diff --git a/Octokit.Tests/Reactive/ObservableIssuesClientTests.cs b/Octokit.Tests/Reactive/ObservableIssuesClientTests.cs
new file mode 100644
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+++ b/Octokit.Tests/Reactive/ObservableIssuesClientTests.cs
@@ -0,0 +1,364 @@
+using NSubstitute;
+using Octokit.Internal;
+using Octokit.Reactive;
+using Octokit.Tests.Helpers;
+using System;
+using System.Collections.Generic;
+using System.Reactive.Linq;
+using System.Threading.Tasks;
+using Xunit;
+
+namespace Octokit.Tests.Reactive
+{
+    public class ObservableIssuesClientTests
+    {
+        public class TheGetMethod
+        {
+            [Fact]
+            public void GetsFromClientIssueIssue()
+            {
+                var gitHubClient = Substitute.For<IGitHubClient>();
+                var client = new ObservableIssuesClient(gitHubClient);
+
+                client.Get("fake", "repo", 42);
+
+                gitHubClient.Issue.Received().Get("fake", "repo", 42);
+            }
+
+            [Fact]
+            public async Task EnsuresNonNullArguments()
+            {
+                var client = new ObservableIssuesClient(Substitute.For<IGitHubClient>());
+
+                await AssertEx.Throws<ArgumentNullException>(async () => await client.Get(null, "name", 1));
+                await AssertEx.Throws<ArgumentNullException>(async () => await client.Get("owner", null, 1));
+                await AssertEx.Throws<ArgumentException>(async () => await client.Get(null, "", 1));
+                await AssertEx.Throws<ArgumentException>(async () => await client.Get("", null, 1));
+            }
+        }
+
+        public class TheGetForRepositoryMethod
+        {
+            [Fact]
+            public void ReturnsEveryPageOfIssues()
+            {
+                var firstPageUrl = new Uri("repos/fake/repo/issues", UriKind.Relative);
+                var secondPageUrl = new Uri("https://example.com/page/2");
+                var firstPageLinks = new Dictionary<string, Uri> { { "next", secondPageUrl } };
+                var firstPageResponse = new ApiResponse<List<Issue>>
+                {
+                    BodyAsObject = new List<Issue>
+                    {
+                        new Issue {Number = 1},
+                        new Issue {Number = 2},
+                        new Issue {Number = 3},
+                    },
+                    ApiInfo = CreateApiInfo(firstPageLinks)
+                };
+                var thirdPageUrl = new Uri("https://example.com/page/3");
+                var secondPageLinks = new Dictionary<string, Uri> { { "next", thirdPageUrl } };
+                var secondPageResponse = new ApiResponse<List<Issue>>
+                {
+                    BodyAsObject = new List<Issue>
+                    {
+                        new Issue {Number = 4},
+                        new Issue {Number = 5},
+                        new Issue {Number = 6},
+                    },
+                    ApiInfo = CreateApiInfo(secondPageLinks)
+                };
+                var lastPageResponse = new ApiResponse<List<Issue>>
+                {
+                    BodyAsObject = new List<Issue>
+                    {
+                        new Issue {Number = 7},
+                    },
+                    ApiInfo = CreateApiInfo(new Dictionary<string, Uri>())
+                };
+                var gitHubClient = Substitute.For<IGitHubClient>();
+                gitHubClient.Connection.GetAsync<List<Issue>>(Arg.Is(firstPageUrl),
+                    Arg.Is<Dictionary<string, string>>(d => d.Count == 4
+                        && d["direction"] == "desc"
+                        && d["state"] == "open"
+                        && d["sort"] == "created"
+                        && d["filter"] == "assigned"), Arg.Any<string>())
+                    .Returns(Task.Factory.StartNew<IResponse<List<Issue>>>(() => firstPageResponse));
+                gitHubClient.Connection.GetAsync<List<Issue>>(secondPageUrl, null, null)
+                    .Returns(Task.Factory.StartNew<IResponse<List<Issue>>>(() => secondPageResponse));
+                gitHubClient.Connection.GetAsync<List<Issue>>(thirdPageUrl, null, null)
+                    .Returns(Task.Factory.StartNew<IResponse<List<Issue>>>(() => lastPageResponse));
+                var client = new ObservableIssuesClient(gitHubClient);
+
+                var results = client.GetForRepository("fake", "repo").ToArray().Wait();
