report time info for directories correctly

Author: sokra

lib/DirectoryWatcher.js

@@ -726,7 +726,9 @@ class DirectoryWatcher extends EventEmitter {
 		} else {
 			for (const dir of this.directories.keys()) {
 				// No additional info about this directory
-				directoryTimestamps.set(dir, EXISTANCE_ONLY_TIME_ENTRY);
+				// but maybe another DirectoryWatcher has info
+				if (!directoryTimestamps.has(dir))
+					directoryTimestamps.set(dir, EXISTANCE_ONLY_TIME_ENTRY);
 			}
 			fileTimestamps.set(this.path, EXISTANCE_ONLY_TIME_ENTRY);
 			directoryTimestamps.set(this.path, EXISTANCE_ONLY_TIME_ENTRY);

lib/watchpack.js

@@ -66,7 +66,6 @@ const cachedNormalizeOptions = options => {
 
 class WatchpackFileWatcher {
 	constructor(watchpack, watcher, files) {
-		if (!watcher) throw new Error();
 		this.files = Array.isArray(files) ? files : [files];
 		this.watcher = watcher;
 		watcher.on("initial-missing", type => {
@@ -106,7 +105,6 @@ class WatchpackFileWatcher {
 
 class WatchpackDirectoryWatcher {
 	constructor(watchpack, watcher, directories) {
-		if (!watcher) throw new Error();
 		this.directories = Array.isArray(directories) ? directories : [directories];
 		this.watcher = watcher;
 		watcher.on("initial-missing", type => {