Check repository links have an owner and repo name

Author: jcansdale

src/GitHub.App/Services/GitHubContextService.cs

@@ -124,6 +124,18 @@ public GitHubContext FindContextFromUrl(string url)
                 Url = uri
             };
 
+            if (uri.Owner == null)
+            {
+                context.LinkType = LinkType.Unknown;
+                return context;
+            }
+
+            if (uri.RepositoryName == null)
+            {
+                context.LinkType = LinkType.Unknown;
+                return context;
+            }
+
             var repositoryUrl = uri.ToRepositoryUrl().ToString();
             if (string.Equals(url, repositoryUrl, StringComparison.OrdinalIgnoreCase) ||
                 string.Equals(url, repositoryUrl + ".git", StringComparison.OrdinalIgnoreCase))

test/GitHub.App.UnitTests/Services/GitHubContextServiceTests.cs

@@ -137,6 +137,8 @@ public void Url_EqualTo(string url, string expectUrl)
         [TestCase("https://github.com/github/VisualStudio.git", LinkType.Repository)]
         [TestCase("https://github.com/github/VisualStudio/unknown/master/README.md", LinkType.Unknown)]
         [TestCase("https://github.com/github/VisualStudio/blob/master/README.md", LinkType.Blob)]
+        [TestCase("https://github.com", LinkType.Unknown)]
+        [TestCase("https://github.com/github", LinkType.Unknown)]
         [TestCase("https://github.com/github/VisualStudio/unknown/master/README.md", LinkType.Unknown)]
         public void LinkType_EqualTo(string url, LinkType expectLinkType)
         {