fix(ProfilingPlugin): complete after the writeStream had finished flu…

…shing the data to the filesystem

Fixes a race-condition where `events.json` might not yet be available immediately after compilation.

lib/debug/ProfilingPlugin.js

@@ -73,17 +73,18 @@ class Profiler {
 
 /**
  * @param {string} outputPath The location where to write the log.
- * @returns {{trace: ?,	counter: number, profiler: Profiler}} The trace object
+ * @returns {{trace: ?,	counter: number, profiler: Profiler, fsStream: WriteStream}} The trace object
  */
 function createTrace(outputPath) {
 	const trace = new Trace({
 		noStream: true
 	});
 	const profiler = new Profiler(inspector);
+	const fsStream = fs.createWriteStream(outputPath);
 
 	let counter = 0;
 
-	trace.pipe(fs.createWriteStream(outputPath));
+	trace.pipe(fsStream);
 	// These are critical events that need to be inserted so that tools like
 	// chrome dev tools can load the profile.
 	trace.instantEvent({
@@ -119,7 +120,8 @@ function createTrace(outputPath) {
 	return {
 		trace,
 		counter,
-		profiler
+		profiler,
+		fsStream
 	};
 }
 
@@ -169,16 +171,17 @@ class ProfilingPlugin {
 		);
 
 		// We need to write out the CPU profile when we are all done.
-		compiler.hooks.done.tap(
+		compiler.hooks.done.tapAsync(
 			{
 				name: pluginName,
 				stage: Infinity
 			},
-			() => {
+			(stats, callback) => {
 				tracer.profiler.stopProfiling().then(parsedResults => {
 					if (parsedResults === undefined) {
 						tracer.profiler.destroy();
 						tracer.trace.flush();
+						tracer.fsStream.end(callback);
 						return;
 					}
 
@@ -226,6 +229,7 @@ class ProfilingPlugin {
 
 					tracer.profiler.destroy();
 					tracer.trace.flush();
+					tracer.fsStream.end(callback);
 				});
 			}
 		);