+
+                Assert.Equal(7, results.Length);
+                Assert.Equal(firstPageResponse.BodyAsObject[0].Number, results[0].Number);
+                Assert.Equal(secondPageResponse.BodyAsObject[1].Number, results[4].Number);
+                Assert.Equal(lastPageResponse.BodyAsObject[0].Number, results[6].Number);
+            }
+        }
+
+        public class TheGetAllForOwnedAndMemberRepositoriesMethod
+        {
+            [Fact]
+            public void ReturnsEveryPageOfIssues()
+            {
+                var firstPageUrl = new Uri("user/issues", UriKind.Relative);
+                var secondPageUrl = new Uri("https://example.com/page/2");
+                var firstPageLinks = new Dictionary<string, Uri> { { "next", secondPageUrl } };
+                var firstPageResponse = new ApiResponse<List<Issue>>
+                {
+                    BodyAsObject = new List<Issue>
+                    {
+                        new Issue {Number = 1},
+                        new Issue {Number = 2},
+                        new Issue {Number = 3},
+                    },
+                    ApiInfo = CreateApiInfo(firstPageLinks)
+                };
+                var thirdPageUrl = new Uri("https://example.com/page/3");
+                var secondPageLinks = new Dictionary<string, Uri> { { "next", thirdPageUrl } };
+                var secondPageResponse = new ApiResponse<List<Issue>>
+                {
+                    BodyAsObject = new List<Issue>
+                    {
+                        new Issue {Number = 4},
+                        new Issue {Number = 5},
+                        new Issue {Number = 6},
+                    },
+                    ApiInfo = CreateApiInfo(secondPageLinks)
+                };
+                var lastPageResponse = new ApiResponse<List<Issue>>
+                {
+                    BodyAsObject = new List<Issue>
+                    {
+                        new Issue {Number = 7},
+                    },
+                    ApiInfo = CreateApiInfo(new Dictionary<string, Uri>())
+                };
+                var gitHubClient = Substitute.For<IGitHubClient>();
+                gitHubClient.Connection.GetAsync<List<Issue>>(Arg.Is(firstPageUrl),
+                    Arg.Is<Dictionary<string, string>>(d => d.Count == 4
+                        && d["direction"] == "desc"
+                        && d["state"] == "open"
+                        && d["sort"] == "created"
+                        && d["filter"] == "assigned"), Arg.Any<string>())
+                    .Returns(Task.Factory.StartNew<IResponse<List<Issue>>>(() => firstPageResponse));
+                gitHubClient.Connection.GetAsync<List<Issue>>(secondPageUrl, null, null)
+                    .Returns(Task.Factory.StartNew<IResponse<List<Issue>>>(() => secondPageResponse));
+                gitHubClient.Connection.GetAsync<List<Issue>>(thirdPageUrl, null, null)
+                    .Returns(Task.Factory.StartNew<IResponse<List<Issue>>>(() => lastPageResponse));
+                var client = new ObservableIssuesClient(gitHubClient);
+
+                var results = client.GetAllForOwnedAndMemberRepositories().ToArray().Wait();
+
+                Assert.Equal(7, results.Length);
+                Assert.Equal(firstPageResponse.BodyAsObject[0].Number, results[0].Number);
+                Assert.Equal(secondPageResponse.BodyAsObject[1].Number, results[4].Number);
+                Assert.Equal(lastPageResponse.BodyAsObject[0].Number, results[6].Number);
+            }
+        }
+
+        public class TheGetAllForOrganizationMethod
+        {
+            [Fact]
+            public void ReturnsEveryPageOfIssues()
+            {
+                var firstPageUrl = new Uri("orgs/test/issues", UriKind.Relative);
+                var secondPageUrl = new Uri("https://example.com/page/2");
+                var firstPageLinks = new Dictionary<string, Uri> { { "next", secondPageUrl } };
+                var firstPageResponse = new ApiResponse<List<Issue>>
+                {
+                    BodyAsObject = new List<Issue>
+                    {
+                        new Issue {Number = 1},
+                        new Issue {Number = 2},
+                        new Issue {Number = 3},
+                    },
+                    ApiInfo = CreateApiInfo(firstPageLinks)
+                };
