Allow empty Virtual Directory

docs/TfsVirtualDirectory/README.md

@@ -0,0 +1,19 @@
+# Virtual Directory
+
+Any version of the server can be configured to use Virtual Directory. By default, Azure DevOps Server 2019 uses empty Virtual Directory (`VirtualDirectory="/"`) while previous versions of the server used `/tfs` as the default.
+
+To find out the value of Virtual Directory for your server check the server configuration as follows:
+
+## Azure DevOps Server 2019 or later
+
+Open _Azure DevOps Server Administration Console_ from start menu and navigate to _Application Tier_. The Virtual Directory is displayed in _Application Tier Summary_ under _Public URL_. It's the part of the URL that follows the server domain ("/VirtualDir" in the example below):
+
+![Azure DevOps Server](AzureDevOpsServer.png)
+
+## Team Foundation Server 2018 or earlier
+
+Open _Team Foundation Server Administration Console_ from start menu and navigate to _Application Tier_. The Virtual Directory is listed in the _Application Tier Summary_:
+
+![Team Foundation Server](TeamFoundationServer.png)
+
+

src/SourceLink.AzureDevOpsServer.Git.UnitTests/GetSourceLinkUrlTests.cs

@@ -28,30 +28,6 @@ public void EmptyHosts()
             Assert.False(result);
         }
 
-        [Fact]
-        public void UnspecifiedVirtualDirectory()
-        {
-            var engine = new MockEngine();
-
-            var task = new GetSourceLinkUrl()
-            {
-                BuildEngine = engine,
-                SourceRoot = new MockItem("/src/", KVP("RepositoryUrl", "http://tfs.com/tfs/zzz"), KVP("SourceControl", "git"), KVP("RevisionId", "0123456789abcdefABCDEF000000000000000000")),
-                Hosts = new[]
-                {
-                    new MockItem("tfs.com", KVP("VirtualDirectory", ""))
-                }
-            };
-
-            bool result = task.Execute();
-
-            // ERROR : Item 'tfs.com' of item group 'SourceLinkAzureDevOpsServerGitHost' must specify metadata 'VirtualDirectory'
-            AssertEx.AssertEqualToleratingWhitespaceDifferences(
-                "ERROR : " + string.Format(CommonResources.ItemOfItemGroupMustSpecifyMetadata, "tfs.com", "SourceLinkAzureDevOpsServerGitHost", "VirtualDirectory"), engine.Log);
-
-            Assert.False(result);
-        }
-
         [Fact]
         public void BadUrl()
         {
@@ -150,6 +126,7 @@ public void BuildSourceLinkUrl(string s1, string s2)
         }
 
         [Theory]
+        [InlineData("", "/")]
         [InlineData("/", "/")]
         [InlineData("a", "/a/")]
         [InlineData("a/", "/a/")]

src/SourceLink.AzureDevOpsServer.Git/GetSourceLinkUrl.cs

@@ -22,12 +22,6 @@ public sealed class GetSourceLinkUrl : GetSourceLinkUrlGitTask
         protected override string BuildSourceLinkUrl(Uri contentUri, Uri gitUri, string relativeUrl, string revisionId, ITaskItem hostItem)
         {
             var virtualDirectory = hostItem.GetMetadata(VirtualDirectoryMetadataName);
-            if (string.IsNullOrEmpty(virtualDirectory))
-            {
-                Log.LogError(CommonResources.ItemOfItemGroupMustSpecifyMetadata, hostItem.ItemSpec, HostsItemGroupName, VirtualDirectoryMetadataName);
-                return null;
-            }
-
             if (!AzureDevOpsUrlParser.TryParseOnPremHttp(relativeUrl, virtualDirectory, out var projectPath, out var repositoryName))
             {
                 Log.LogError(CommonResources.ValueOfWithIdentityIsInvalid, Names.SourceRoot.RepositoryUrlFullName, SourceRoot.ItemSpec, gitUri);