Check error code instead of string

Author: oandregal

lib/global-styles.php

@@ -81,9 +81,9 @@ function gutenberg_experimental_global_styles_get_from_file( $file_path ) {
 			true
 		);
 
-		$json_decoding_error = json_last_error_msg();
-		if ( 'No error' !== $json_decoding_error ) {
-			error_log( 'Error when decoding file schema: ' . $json_decoding_error );
+		$json_decoding_error = json_last_error();
+		if ( JSON_ERROR_NONE !== $json_decoding_error ) {
+			error_log( 'Error when decoding file schema: ' . json_last_error_msg() );
 			return $config;
 		}
 
@@ -105,9 +105,9 @@ function gutenberg_experimental_global_styles_get_user() {
 	if ( array_key_exists( 'post_content', $user_cpt ) ) {
 		$decoded_data = json_decode( $user_cpt['post_content'], true );
 
-		$json_decoding_error = json_last_error_msg();
-		if ( 'No error' !== $json_decoding_error ) {
-			error_log( 'Error when decoding user schema: ' . $json_decoding_error );
+		$json_decoding_error = json_last_error();
+		if ( JSON_ERROR_NONE !== $json_decoding_error ) {
+			error_log( 'Error when decoding user schema: ' . json_last_error_msg() );
 			return $config;
 		}