Prevent Gutenberg Block from deletion

blockDeletionBlocker.js

const blockNameToPrevent = 'core/block';

const getBlockList = () => wp.data.select( 'core/block-editor' ).getBlocks();
let blockList = getBlockList();
	wp.data.subscribe( () => {
		const newBlockList = getBlockList();
		const blockListChanged = newBlockList !== blockList;

		if ( blockListChanged && newBlockList.length < blockList.length ) {
			const removedBlock = blockList.filter( ( x ) => ! newBlockList.includes( x ) )[ 0 ];
			if ( ! removedBlock || removedBlock.name !== blockNameToPrevent ) {
				return;
			}

			const removedBlockIndex = blockList.indexOf( removedBlock );

			warningBlock = wp.blocks.createBlock( 'core/block', { ref: removedBlock.attributes.ref } );

			wp.data.dispatch( 'core/block-editor' ).insertBlocks( warningBlock, removedBlockIndex );
			blockList = newBlockList;
		}
	} );

blockDeletionBlocker.js