Editable mentions don't support exiting when text selected

[ifiokjr]

Summary

Showcase Link

Related to #639

Mentions don't allow exit when text is selected.

Steps to reproduce

• Navigate to the showcase.
• Add the text @abc
• Hold down the Shift
• Navigate backward with the arrow key to the @ symbol.

Expected results

You should be able to select the @ symbol.

Actual results

The selection jumps to the end when of the c key at the point the selection touches the @ symbol.

Possible Solution

Preserve selection currently doesn't work for non-empty selection.

Perhaps, rather than using from and to the implementation should use the head and anchor to ensure that exiting the mention preserves the intended selection.

Something like this should be added to the preserveSelection in @remirror/core-utils.

• If the selection is empty, keep the current implementation
• Otherwise, map the original head (the movable part of the selection) and anchor (the fixed part of the selection) over the current transaction steps.
• Create a new text selection from: min(head, anchor, to: max(head, anchor) and apply it to the transaction.

Screenshot