childWithNoInserter.js

( function() {
	var registerBlockType = wp.blocks.registerBlockType;
	var el = wp.element.createElement;
	var InnerBlocks = wp.editor.InnerBlocks;

	registerBlockType( 'test/parent', {
		title: 'Test Parent',
		icon: 'cart',
		category: 'common',

		edit: function() {
			return el( 'div', { style: { outline: '1px solid gray', padding: 5 } },
				el(
					InnerBlocks,
					{
						template:  [
							[ 'test/child' ],
						],
						templateLock: false,
					}
				)
			);
		},

		save: function() {
			return el( 'div', { style: { outline: '1px solid gray', padding: 5 } },
				el( InnerBlocks.Content, {} )
			);
		},
	} );

	registerBlockType( 'test/child', {
		title: 'Test Child',
		icon: 'cart',
		category: 'common',
		parent: [ 'test/parent' ],
		supports: {
			inserter: false,
		},

		edit: function() {
			return 'Child';
		},

		save: function() {
			return 'Child';
		},
	} );
} )();