Reinstate edit_theme_options check and add test coverage

lib/class-wp-rest-global-styles-controller-gutenberg.php

@@ -540,7 +540,6 @@ public function get_item_schema() {
 	public function get_theme_item_permissions_check( $request ) { // phpcs:ignore VariableAnalysis.CodeAnalysis.VariableAnalysis.UnusedVariable
 		/*
 		 * Verify if the current user has edit_posts capability.
-		 * This capability is required to view global styles.
 		 */
 		if ( current_user_can( 'edit_posts' ) ) {
 			return true;
@@ -552,6 +551,13 @@ public function get_theme_item_permissions_check( $request ) { // phpcs:ignore V
 			}
 		}
 
+		/*
+		 * Verify if the current user has edit_theme_options capability.
+		 */
+		if ( current_user_can( 'edit_theme_options' ) ) {
+			return true;
+		}
+
 		return new WP_Error(
 			'rest_cannot_read_global_styles',
 			__( 'Sorry, you are not allowed to access the global styles on this site.', 'gutenberg' ),

phpunit/class-wp-rest-global-styles-controller-gutenberg-test.php

@@ -22,6 +22,11 @@ class WP_REST_Global_Styles_Controller_Gutenberg_Test extends WP_Test_REST_Contr
 	 */
 	protected static $subscriber_id;
 
+	/**
+	 * @var int
+	 */
+	protected static $theme_manager_id;
+
 	/**
 	 * @var int
 	 */
@@ -61,6 +66,18 @@ public static function wpSetupBeforeClass( $factory ) {
 			)
 		);
 
+		self::$theme_manager_id = $factory->user->create(
+			array(
+				'role' => 'subscriber',
+			)
+		);
+
+		// Add the 'edit_theme_options' capability to the theme manager (subscriber).
+		$theme_manager_id = get_user_by('id', self::$theme_manager_id );
+		if ( $theme_manager_id instanceof WP_User ) {
+			$theme_manager_id->add_cap('edit_theme_options');
+		}
+
 		// This creates the global styles for the current theme.
 		self::$global_styles_id = $factory->post->create(
 			array(
@@ -83,7 +100,9 @@ public static function wpSetupBeforeClass( $factory ) {
 	 */
 	public static function wpTearDownAfterClass() {
 		self::delete_user( self::$admin_id );
+		self::delete_user( self::$editor_id );
 		self::delete_user( self::$subscriber_id );
+		self::delete_user( self::$theme_manager_id );
 	}
 
 	/**
@@ -236,6 +255,22 @@ public function test_get_theme_item_editor_permission_check() {
 		$this->assertArrayHasKey( 'self', $links, 'Links do not have a "self" key' );
 	}
 
+	/**
+	 * @covers WP_REST_Global_Styles_Controller_Gutenberg::get_theme_item
+	 */
+	public function test_get_theme_item_theme_options_manager_permission_check() {
+		wp_set_current_user( self::$theme_manager_id );
+		switch_theme( 'emptytheme' );
+		$request  = new WP_REST_Request( 'GET', '/wp/v2/global-styles/themes/emptytheme' );
+		$response = rest_get_server()->dispatch( $request );
+		// Checks that the response has the expected keys.
+		$data  = $response->get_data();
+		$links = $response->get_links();
+		$this->assertArrayHasKey( 'settings', $data, 'Data does not have "settings" key' );
+		$this->assertArrayHasKey( 'styles', $data, 'Data does not have "styles" key' );
+		$this->assertArrayHasKey( 'self', $links, 'Links do not have a "self" key' );
+	}
+
 	/**
 	 * @covers WP_REST_Global_Styles_Controller_Gutenberg::get_theme_item
 	 */