Reduce noisy errors when viewing git diff on VS code (#9407)

* Reduce noise when viewing git diff on VS code

- The language server project was return a wrong file path for uris with git scheme
- e.g. this could happen when opening git diff on VS code

- With this hacky fix, we make up a fake git folder to provide for these file paths
- This makes sure the returned file path for the left hand side of the git diff view,
 would not collide with existing file paths (original file path for the right hand side)

Fixes #9365

* Apply PR feedback and add tests

* Minor fix

src/Razor/src/Microsoft.CodeAnalysis.Razor.Workspaces/UriExtensions.cs

@@ -3,6 +3,7 @@
 
 using System;
 using System.Net;
+using Microsoft.AspNetCore.Razor.Utilities;
 
 namespace Microsoft.CodeAnalysis.Razor;
 
@@ -22,6 +23,27 @@ public static string GetAbsoluteOrUNCPath(this Uri uri)
         }
 
         // Absolute paths are usually encoded.
-        return uri.AbsolutePath.Contains("%") ? WebUtility.UrlDecode(uri.AbsolutePath) : uri.AbsolutePath;
+        var absolutePath = uri.AbsolutePath.Contains("%") ? WebUtility.UrlDecode(uri.AbsolutePath) : uri.AbsolutePath;
+
+        if (string.Equals(uri.Scheme, "git", StringComparison.OrdinalIgnoreCase))
+        {
+            // return a normalized path when we want to add to a fake git directory path (hacky fix for https://github.com/dotnet/razor/issues/9365)
+            return AddToFakeGitDirectoryAtRoot(absolutePath);
+        }
+
+        return absolutePath;
+    }
+
+    private static string AddToFakeGitDirectoryAtRoot(string decodedAbsolutePath)
+    {
+        var normalizedPath = FilePathNormalizer.Normalize(decodedAbsolutePath);
+        var firstSeparatorIndex = normalizedPath.IndexOf('/');
+        if (firstSeparatorIndex < 0)
+        {
+            // no-op
+            return decodedAbsolutePath;
+        }
+
+        return normalizedPath.Insert(firstSeparatorIndex + 1, "_git_/");
     }
 }

src/Razor/test/Microsoft.CodeAnalysis.Razor.Workspaces.Test/UriExtensionsTest.cs

@@ -55,6 +55,41 @@ public void GetAbsoluteOrUNCPath_AbsolutePath_HandlesSpacePaths()
         Assert.Equal("c:/Some/path/to/file path.cshtml", path);
     }
 
+    [OSSkipConditionTheory(new[] { "OSX", "Linux" }), WorkItem("https://github.com/dotnet/razor/issues/9365")]
+    [InlineData(@"git:/c%3A/path/to/dir/Index.cshtml", @"c:/_git_/path/to/dir/Index.cshtml")]
+    [InlineData(@"git:/c:/path%2Fto/dir/Index.cshtml?%7B%22p", @"c:/_git_/path/to/dir/Index.cshtml")]
+    [InlineData(@"git:/c:/path/to/dir/Index.cshtml", @"c:/_git_/path/to/dir/Index.cshtml")]
+    public void GetAbsoluteOrUNCPath_AbsolutePath_HandlesGitScheme(string filePath, string expected)
+    {
+        // Arrange
+        var uri = new Uri(filePath);
+
+        // Act
+        var path = uri.GetAbsoluteOrUNCPath();
+
+        // Assert
+        Assert.Equal(expected, path);
+    }
+
+    [OSSkipConditionTheory(new[] { "OSX", "Linux" })]
+    [InlineData(@"file:///c:/path/to/dir/Index.cshtml", @"c:/path/to/dir/Index.cshtml")]
+    [InlineData(@"file:///c:\path/to\dir/Index.cshtml", @"c:/path/to/dir/Index.cshtml")]
+    [InlineData(@"file:///C:\path\to\dir\Index.cshtml", @"C:/path/to/dir/Index.cshtml")]
+    [InlineData(@"file:///C:\PATH\TO\DIR\Index.cshtml", @"C:/PATH/TO/DIR/Index.cshtml")]
+    [InlineData(@"file:\\path\to\dir\Index.cshtml", @"\\path\to\dir\Index.cshtml")]
+    [InlineData("file:///path/to/dir/Index.cshtml", @"/path/to/dir/Index.cshtml")]
+    public void GetAbsoluteOrUNCPath_AbsolutePath_HandlesFileScheme(string filePath, string expected)
+    {
+        // Arrange
+        var uri = new Uri(filePath);
+
+        // Act
+        var path = uri.GetAbsoluteOrUNCPath();
+
+        // Assert
+        Assert.Equal(expected, path);
+    }
+
     [Fact]
     public void GetAbsoluteOrUNCPath_UNCPath_ReturnsLocalPath()
     {
@@ -93,4 +128,21 @@ public void GetAbsoluteOrUNCPath_UNCPath_HandlesSpacePaths()
         // Assert
         Assert.Equal(@"\\some\path\to\file path.cshtml", path);
     }
+
+    [OSSkipConditionTheory(new[] { "Windows" }), WorkItem("https://github.com/dotnet/razor/issues/9365")]
+    [InlineData("git:///path/to/dir/Index.cshtml", "/_git_/path/to/dir/Index.cshtml")]
+    [InlineData("git:///path%2Fto/dir/Index.cshtml", "/_git_/path/to/dir/Index.cshtml")]
+    [InlineData("file:///path/to/dir/Index.cshtml", @"/path/to/dir/Index.cshtml")]
+    [InlineData("file:///path%2Fto/dir/Index.cshtml", @"/path/to/dir/Index.cshtml")]
+    public void GetAbsoluteOrUNCPath_AbsolutePath_HandlesSchemeProperly(string filePath, string expected)
+    {
+        // Arrange
+        var uri = new Uri(filePath);
+
+        // Act
+        var path = uri.GetAbsoluteOrUNCPath();
+
+        // Assert
+        Assert.Equal(expected, path);
+    }
 }