add unit test for reaction client

Octokit.Tests/Clients/ReactionsClientTests.cs

@@ -0,0 +1,33 @@
+using NSubstitute;
+using System;
+using System.Threading.Tasks;
+using Xunit;
+
+namespace Octokit.Tests.Clients
+{
+    public class ReactionsClientTests
+    {
+        public class TheCtor
+        {
+            [Fact]
+            public void EnsuresNonNullArguments()
+            {
+                Assert.Throws<ArgumentNullException>(() => new ReactionsClient(null));
+            }
+        }
+
+        public class TheDeleteMethod
+        {
+            [Fact]
+            public async Task DeletesCorrectUrl()
+            {
+                var connection = Substitute.For<IApiConnection>();
+                var client = new ReactionsClient(connection);
+
+                await client.Delete(42);
+
+                connection.Received().Delete(Arg.Is<Uri>(u => u.ToString() == "reactions/42"));
+            }
+        }
+    }
+}

Octokit.Tests/Octokit.Tests.csproj

@@ -97,6 +97,7 @@
     <Compile Include="Clients\MergingClientTests.cs" />
     <Compile Include="Clients\OauthClientTests.cs" />
     <Compile Include="Clients\PullRequestReviewCommentReactionsClientTests.cs" />
+    <Compile Include="Clients\ReactionsClientTests.cs" />
     <Compile Include="Clients\RepositoryCommentsClientTests.cs" />
     <Compile Include="Clients\DeploymentsClientTests.cs" />
     <Compile Include="Clients\DeploymentStatusClientTests.cs" />