Extend entities in DraftJS when typing next to them.

index.js

/*
DraftJS Slack - #general
Jimj 02/08/2018 [8:13 AM]
@ddelrio Simplest solution I found for continuing entities is, in beforeInputHanded :
*/
const prev_char_space = this.getCharFromSelection() === ' '
   const new_char_space = char === ' '
   const prev_ent = this.getEntityAtSelection()
   if (prev_ent && (!prev_char_space || !new_char_space)) {
     const contentStateWithEntity = Modifier.insertText(
       editorState.getCurrentContent(),
       selection, char, null, prev_ent );
     const newEditorState: Draft.EditorState = Draft.EditorState.push(
       editorState, contentStateWithEntity, "insert-characters");
     this.setState({ editorState: newEditorState });
     return 'handled'
   }
   //out
   if ( prev_ent && prev_char_space && new_char_space) {
     let contentStateWithEntity = Modifier.replaceText( editorState.getCurrentContent(),
       selection.merge({ anchorOffset: currentOffset - 1, focusOffset: currentOffset }),
       ' ', null, null
     );
     let newEditorState: Draft.EditorState = Draft.EditorState.push(
       editorState, contentStateWithEntity, "insert-characters")
     this.setState({ editorState: newEditorState });
     return 'handled'
   }