demoErrorSaveWithTitle.js

( function(
	blocks,
	blockEditor,
    element,
    data
) {
	var el = element.createElement;
	var InnerBlocks = blockEditor.InnerBlocks;
	blocks.registerBlockType( 'demo/demo-block', {
		title: 'Demo',
		category: 'common',
		attributes: {},
		edit: function( props ) {
			return el(
				'div',
				{},
				'After:' + data.select('core/editor').getEditedPostAttribute('title'),
			);
		},
		save: function( props ) {
            return el(
				'div',
				{}, 
				'After:' + data.select('core/editor').getEditedPostAttribute('title'),
			);
		},
	} )
} ) (
	window.wp.blocks,
	window.wp.blockEditor,
    window.wp.element,
    window.wp.data,
);