Align on backslashes

Co-authored-by: John L. Armstrong IV <[email protected]>

Author: chelkyl

src/Microsoft.OpenApi/Services/OpenApiUrlTreeNode.cs

@@ -155,7 +155,7 @@ public OpenApiUrlTreeNode Attach(string path,
                 // Remove the last element, which is empty, and append the trailing slash to the new last element
                 // This is to support URLs with trailing slashes
                 Array.Resize(ref segments, segments.Length - 1);
-                segments[segments.Length - 1] += "/";
+                segments[segments.Length - 1] += @"\";
             }
 
             return Attach(segments: segments,

test/Microsoft.OpenApi.Tests/Services/OpenApiUrlTreeNodeTests.cs

@@ -470,8 +470,8 @@ public async Task VerifyDiagramFromSampleOpenAPI()
         public static TheoryData<string, string[], string, string> SupportsTrailingSlashesInPathData => new TheoryData<string, string[], string, string>
         {
             // Path, children up to second to leaf, last expected leaf node name, expected leaf node path
-            { "/cars/{car-id}/build/", ["cars", "{car-id}"], "build/", @"\cars\{car-id}\build/" },
-            { "/cars/", [], "cars/", @"\cars/" },
+            { "/cars/{car-id}/build/", ["cars", "{car-id}"], @"build\", @"\cars\{car-id}\build\" },
+            { "/cars/", [], @"cars\", @"\cars\" },
         };
 
         [Theory]