new-block-draft.js

function addEmptyBlock(editorState) {
    const newBlock = new ContentBlock({
        key: genKey(),
        type: 'unstyled',
        text: '',
        characterList: List(),
    });

    const contentState = editorState.getCurrentContent();
    const newBlockMap = contentState.getBlockMap().set(newBlock.key, newBlock);
    const editorWithBlock = EditorState.push(
        editorState,
        ContentState.createFromBlockArray(newBlockMap.toArray())
    );
    return EditorState.moveFocusToEnd(editorWithBlock);
}