Add a apply filters to allowed blocks to enable extending

Author: mkaz

packages/block-library/src/social-links/edit.js

@@ -28,6 +28,7 @@ import {
 	ToolbarItem,
 	ToolbarGroup,
 } from '@wordpress/components';
+import { applyFilters } from '@wordpress/hooks';
 import { __ } from '@wordpress/i18n';
 import { check } from '@wordpress/icons';
 
@@ -91,9 +92,15 @@ export function SocialLinksEdit( props ) {
 		[ `items-justified-${ itemsJustification }` ]: itemsJustification,
 	} );
 
+	// Filter to allow additional social link blocks
+	const FilteredAllowedBlocks = applyFilters(
+		'editor.SocialLinks.allowedBlocks',
+		ALLOWED_BLOCKS
+	);
+
 	const blockProps = useBlockProps( { className } );
 	const innerBlocksProps = useInnerBlocksProps( blockProps, {
-		allowedBlocks: ALLOWED_BLOCKS,
+		allowedBlocks: FilteredAllowedBlocks,
 		orientation: 'horizontal',
 		placeholder: SocialPlaceholder,
 		templateLock: false,