workaround throwing in promise mode

Fixes #99

index.js

@@ -256,14 +256,16 @@ function got(url, opts, cb) {
 		opts = {};
 	}
 
-	opts = normalizeArguments(url, opts);
-
 	if (cb) {
-		asCallback(opts, cb);
+		asCallback(normalizeArguments(url, opts), cb);
 		return null;
 	}
 
-	return asPromise(opts);
+	try {
+		return asPromise(normalizeArguments(url, opts));
+	} catch (error) {
+		return Promise.reject(error);
+	}
 }
 
 var helpers = [

test/test-arguments.js

@@ -24,10 +24,15 @@ test('setup', function (t) {
 });
 
 test('url argument is required', function (t) {
+	t.plan(2);
 	t.throws(function () {
-		got();
+		got(undefined, function () {});
 	}, /Parameter `url` must be a string or object, not undefined/);
-	t.end();
+
+	got()
+		.catch(function (err) {
+			t.ok(/Parameter `url` must be a string or object, not undefined/.test(err.message));
+		});
 });
 
 test('accepts url.parse object as first argument', function (t) {

test/test-error.js

@@ -36,10 +36,15 @@ test('dns error message', function (t) {
 });
 
 test('options.body error message', function (t) {
+	t.plan(2);
 	t.throws(function () {
-		got(s.url, {body: function () {}});
+		got(s.url, {body: function () {}}, function () {});
 	}, /options.body must be a ReadableStream, string, Buffer or plain Object/);
-	t.end();
+
+	got(s.url, {body: function () {}})
+		.catch(function (err) {
+			t.ok(/options.body must be a ReadableStream, string, Buffer or plain Object/.test(err.message));
+		});
 });
 
 test('cleanup', function (t) {