chore: Add snapshot tests support that are executed on forked repository

src/Docfx.Common/Git/GitUtility.cs

@@ -2,6 +2,7 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 
 using System.Collections.Concurrent;
+using System.Diagnostics;
 using System.Text.RegularExpressions;
 using Docfx.Plugins;
 
@@ -38,9 +39,13 @@ record Repo(string path, string url, string branch);
         if (repo is null)
             return null;
 
+        var repoUrl = EnvironmentContext.IsSnapshotTestContext
+            ? RewritePathForSnapshotTest(repo.url)
+            : repo.url;
+
         return new()
         {
-            Repo = repo.url,
+            Repo = repoUrl,
             Branch = repo.branch,
             Path = Path.GetRelativePath(repo.path, filePath).Replace('\\', '/'),
         };
@@ -49,10 +54,14 @@ record Repo(string path, string url, string branch);
     public static string? RawContentUrlToContentUrl(string rawUrl)
     {
         // GitHub
-        return Regex.Replace(
+        var url = Regex.Replace(
             rawUrl,
             @"^https://raw\.githubusercontent\.com/([^/]+)/([^/]+)/([^/]+)/(.+)$",
             string.IsNullOrEmpty(s_branch) ? "/~https://github.com/$1/$2/blob/$3/$4" : $"/~https://github.com/$1/$2/blob/{s_branch}/$4");
+
+        return EnvironmentContext.IsSnapshotTestContext
+            ? RewritePathForSnapshotTest(url)
+            : url;
     }
 
     public static string? GetSourceUrl(GitSource source)
@@ -65,7 +74,7 @@ record Repo(string path, string url, string branch);
 
         var path = source.Path.Replace('\\', '/');
 
-        return url.Host switch
+        var sourceUrl = url.Host switch
         {
             "github.com" => $"https://github.com{url.AbsolutePath}/blob/{source.Branch}/{path}{(source.Line > 0 ? $"#L{source.Line}" : null)}",
             "bitbucket.org" => $"https://bitbucket.org{url.AbsolutePath}/src/{source.Branch}/{path}{(source.Line > 0 ? $"#lines-{source.Line}" : null)}",
@@ -74,6 +83,13 @@ _ when url.Host.EndsWith(".visualstudio.com") || url.Host == "dev.azure.com" =>
             _ => null,
         };
 
+        if (sourceUrl == null)
+            return null;
+
+        return EnvironmentContext.IsSnapshotTestContext
+            ? RewritePathForSnapshotTest(sourceUrl)
+            : sourceUrl;
+
         static bool IsCommit(string branch)
         {
             return branch.Length == 40 && branch.All(char.IsLetterOrDigit);
@@ -173,4 +189,15 @@ static string GitUrlToHttps(string url)
             }
         }
     }
+
+    private static string RewritePathForSnapshotTest(string path)
+    {
+        Debug.Assert(EnvironmentContext.IsSnapshotTestContext);
+
+        // Remove trailing `.git`.
+        path = path.TrimEnd(".git");
+
+        // Replace `/{organization}/docfx` path to `/dotnet/docfx`.
+        return Regex.Replace(path, @"/[^/]+/docfx", $"/dotnet/docfx");
+    }
 }

src/Docfx.Plugins/EnvironmentContext.cs

@@ -56,4 +56,19 @@ public static void Clean()
         _outputDirectory = null;
         FileAbstractLayerImpl = null;
     }
+
+    /// <summary>
+    /// Gets whether the current docfx process is running snapshot tests.
+    /// </summary>
+    [EditorBrowsable(EditorBrowsableState.Never)]
+    public static bool IsSnapshotTestContext
+    {
+        get { return _isSnapshotTestContext.Value; }
+        set { _isSnapshotTestContext = new Lazy<bool>(() => value); }
+    }
+
+    private static Lazy<bool> _isSnapshotTestContext = new Lazy<bool>(() =>
+    {
+        return Environment.GetEnvironmentVariable("DOCFX_IS_SNAPSHOT_TEST_CONTEXT") != null;
+    });
 }

test/docfx.Snapshot.Tests/SamplesTest.cs

@@ -8,17 +8,34 @@
 using System.Text.Json.Nodes;
 using System.Text.Json.Serialization;
 using Docfx.Dotnet;
+using Docfx.Plugins;
 using UglyToad.PdfPig;
 using UglyToad.PdfPig.Actions;
 using UglyToad.PdfPig.Annotations;
 using UglyToad.PdfPig.Outline;
 
 namespace Docfx.Tests;
 
-public class SamplesTest
+[Collection("docfx STA")]
+[Trait("Stage", "Snapshot")]
+public class SamplesTest : IDisposable
 {
     private static readonly string s_samplesDir = Path.GetFullPath("../../../../../samples");
 
+    private const string DOCFX_IS_SNAPSHOT_TEST_CONTEXT = nameof(DOCFX_IS_SNAPSHOT_TEST_CONTEXT);
+
+    public SamplesTest()
+    {
+        EnvironmentContext.IsSnapshotTestContext = true; // Used for tests that are executed in-process.
+        Environment.SetEnvironmentVariable(DOCFX_IS_SNAPSHOT_TEST_CONTEXT, "true"); // Used for tests that launch child process.
+    }
+
+    public void Dispose()
+    {
+        EnvironmentContext.IsSnapshotTestContext = false;
+        Environment.SetEnvironmentVariable(DOCFX_IS_SNAPSHOT_TEST_CONTEXT, null);
+    }
+
     private class SamplesFactAttribute : FactAttribute
     {
         public SamplesFactAttribute()

test/docfx.Tests/Api.verified.cs

@@ -3950,6 +3950,7 @@ public static class EnvironmentContext
         public static bool GitFeaturesDisabled { get; }
         public static string OutputDirectory { get; }
         public static Docfx.Plugins.IFileAbstractLayer FileAbstractLayerImpl { get; set; }
+        public static bool IsSnapshotTestContext { get; set; }
         public static void Clean() { }
         public static void SetBaseDirectory(string dir) { }
         public static void SetGitFeaturesDisabled(bool disabled) { }