Merge branch 'master' of https://github.com/webpack/webpack

Author: sokra

lib/webpack.js

@@ -14,7 +14,7 @@ function webpack(options, callback) {
 		compiler = new MultiCompiler(options.map(function(options) {
 			return webpack(options);
 		}));
-	} else {
+	} else if(typeof options === "object") {
 		new WebpackOptionsDefaulter().process(options);
 
 		compiler = new Compiler();
@@ -23,10 +23,14 @@ function webpack(options, callback) {
 		new NodeEnvironmentPlugin().apply(compiler);
 		compiler.applyPlugins("environment");
 		compiler.applyPlugins("after-environment");
+	} else {
+		throw new Error("Invalid argument: options");
 	}
 	if(callback) {
-		if(options.watch) {
-			return compiler.watch(options.watchDelay, callback);
+		if(typeof callback !== "function") throw new Error("Invalid argument: callback");
+		var watchOptions = options.watch || !Array.isArray(options) ? options : options[0];
+		if(watchOptions.watch) {
+			return compiler.watch(watchOptions.watchDelay, callback);
 		} else {
 			compiler.run(callback);
 		}