browser friendly flushTime

src/utils/flushTime.js

@@ -1,19 +1,35 @@
 const DEBUG = false;
 const map = new Map;
 
+let time;
+
+if ( typeof process === 'undefined' ) {
+	time = function time ( previous ) {
+		const now = window.performance.now();
+		return previous ? previous - now : now;
+	};
+} else {
+	time = function time ( previous ) {
+		const hrtime = process.hrtime( previous );
+		if ( previous ) {
+			return hrtime[0] * 1e3 + hrtime[1] / 1e6;
+		}
+	};
+}
+
 export function timeStart ( label ) {
 	if ( !map.has( label ) ) {
 		map.set( label, {
 			time: 0
 		});
 	}
-	map.get( label ).start = process.hrtime();
+	map.get( label ).start = time();
 }
 
 export function timeEnd ( label ) {
 	if ( map.has( label ) ) {
 		const item = map.get( label );
-		item.time += toMilliseconds( process.hrtime( item.start ) );
+		item.time += time( item.start );
 	}
 }
 
@@ -24,10 +40,6 @@ export function flushTime ( log = defaultLog ) {
 	map.clear();
 }
 
-function toMilliseconds ( time ) {
-	return time[0] * 1e+3 + Math.floor( time[1] * 1e-6 );
-}
-
 function defaultLog ( label, time ) {
 	if ( DEBUG ) {
 		/* eslint-disable no-console */