Blocks: add parse_blocks filter to parse_blocks()

src/wp-includes/blocks.php

@@ -2242,6 +2242,7 @@ function render_block( $parsed_block ) {
  * Parses blocks out of a content string.
  *
  * @since 5.0.0
+ * @since 6.?.? The `parse_blocks` filter was added.
  *
  * @param string $content Post content.
  * @return array[] {
@@ -2271,7 +2272,17 @@ function parse_blocks( $content ) {
 	$parser_class = apply_filters( 'block_parser_class', 'WP_Block_Parser' );
 
 	$parser = new $parser_class();
-	return $parser->parse( $content );
+
+
+	/**
+	* Filter the collection of parsed blocks.
+	*
+	* @since 6.?.?
+	*
+	* @param array[] $blocks Array of parsed block objects.
+	* @param string  $content The content that is being parsed.
+	*/
+	return apply_filters( 'parse_blocks', $parser->parse( $content ), $content );
 }
 
 /**