+                var thirdPageUrl = new Uri("https://example.com/page/3");
+                var secondPageLinks = new Dictionary<string, Uri> { { "next", thirdPageUrl } };
+                var secondPageResponse = new ApiResponse<List<Issue>>
+                {
+                    BodyAsObject = new List<Issue>
+                    {
+                        new Issue {Number = 4},
+                        new Issue {Number = 5},
+                        new Issue {Number = 6},
+                    },
+                    ApiInfo = CreateApiInfo(secondPageLinks)
+                };
+                var lastPageResponse = new ApiResponse<List<Issue>>
+                {
+                    BodyAsObject = new List<Issue>
+                    {
+                        new Issue {Number = 7},
+                    },
+                    ApiInfo = CreateApiInfo(new Dictionary<string, Uri>())
+                };
+                var gitHubClient = Substitute.For<IGitHubClient>();
+                gitHubClient.Connection.GetAsync<List<Issue>>(Arg.Is(firstPageUrl),
+                    Arg.Is<Dictionary<string, string>>(d => d.Count == 4
+                        && d["direction"] == "desc"
+                        && d["state"] == "open"
+                        && d["sort"] == "created"
+                        && d["filter"] == "assigned"), Arg.Any<string>())
+                    .Returns(Task.Factory.StartNew<IResponse<List<Issue>>>(() => firstPageResponse));
+                gitHubClient.Connection.GetAsync<List<Issue>>(secondPageUrl, null, null)
+                    .Returns(Task.Factory.StartNew<IResponse<List<Issue>>>(() => secondPageResponse));
+                gitHubClient.Connection.GetAsync<List<Issue>>(thirdPageUrl, null, null)
+                    .Returns(Task.Factory.StartNew<IResponse<List<Issue>>>(() => lastPageResponse));
+                var client = new ObservableIssuesClient(gitHubClient);
+
+                var results = client.GetAllForOrganization("test").ToArray().Wait();
+
+                Assert.Equal(7, results.Length);
+                Assert.Equal(firstPageResponse.BodyAsObject[0].Number, results[0].Number);
+                Assert.Equal(secondPageResponse.BodyAsObject[1].Number, results[4].Number);
+                Assert.Equal(lastPageResponse.BodyAsObject[0].Number, results[6].Number);
+            }
+        }
+
+        public class TheGetAllForCurrentMethod
+        {
+            [Fact]
+            public void ReturnsEveryPageOfIssues()
+            {
+                var firstPageUrl = new Uri("issues", UriKind.Relative);
+                var secondPageUrl = new Uri("https://example.com/page/2");
+                var firstPageLinks = new Dictionary<string, Uri> { { "next", secondPageUrl } };
+                var firstPageResponse = new ApiResponse<List<Issue>>
+                {
+                    BodyAsObject = new List<Issue>
+                    {
+                        new Issue {Number = 1},
+                        new Issue {Number = 2},
+                        new Issue {Number = 3},
+                    },
+                    ApiInfo = CreateApiInfo(firstPageLinks)
+                };
+                var thirdPageUrl = new Uri("https://example.com/page/3");
+                var secondPageLinks = new Dictionary<string, Uri> { { "next", thirdPageUrl } };
+                var secondPageResponse = new ApiResponse<List<Issue>>
+                {
+                    BodyAsObject = new List<Issue>
+                    {
+                        new Issue {Number = 4},
+                        new Issue {Number = 5},
+                        new Issue {Number = 6},
+                    },
+                    ApiInfo = CreateApiInfo(secondPageLinks)
+                };
+                var lastPageResponse = new ApiResponse<List<Issue>>
+                {
+                    BodyAsObject = new List<Issue>
+                    {
+                        new Issue {Number = 7},
+                    },
+                    ApiInfo = CreateApiInfo(new Dictionary<string, Uri>())
+                };
+                var gitHubClient = Substitute.For<IGitHubClient>();
+                gitHubClient.Connection.GetAsync<List<Issue>>(Arg.Is(firstPageUrl),
+                    Arg.Is<Dictionary<string, string>>(d => d.Count == 4
+                        && d["direction"] == "desc"
+                        && d["state"] == "open"
+                        && d["sort"] == "created"
