I/6154: Allow selection on object element (ie. on table cells)

[jodator]

Suggested merge commit message (convention)

Enhancement: Allow selection on object elements. Closes ckeditor/ckeditor5#6154.

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Additional information

• This PR introduces required selection post-fixer changes for table selection.

• Those are a minimal engine changes required to allow multi-range selection on object elements (table cells).

• Two tests in image and table were required update because a test case:

[]<object></object>

was post-fixed by proposed post-fixer to:

[<object></object>]

fixed to:

<paragraph>[]</paragraph><object></object>

This case might need to be checked wheter it is OK or not.

Sub PRs:

• 6154: Align test code to the latest changes in selection post-fixer. ckeditor5-image#341
• 6154: Align test code to the latest changes in selection post-fixer. ckeditor5-table#229

[coveralls]

Coverage remained the same at 100.0% when pulling 007da5b on i/6154 into 48bea53 on master.

[Reinmar]

From what I can see you mostly removed outdated code and added this single function for fixing intersecting ranges. That sounds fine. I guess we could have some more tests for some less and more ugly scenarios. E.g.:

• a couple of cells selected, but not like now when one's directly next to another,
• some selection around rows – like [<td>x</td>]<td>x</td>[<td>x</td></tr>],

Also, I thought about a case when one range is inside a cell and the other outside. Maybe it should be a general rule that if a single range is an object range, all ranges must be object ranges?

[Reinmar]

As commented.

[jodator]

@Reinmar I've added some scenarios and when thinking about other ones it looked like they're covered elsewhere (mostly by the limit boundary-crossing tests). One test already spotted some error in the code so that one got fixed.

[jodator]

Self R- 👎

Do not merge.

[jodator]

Self R+ 👍

It turned out to be some problems with manual tests during refactoring.

Review ;)

[Reinmar]

BTW, there's no "Enhancement" type of change yet. I usually use "Other".