edit button appears on where it should.

[fregante]

2.3 months in the making

🥳

[yakov116]

Not sure what broke here. After this PR on #3621 only the first comment has a edit icon. the rest throw a whole bunch of console errors.

[fregante]

Hidden comments break the feature because they have no reaction button. The observe selector needs to be updated