Cloning ApiInfo object should work when some fields are null (#1580)

* Adjust ApiInfo.Clone() to work even if some elements (eg ETag) are null

* Remove c# 6 language feature and do it the old school way

* Add a test for cloning ApiInfo when some fields are null

* The 3 lists can never be null anyway so remove some un-needed statements

* Add test for null RateLimit

Octokit.Tests/Http/ApiInfoTests.cs

@@ -94,6 +94,92 @@ namespace Octokit.Tests.Http
                 Assert.Equal(original.RateLimit.Reset, clone.RateLimit.Reset);
                 Assert.NotSame(original.RateLimit.Reset, clone.RateLimit.Reset);
             }
+
+            [Fact]
+            public void CanCloneWithNullETag()
+            {
+                var original = new ApiInfo(
+                    new Dictionary<string, Uri>
+                    {
+                        {
+                            "next",
+                            new Uri("https://api.github.com/repos/rails/rails/issues?page=4&per_page=5")
+                        },
+                        {
+                            "last",
+                            new Uri("https://api.github.com/repos/rails/rails/issues?page=131&per_page=5")
+                        },
+                        {
+                            "first",
+                            new Uri("https://api.github.com/repos/rails/rails/issues?page=1&per_page=5")
+                        },
+                        {
+                            "prev",
+                            new Uri("https://api.github.com/repos/rails/rails/issues?page=2&per_page=5")
+                        }
+                    },
+                    new List<string>
+                    {
+                        "user"
+                    },
+                    new List<string>(),
+                    null,
+                    new RateLimit(100, 75, 1372700873)
+                );
+
+                var clone = original.Clone();
+
+                Assert.NotNull(clone);
+                Assert.Equal(4, clone.Links.Count);
+                Assert.Equal(1, clone.OauthScopes.Count);
+                Assert.Equal(0, clone.AcceptedOauthScopes.Count);
+                Assert.Null(clone.Etag);
+                Assert.Equal(100, clone.RateLimit.Limit);
+                Assert.Equal(75, clone.RateLimit.Remaining);
+                Assert.Equal(1372700873, clone.RateLimit.ResetAsUtcEpochSeconds);
+            }
+
+            [Fact]
+            public void CanCloneWithNullRateLimit()
+            {
+                var original = new ApiInfo(
+                    new Dictionary<string, Uri>
+                    {
+                        {
+                            "next",
+                            new Uri("https://api.github.com/repos/rails/rails/issues?page=4&per_page=5")
+                        },
+                        {
+                            "last",
+                            new Uri("https://api.github.com/repos/rails/rails/issues?page=131&per_page=5")
+                        },
+                        {
+                            "first",
+                            new Uri("https://api.github.com/repos/rails/rails/issues?page=1&per_page=5")
+                        },
+                        {
+                            "prev",
+                            new Uri("https://api.github.com/repos/rails/rails/issues?page=2&per_page=5")
+                        }
+                    },
+                    new List<string>
+                    {
+                        "user"
+                    },
+                    new List<string>(),
+                    "123abc",
+                    null
+                );
+
+                var clone = original.Clone();
+
+                Assert.NotNull(clone);
+                Assert.Equal(4, clone.Links.Count);
+                Assert.Equal(1, clone.OauthScopes.Count);
+                Assert.Equal(0, clone.AcceptedOauthScopes.Count);
+                Assert.Equal("123abc", clone.Etag);
+                Assert.Null(clone.RateLimit);
+            }
         }
     }
-}
+}

Octokit/Http/ApiInfo.cs

@@ -19,6 +19,7 @@ namespace Octokit
         {
             Ensure.ArgumentNotNull(links, "links");
             Ensure.ArgumentNotNull(oauthScopes, "oauthScopes");
+            Ensure.ArgumentNotNull(acceptedOauthScopes, "acceptedOauthScopes");
 
             Links = new ReadOnlyDictionary<string, Uri>(links);
             OauthScopes = new ReadOnlyCollection<string>(oauthScopes);
@@ -58,16 +59,11 @@ namespace Octokit
         /// <returns>A clone of <seealso cref="ApiInfo"/></returns>
         public ApiInfo Clone()
         {
-            // Seem to have to do this to pass a whole bunch of tests (for example Octokit.Tests.Clients.EventsClientTests.DeserializesCommitCommentEventCorrectly)
-            // I believe this has something to do with the Mocking framework.
-            if (Links == null || OauthScopes == null || RateLimit == null || Etag == null)
-                return null;
-
             return new ApiInfo(Links.Clone(),
-                                OauthScopes.Clone(),
-                                AcceptedOauthScopes.Clone(),
-                                new string(Etag.ToCharArray()),
-                                RateLimit.Clone());
+                               OauthScopes.Clone(),
+                               AcceptedOauthScopes.Clone(),
+                               Etag != null ? new string(Etag.ToCharArray()) : null,
+                               RateLimit != null ? RateLimit.Clone() : null);
         }
     }
 }