Switch to only opting in for navigation block

lib/block-supports/typography.php

@@ -53,17 +53,16 @@ function gutenberg_register_typography_support( $block_type ) {
  * @return array Font size CSS classes and inline styles.
  */
 function gutenberg_apply_typography_support( $block_type, $block_attributes ) {
-	$has_font_size_support = false;
-	$classes               = array();
-	$styles                = array();
-	if ( property_exists( $block_type, 'supports' ) ) {
-		$has_font_size_support = gutenberg_experimental_get( $block_type->supports, array( 'fontSize' ), false );
+	if ( ! property_exists( $block_type, 'supports' ) ) {
+		return $attributes;
 	}
 
-	$has_line_height_support = false;
-	if ( property_exists( $block_type, 'supports' ) ) {
-		$has_line_height_support = gutenberg_experimental_get( $block_type->supports, array( 'lineHeight' ), false );
-	}
+	$classes = array();
+	$styles  = array();
+
+	$has_font_size_support      = gutenberg_experimental_get( $block_type->supports, array( 'fontSize' ), false );
+	$has_line_height_support    = gutenberg_experimental_get( $block_type->supports, array( 'lineHeight' ), false );
+	$has_text_transform_support = gutenberg_experimental_get( $block_type->supports, array( '__experimentalTextTransform' ), false );
 
 	// Font Size.
 	if ( $has_font_size_support ) {
@@ -87,6 +86,14 @@ function gutenberg_apply_typography_support( $block_type, $block_attributes ) {
 		}
 	}
 
+	// Text Transform.
+	if ( $has_text_transform_support ) {
+		$text_transform_style = gutenberg_typography_get_css_variable_inline_style( $block_attributes, 'textTransform', 'text-transform' );
+		if ( $text_transform_style ) {
+			$styles[] = $text_transform_style;
+		}
+	}
+
 	$attributes = array();
 	if ( ! empty( $classes ) ) {
 		$attributes['class'] = implode( ' ', $classes );
@@ -106,3 +113,34 @@ function gutenberg_apply_typography_support( $block_type, $block_attributes ) {
 		'apply'              => 'gutenberg_apply_typography_support',
 	)
 );
+
+/**
+ * Generates an inline style for a typography feature e.g. text decoration,
+ * text transform, and font style.
+ *
+ * @param array  $attributes   Block's attributes.
+ * @param string $feature      Key for the feature within the typography styles.
+ * @param string $css_property Slug for the CSS property the inline style sets.
+ *
+ * @return string              CSS inline style.
+ */
+function gutenberg_typography_get_css_variable_inline_style( $attributes, $feature, $css_property ) {
+	// Retrieve current attribute value or skip if not found.
+	$style_value = gutenberg_experimental_get( $attributes, array( 'style', 'typography', $feature ), false );
+	if ( ! $style_value ) {
+		return;
+	}
+
+	// If we don't have a preset CSS variable, we'll assume it's a regular CSS value.
+	if ( strpos( $style_value, "var:preset|{$css_property}|" ) === false ) {
+		return sprintf( '%s:%s;', $css_property, $style_value );
+	}
+
+	// We have a preset CSS variable as the style.
+	// Get the style value from the string and return CSS style.
+	$index_to_splice = strrpos( $style_value, '|' ) + 1;
+	$slug            = substr( $style_value, $index_to_splice );
+
+	// Return the actual CSS inline style e.g. `text-decoration:var(--wp--preset--text-decoration--underline);`.
+	return sprintf( '%s:var(--wp--preset--%s--%s);', $css_property, $css_property, $slug );
+}

packages/block-library/src/heading/block.json

@@ -29,7 +29,6 @@
 		},
 		"fontSize": true,
 		"lineHeight": true,
-		"__experimentalTextTransform": true,
 		"__experimentalSelector": {
 			"core/heading/h1": "h1",
 			"core/heading/h2": "h2",

packages/block-library/src/navigation/block.json

@@ -50,6 +50,7 @@
 		"html": false,
 		"inserter": true,
 		"fontSize": true,
+		"__experimentalTextTransform": true,
 		"color": {
 			"textColor": true,
 			"backgroundColor": true