Increase tag max length to 100

plugins/image-prioritizer/detect.js

@@ -153,8 +153,8 @@ function handleLCPMetric( metric, isDebug ) {
 			return;
 		}
 
-		// Also skip Custom Elements which have excessively long tag names.
-		if ( entry.element.tagName.length > 25 ) {
+		// Also skip Custom Elements which have excessively long tag names. This is the maxLength defined in image_prioritizer_add_element_item_schema_properties().
+		if ( entry.element.tagName.length > 100 ) {
 			if ( isDebug ) {
 				log(
 					`Skipping very long tag name: ${ entry.element.tagName }`
@@ -164,6 +164,7 @@ function handleLCPMetric( metric, isDebug ) {
 		}
 
 		// Note that getAttribute() is used instead of properties so that null can be returned in case of an absent attribute.
+		// The maxLengths are defined in image_prioritizer_add_element_item_schema_properties().
 		const id = entry.element.getAttribute( 'id' );
 		if ( typeof id === 'string' && id.length > 100 ) {
 			if ( isDebug ) {

plugins/image-prioritizer/helper.php

@@ -135,8 +135,11 @@ function image_prioritizer_add_element_item_schema_properties( array $additional
 				'type'      => 'string',
 				'required'  => true,
 				'minLength' => 1,
-				'maxLength' => 25, // The longest HTML tag name is 10 characters (BLOCKQUOTE and FIGCAPTION). This maxLength accounts for possible Custom Elements that are even longer.
-				'pattern'   => '^[a-zA-Z0-9\-]+$', // Technically emoji can be allowed in a custom element's tag name, but this is not supported here.
+				// The longest HTML tag name is 10 characters (BLOCKQUOTE and FIGCAPTION), but SVG tag names can be longer
+				// (e.g. feComponentTransfer). This maxLength accounts for possible Custom Elements that are even longer,
+				// although the longest known Custom Element from HTTP Archive is 32 characters. See data from <https://almanac.httparchive.org/en/2024/markup#fig-18>.
+				'maxLength' => 100,
+				'pattern'   => '^[a-zA-Z0-9\-]+\z', // Technically emoji can be allowed in a custom element's tag name, but this is not supported here.
 			),
 			'id'    => array(
 				'type'      => array( 'string', 'null' ),