npm and error messages

node_modules/enhanced-resolve/lib/FileExistsPlugin.js

@@ -0,0 +1,30 @@
+/*
+	MIT License http://www.opensource.org/licenses/mit-license.php
+	Author Tobias Koppers @sokra
+*/
+function FileExistsPlugin(source, target) {
+	this.source = source;
+	this.target = target;
+}
+module.exports = FileExistsPlugin;
+
+FileExistsPlugin.prototype.apply = function(resolver) {
+	var target = this.target;
+	resolver.plugin(this.source, function(request, callback) {
+		var fs = this.fileSystem;
+		var file = request.path;
+		fs.stat(file, function(err, stat) {
+			if(err || !stat) {
+				if(callback.missing) callback.missing.push(file);
+				if(callback.log) callback.log(file + " doesn't exist");
+				return callback();
+			}
+			if(!stat.isFile()) {
+				if(callback.missing) callback.missing.push(file);
+				if(callback.log) callback.log(file + " is not a file");
+				return callback();
+			}
+			this.doResolve(target, request, "existing file: " + file, callback, true);
+		}.bind(this));
+	});
+};