Index: Src/GoogleApis.Auth.Tests/OAuth2/Requests/AuthorizationCodeRequestUrlTests.cs
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new file mode 100644
--- /dev/null
+++ b/Src/GoogleApis.Auth.Tests/OAuth2/Requests/AuthorizationCodeRequestUrlTests.cs
@@ -0,0 +1,82 @@
+/*
+Copyright 2013 Google Inc
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+using System;
+
+using NUnit.Framework;
+
+namespace Google.Apis.Auth.OAuth2.Requests
+{
+    /// <summary>
+    /// Tests for <seealso cref="Google.Apis.Auth.OAuth2.Requests.AuthorizationCodeRequestUrl"/>. 
+    /// It tests that the constructor sets the default values and the building URI method.
+    /// </summary>
+    [TestFixture]
+    public class AuthorizationCodeRequestUrlTests
+    {
+        private readonly Uri AuthorizationCodeUrl = new Uri("http://www.authorization-server.com");
+
+        [Test]
+        public void TestConstructor()
+        {
+            var request = new AuthorizationCodeRequestUrl(AuthorizationCodeUrl);
+            Assert.That(request.AuthorizationServerUrl, Is.EqualTo(AuthorizationCodeUrl));
+            Assert.Null(request.ClientId);
+            Assert.Null(request.RedirectUri);
+            Assert.That(request.ResponseType, Is.EqualTo("code"));
+            Assert.Null(request.Scope);
+            Assert.Null(request.State);
+        }
+
+        [Test]
+        public void TestBuild_DefaultValues()
+        {
+            var request = new AuthorizationCodeRequestUrl(AuthorizationCodeUrl);
+            var uri = request.Build();
+            Assert.That(uri, Is.EqualTo(new Uri(AuthorizationCodeUrl.ToString() + "?response_type=code")));
+        }
+
+        [Test]
+        public void TestBuild()
+        {
+            var request = new AuthorizationCodeRequestUrl(AuthorizationCodeUrl)
+            {
+                ClientId = "100",
+                RedirectUri = "200",
+                Scope = "SCOPE",
+                State = "state",
+            };
+            var uri = request.Build();
+            Assert.That(uri, Is.EqualTo(new Uri(AuthorizationCodeUrl.ToString() +
+                "?response_type=code&client_id=100&redirect_uri=200&scope=SCOPE&state=state")));
+        }
+
+        [Test]
+        public void TestBuild_EscapeValues()
+        {
+            var request = new AuthorizationCodeRequestUrl(AuthorizationCodeUrl)
+            {
+                ClientId = "pa$$word",
+                RedirectUri = "???",
+                Scope = "SC@PE",
+                State = "!",
+            };
+            var uri = request.Build();
+            Assert.That(uri, Is.EqualTo(new Uri(AuthorizationCodeUrl.ToString() +
+                "?response_type=code&client_id=pa%24%24word&redirect_uri=%3F%3F%3F&scope=SC%40PE&state=%21")));
+        }
+    }
+}