REST API: Only cast scalar types to string when comparing new & old meta values.

Newly-supported array and object meta types should not be cast to strings.

Props TimothyBlynJacobs, caercam.
Fixes #47928.


git-svn-id: https://develop.svn.wordpress.org/trunk@45903 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-includes/rest-api/fields/class-wp-rest-meta-fields.php

@@ -350,9 +350,17 @@ abstract class WP_REST_Meta_Fields {
 		// Do the exact same check for a duplicate value as in update_metadata() to avoid update_metadata() returning false.
 		$old_value = get_metadata( $meta_type, $object_id, $meta_key );
 		$subtype   = get_object_subtype( $meta_type, $object_id );
+		$args      = $this->get_registered_fields()[ $meta_key ];
 
 		if ( 1 === count( $old_value ) ) {
-			if ( (string) sanitize_meta( $meta_key, $value, $meta_type, $subtype ) === $old_value[0] ) {
+			$sanitized = sanitize_meta( $meta_key, $value, $meta_type, $subtype );
+
+			if ( in_array( $args['type'], array( 'string', 'number', 'integer', 'boolean' ), true ) ) {
+				// The return value of get_metadata will always be a string for scalar types.
+				$sanitized = (string) $sanitized;
+			}
+
+			if ( $sanitized === $old_value[0] ) {
 				return true;
 			}
 		}

tests/phpunit/tests/rest-api/rest-post-meta-fields.php

@@ -2120,6 +2120,90 @@ class WP_Test_REST_Post_Meta_Fields extends WP_Test_REST_TestCase {
 		$this->assertEquals( array( 'BuddyPress' ), $meta[1] );
 	}
 
+	/**
+	 * @ticket 47928
+	 */
+	public function test_update_meta_with_unchanged_array_values() {
+		register_post_meta(
+			'post',
+			'list',
+			array(
+				'single'       => true,
+				'type'         => 'array',
+				'show_in_rest' => array(
+					'schema' => array(
+						'type'  => 'array',
+						'items' => array(
+							'type' => 'string',
+						),
+					),
+				),
+			)
+		);
+
+		add_post_meta( self::$post_id, 'list', array( 'WordCamp' ) );
+
+		$this->grant_write_permission();
+
+		$request = new WP_REST_Request( 'PUT', sprintf( '/wp/v2/posts/%d', self::$post_id ) );
+		$request->set_body_params(
+			array(
+				'meta' => array(
+					'list' => array( 'WordCamp' ),
+				),
+			)
+		);
+
+		$response = rest_get_server()->dispatch( $request );
+		$this->assertEquals( 200, $response->get_status() );
+
+		$data = $response->get_data();
+		$this->assertEquals( array( 'WordCamp' ), $data['meta']['list'] );
+	}
+
+	/**
+	 * @ticket 47928
+	 */
+	public function test_update_meta_with_unchanged_object_values() {
+		register_post_meta(
+			'post',
+			'object',
+			array(
+				'single'       => true,
+				'type'         => 'object',
+				'show_in_rest' => array(
+					'schema' => array(
+						'type'       => 'object',
+						'properties' => array(
+							'project' => array(
+								'type' => 'string',
+							),
+						),
+					),
+				),
+			)
+		);
+
+		add_post_meta( self::$post_id, 'object', array( 'project' => 'WordCamp' ) );
+
+		$this->grant_write_permission();
+
+		$request = new WP_REST_Request( 'PUT', sprintf( '/wp/v2/posts/%d', self::$post_id ) );
+		$request->set_body_params(
+			array(
+				'meta' => array(
+					'object' => array( 'project' => 'WordCamp' ),
+				),
+			)
+		);
+
+		$response = rest_get_server()->dispatch( $request );
+		$this->assertEquals( 200, $response->get_status() );
+
+		$data = $response->get_data();
+		$this->assertEquals( array( 'project' => 'WordCamp' ), $data['meta']['object'] );
+	}
+
 	/**
 	 * Internal function used to disable an insert query which
 	 * will trigger a wpdb error for testing purposes.