Arrow navigation broken in Firefox

[ellatrix]

To reproduce, create e.g. two paragraphs in Firefox and try to use the arrow keys to move the caret from one to another. Normally this should work. In Firefox it does not. The selection API probably behaves a bit different there, though I'm pretty sure it used to work.

[ellatrix]

Related: #2222. Also related: pressing arrow twice in empty editable. Looking for an alternative solution that may give a better experience too.

[tg-ephox]

@iseulde are you also looking at #2222? I plan to look at this next if not.
Also @EphoxJames is working on #2392 will this issue overlap with that?

[tg-ephox]

@iseulde part of the problem with this issue is around links. When you left or right arrow through the TinyMCE editor, as it gets to a link the cursor position stays the same when it changes the style to display the link. That causes this code to assume the beginning or end of the block has been reached:

gutenberg/editor/modes/visual-editor/block.js

Line 294 in 595efd8

if ( range !== this.lastRange ) {

A different approach to handling this would be required though. Maybe a custom event or a callback prop on the block to say when the end of editor has been reached?

[ellatrix]

@tg-ephox Yeah I know. There's PRs such as #2431.

[ellatrix]

I should have linked to the issues.

[youknowriad]

should be fixed by #2424