Incorrect typing result when children mutation handler tries to fix nbsp character

[oskarwrobel]

Steps to reproduce

For the following model:

<paragraph>
  <text bold="true" linkHref="sth">F[]</text><$text>oo&nbsp;bar</$text>
</paragrah>

type something e.g. x character .

Result

Selection went after &nbsp character and attributes are applied for the all text before the selection.

<paragraph>
  <text bold="true" linkHref="sth">Fxoo []</text><$text>bar</$text>
</paragrah>

Expected result

Selection should be placed after the new character

<paragraph>
  <text bold="true" linkHref="sth">Fx[]</$text><$text>oo&nbsp;bar</$text>
</paragrah>

[oskarwrobel]

See: https://github.com/ckeditor/ckeditor5-typing/blob/07d0a65b5dfe7a09039e56e5777c98c1f2a296e6/src/utils/injecttypingmutationshandling.js#L146-L181

[scofalik]

So, it seemed to me that the problem is in those two lines of code:

const newText = modelFromDomChildren.map( item => item.is( 'text' ) ? item.data : '@' ).join( '' ).replace( /\u00A0/g, ' ' );
const oldText = currentModelChildren.map( item => item.is( 'text' ) ? item.data : '@' ).join( '' );

Here we create two text strings which we will compare looking for changes. It seems that oldText should also have   changed to regular spaces for comparison purposes. Of course there always may be some case that I forgot now, but that would make sense. Above those two lines of code is a comment that mentions _handleTextMutation function. In that function oldText has &nbsp replaced.

So I changed that and there are no errors in tests and the bug seems to be fixed 🤷‍♂️ .