fix: Xrefmap baseUrl problem reported at #9866

src/Docfx.Build/XRefMaps/XRefArchiveBuilder.cs

@@ -47,16 +47,6 @@ private async Task<string> DownloadCoreAsync(Uri uri, XRefArchive xa)
             return null;
         }
 
-        // If BaseUrl is not set. Use xrefmap file download url as basePath.
-        if (string.IsNullOrEmpty(map.BaseUrl))
-        {
-            var baseUrl = uri.GetLeftPart(UriPartial.Path);
-            baseUrl = baseUrl.Substring(0, baseUrl.LastIndexOf('/') + 1);
-            map.BaseUrl = baseUrl;
-            map.UpdateHref(new Uri(baseUrl)); // Update hrefs from relative to absolute url.
-            map.HrefUpdated = null; // Don't save this flag for downloaded XRefMap.
-        }
-
         // Enforce XRefMap's references are sorted by uid.
         // Note:
         //   Sort is not needed if `map.Sorted == true`.

src/Docfx.Build/XRefMaps/XRefMapDownloader.cs

@@ -1,6 +1,8 @@
 // Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
 
+using System;
+using System.Diagnostics;
 using System.Net;
 using Docfx.Common;
 
@@ -152,33 +154,29 @@ protected static async Task<XRefMap> DownloadFromWebAsync(Uri uri)
             case ".json":
                 {
                     using var sr = new StreamReader(stream, bufferSize: 81920); // Default :1024 byte
-                    return JsonUtility.Deserialize<XRefMap>(sr);
+                    var xrefMap = JsonUtility.Deserialize<XRefMap>(sr);
+                    xrefMap.BaseUrl = ResolveBaseUrl(xrefMap, uri);
+                    return xrefMap;
                 }
             case ".yml":
             default:
                 {
                     using var sr = new StreamReader(stream, bufferSize: 81920); // Default :1024 byte
-                    return YamlUtility.Deserialize<XRefMap>(sr);
+                    var xrefMap = YamlUtility.Deserialize<XRefMap>(sr);
+                    xrefMap.BaseUrl = ResolveBaseUrl(xrefMap, uri);
+                    return xrefMap;
                 }
         }
     }
 
-    public static void UpdateHref(XRefMap map, Uri uri)
+    private static string ResolveBaseUrl(XRefMap map, Uri uri)
     {
         if (!string.IsNullOrEmpty(map.BaseUrl))
-        {
-            if (!Uri.TryCreate(map.BaseUrl, UriKind.Absolute, out Uri baseUri))
-            {
-                throw new InvalidDataException($"Xref map file (from {uri.AbsoluteUri}) has an invalid base url: {map.BaseUrl}.");
-            }
-            map.UpdateHref(baseUri);
-            return;
-        }
-        if (uri.Scheme == "http" || uri.Scheme == "https")
-        {
-            map.UpdateHref(uri);
-            return;
-        }
-        throw new InvalidDataException($"Xref map file (from {uri.AbsoluteUri}) missing base url.");
+            return map.BaseUrl;
+
+        // If downloaded xrefmap has no baseUrl.
+        // Use xrefmap file download url as basePath.
+        var baseUrl = uri.GetLeftPart(UriPartial.Path);
+        return baseUrl.Substring(0, baseUrl.LastIndexOf('/') + 1);
     }
 }

test/Docfx.Build.Tests/XRefMapDownloaderTest.cs

@@ -50,4 +50,58 @@ public async Task ReadLocalXRefMapJsonFileTest()
         xrefMap.Should().NotBeNull();
         xrefMap.References.Should().HaveCount(1);
     }
+
+    /// <summary>
+    /// XrefmapDownloader test for xrefmap that has no baseUrl and href is defined by relative path.
+    /// </summary>
+    [Fact(Skip = "Has dependency to external site content.")]
+    public async Task ReadRemoteXRefMapYamlFileTest1()
+    {
+        // Arrange
+        var path = "https://horizongir.github.io/ZedGraph/xrefmap.yml";
+
+        XRefMapDownloader downloader = new XRefMapDownloader();
+        var xrefMap = await downloader.DownloadAsync(new Uri(path)) as XRefMap;
+
+        // Assert
+        xrefMap.Sorted.Should().BeTrue();
+        xrefMap.HrefUpdated.Should().BeNull();
+
+        // If baseUrl is not exists. Set download URL is set automatically.
+        xrefMap.BaseUrl.Should().Be("https://horizongir.github.io/ZedGraph/");
+
+        // Test relative URL is preserved.
+        xrefMap.References[0].Href.Should().Be("api/ZedGraph.html");
+        xrefMap.References[0].Href = "https://horizongir.github.io/ZedGraph/api/ZedGraph.html";
+        xrefMap.BaseUrl = "http://localhost";
+
+        // Test url is resolved as absolute URL.
+        var reader = xrefMap.GetReader();
+        reader.Find("ZedGraph").Href.Should().Be("https://horizongir.github.io/ZedGraph/api/ZedGraph.html");
+    }
+
+    /// <summary>
+    /// XrefmapDownloader test for xrefmap that has no baseUrl, and href is defined by absolute path.
+    /// </summary>
+    [Fact(Skip = "Has dependency to external site content.")]
+    public async Task ReadRemoteXRefMapJsonFileTest2()
+    {
+        // Arrange
+        var path = "https://normanderwan.github.io/UnityXrefMaps/xrefmap.yml";
+
+        XRefMapDownloader downloader = new XRefMapDownloader();
+        var xrefMap = await downloader.DownloadAsync(new Uri(path)) as XRefMap;
+
+        // Assert
+        xrefMap.Sorted.Should().BeTrue();
+        xrefMap.HrefUpdated.Should().BeNull();
+
+        // If baseUrl is not exists. XrefMap download URL is set automatically.
+        xrefMap.BaseUrl.Should().Be("https://normanderwan.github.io/UnityXrefMaps/");
+
+        // If href is absolute URL. baseURL is ignored.
+        var xrefSpec = xrefMap.References[0];
+        xrefSpec.Href.Should().Be("https://docs.unity3d.com/ScriptReference/index.html");
+        xrefMap.GetReader().Find(xrefSpec.Uid).Href.Should().Be("https://docs.unity3d.com/ScriptReference/index.html");
+    }
 }

test/docfx.Tests/Api.verified.cs

@@ -476,7 +476,6 @@ public XRefMapDownloader(string baseFolder = null, System.Collections.Generic.IR
         protected virtual System.Threading.Tasks.Task<Docfx.Build.Engine.IXRefContainer> DownloadBySchemeAsync(System.Uri uri) { }
         protected static Docfx.Build.Engine.IXRefContainer DownloadFromLocal(System.Uri uri) { }
         protected static System.Threading.Tasks.Task<Docfx.Build.Engine.XRefMap> DownloadFromWebAsync(System.Uri uri) { }
-        public static void UpdateHref(Docfx.Build.Engine.XRefMap map, System.Uri uri) { }
     }
     public sealed class XRefMapReader : Docfx.Build.Engine.XRefRedirectionReader
     {