+                        && d["filter"] == "assigned"), Arg.Any<string>())
+                    .Returns(Task.Factory.StartNew<IResponse<List<Issue>>>(() => firstPageResponse));
+                gitHubClient.Connection.GetAsync<List<Issue>>(secondPageUrl, null, null)
+                    .Returns(Task.Factory.StartNew<IResponse<List<Issue>>>(() => secondPageResponse));
+                gitHubClient.Connection.GetAsync<List<Issue>>(thirdPageUrl, null, null)
+                    .Returns(Task.Factory.StartNew<IResponse<List<Issue>>>(() => lastPageResponse));
+                var client = new ObservableIssuesClient(gitHubClient);
+
+                var results = client.GetAllForCurrent().ToArray().Wait();
+
+                Assert.Equal(7, results.Length);
+                Assert.Equal(firstPageResponse.BodyAsObject[0].Number, results[0].Number);
+                Assert.Equal(secondPageResponse.BodyAsObject[1].Number, results[4].Number);
+                Assert.Equal(lastPageResponse.BodyAsObject[0].Number, results[6].Number);
+            }
+        }
+
+        public class TheCreateMethod
+        {
+            [Fact]
+            public void CreatesFromClientIssueIssue()
+            {
+                var newIssue = new NewIssue("some title");
+                var gitHubClient = Substitute.For<IGitHubClient>();
+                var client = new ObservableIssuesClient(gitHubClient);
+
+                client.Create("fake", "repo", newIssue);
+
+                gitHubClient.Issue.Received().Create("fake", "repo", newIssue);
+            }
+
+            [Fact]
+            public async Task EnsuresArgumentsNotNull()
+            {
+                var gitHubClient = Substitute.For<IGitHubClient>();
+                var client = new ObservableIssuesClient(gitHubClient);
+
+                AssertEx.Throws<ArgumentNullException>(async () => await
+                    client.Create(null, "name", new NewIssue("title")));
+                AssertEx.Throws<ArgumentException>(async () => await
+                    client.Create("", "name", new NewIssue("x")));
+                AssertEx.Throws<ArgumentNullException>(async () => await
+                    client.Create("owner", null, new NewIssue("x")));
+                AssertEx.Throws<ArgumentException>(async () => await
+                    client.Create("owner", "", new NewIssue("x")));
+                AssertEx.Throws<ArgumentNullException>(async () => await
+                    client.Create("owner", "name", null));
+            }
+        }
+
+        public class TheUpdateMethod
+        {
+            [Fact]
+            public void UpdatesClientIssueIssue()
+            {
+                var IssueUpdate = new IssueUpdate();
+                var gitHubClient = Substitute.For<IGitHubClient>();
+                var client = new ObservableIssuesClient(gitHubClient);
+
+                client.Update("fake", "repo", 42, IssueUpdate);
+
+                gitHubClient.Issue.Received().Update("fake", "repo", 42, IssueUpdate);
+            }
+
+            [Fact]
+            public async Task EnsuresArgumentsNotNull()
+            {
+                var gitHubClient = Substitute.For<IGitHubClient>();
+                var client = new ObservableIssuesClient(gitHubClient);
+
+                AssertEx.Throws<ArgumentNullException>(async () => await
+                    client.Create(null, "name", new NewIssue("title")));
+                AssertEx.Throws<ArgumentException>(async () => await
+                    client.Create("", "name", new NewIssue("x")));
+                AssertEx.Throws<ArgumentNullException>(async () => await
+                    client.Create("owner", null, new NewIssue("x")));
+                AssertEx.Throws<ArgumentException>(async () => await
+                    client.Create("owner", "", new NewIssue("x")));
+                AssertEx.Throws<ArgumentNullException>(async () => await
+                    client.Create("owner", "name", null));
+            }
+        }
+
+        public class TheCtor
+        {
+            [Fact]
+            public void EnsuresArgument()
+            {
+                Assert.Throws<ArgumentNullException>(() => new IssuesClient(null));
+            }
+        }
+
+        static ApiInfo CreateApiInfo(IDictionary<string, Uri> links)
+        {
+            return new ApiInfo(links, new List<string>(), new List<string>(), "etag", new RateLimit(new Dictionary<string, string>()));
+        }
+    }
+}