Improve inheritdoc

Documentation/spec/triple_slash_comments_spec.md

@@ -44,7 +44,7 @@ Custom tags
 -------
 ### inheritdoc
 `docfx` supports a subset of the [inheritdoc functionality available in Sandcastle](https://ewsoftware.github.io/XMLCommentsGuide/html/86453FFB-B978-4A2A-9EB5-70E118CA8073.htm). Specifically, it implements most of the "Top-Level Inheritance Rules". It does not implement:
-* Support for the `cref` or `select` attributes.
+* Support for the `select` attribute.
 * Automatic inheritance of documentation for explicit interface implementations.
 * Support for inline `inheritdoc` tags (i.e., an `inheritdoc` tag inside of an `example` tag).
 

RELEASENOTE.md

@@ -3,6 +3,7 @@ Version Notes (Current Version: v2.49)
 
 v2.49(Pre-release)
 -----------
+1. Add `cref` attribute support (#1306) for inheritdoc and fix copying from templated sources (#1516).
 
 v2.48.1
 -----------

src/Microsoft.DocAsCode.Metadata.ManagedReference.Common/Models/MetadataItem.cs

@@ -157,7 +157,7 @@ public class MetadataItem : ICloneable
 
         [YamlIgnore]
         [JsonIgnore]
-        public bool IsInheritDoc { get; set; }
+        public string InheritDoc { get; set; }
 
         [YamlIgnore]
         [JsonIgnore]

src/Microsoft.DocAsCode.Metadata.ManagedReference.Common/Parsers/TripleSlashCommentModel.cs

@@ -50,7 +50,7 @@ public class TripleSlashCommentModel
 
         public Dictionary<string, string> TypeParameters { get; private set; }
 
-        public bool IsInheritDoc { get; private set; }
+        public string InheritDoc { get; private set; }
 
         private TripleSlashCommentModel(string xml, SyntaxLanguage language, ITripleSlashCommentParserContext context)
         {
@@ -76,7 +76,7 @@ private TripleSlashCommentModel(string xml, SyntaxLanguage language, ITripleSlas
             Examples = GetExamples(nav, context);
             Parameters = GetParameters(nav, context);
             TypeParameters = GetTypeParameters(nav, context);
-            IsInheritDoc = GetIsInheritDoc(nav, context);
+            InheritDoc = GetInheritDoc(nav, context);
         }
 
         public static TripleSlashCommentModel CreateModel(string xml, SyntaxLanguage language, ITripleSlashCommentParserContext context)
@@ -290,22 +290,48 @@ private List<string> GetExamples(XPathNavigator nav, ITripleSlashCommentParserCo
             return GetMultipleExampleNodes(nav, "/member/example").ToList();
         }
 
-        private bool GetIsInheritDoc(XPathNavigator nav, ITripleSlashCommentParserContext context)
+        private string GetInheritDoc(XPathNavigator nav, ITripleSlashCommentParserContext context)
         {
             var node = nav.SelectSingleNode("/member/inheritdoc");
             if (node == null)
             {
-                return false;
+                return null;
             }
+
             if (node.HasAttributes)
             {
-                //The Sandcastle implementation of <inheritdoc /> supports two attributes: 'cref' and 'select'.
-                //These attributes allow changing the source of the inherited doc and controlling what is inherited.
-                //Until these attributes are supported, ignoring inheritdoc elements with attributes, so as not to misinterpret them.
-                Logger.LogWarning("Attributes on <inheritdoc /> elements are not supported; inheritdoc element will be ignored.");
-                return false;
+                // The Sandcastle implementation of <inheritdoc /> supports two attributes: 'cref' and 'select'.
+                // These attributes allow changing the source of the inherited doc and controlling what is inherited.
+                // Only cref is supported currently
+                var cRef = node.GetAttribute("cref", node.NamespaceURI);
+                if (!string.IsNullOrEmpty(cRef))
+                {
+                    // Strict check is needed as value could be an invalid href,
+                    // e.g. !:Dictionary&lt;TKey, string&gt; when user manually changed the intellisensed generic type
+                    var match = CommentIdRegex.Match(cRef);
+                    if (match.Success)
+                    {
+                        var id = match.Groups["id"].Value;
+                        var type = match.Groups["type"].Value;
+
+                        if (type == "Overload")
+                        {
+                            id += '*';
+                        }
+
+                        context.AddReferenceDelegate?.Invoke(id, cRef);
+                        return id;
+                    }
+                }
+                else
+                {
+                    Logger.LogWarning("Unsupported attribute on <inheritdoc />; inheritdoc element will be ignored.");
+                    return null;
+                }
             }
-            return true;
+
+            // Default inheritdoc (no explicit reference)
+            return string.Empty;
         }
 
         private void ResolveCodeSource(XDocument doc, ITripleSlashCommentParserContext context)

src/Microsoft.DocAsCode.Metadata.ManagedReference.FSharp/FSharpCompilation.fs

@@ -674,7 +674,7 @@ type FSharpCompilation (compilation: FSharpCheckProjectResults, projPath: string
                 md.Sees <- cm.Sees
                 md.SeeAlsos <- cm.SeeAlsos
                 md.Examples <- cm.Examples
-                md.IsInheritDoc <- cm.IsInheritDoc
+                md.InheritDoc <- cm.InheritDoc
                 if not (isNull md.Syntax) then
                     if not (isNull md.Syntax.Parameters) then
                         for pmd in md.Syntax.Parameters do

src/Microsoft.DocAsCode.Metadata.ManagedReference.Roslyn/Visitors/VisitorHelper.cs

@@ -33,7 +33,7 @@ public static void FeedComments(MetadataItem item, ITripleSlashCommentParserCont
                 item.Sees = commentModel.Sees;
                 item.SeeAlsos = commentModel.SeeAlsos;
                 item.Examples = commentModel.Examples;
-                item.IsInheritDoc = commentModel.IsInheritDoc;
+                item.InheritDoc = commentModel.InheritDoc;
                 item.CommentModel = commentModel;
             }
         }

src/Microsoft.DocAsCode.Metadata.ManagedReference/MergeComments/MergeCommentsHelper.cs

@@ -179,7 +179,7 @@ private static void PatchViewModel(MetadataItem item, string comment)
                     }
                 }
             }
-            item.IsInheritDoc = commentModel.IsInheritDoc;
+            item.InheritDoc = commentModel.InheritDoc;
             // todo more.
         }
 

src/Microsoft.DocAsCode.Metadata.ManagedReference/Resolvers/CopyInheritedDocumentation.cs

@@ -21,18 +21,17 @@ public void Run(MetadataModel yaml, ResolverContext context)
                 s => s.IsInvalid ? null : s.Items,
                 (current, parent) =>
                 {
-                    if (current.IsInheritDoc)
+                    if (current.InheritDoc != null)
                     {
                         InheritDoc(current, context);
+                        current.InheritDoc = null;
                     }
                     return true;
                 });
         }
 
         private static void InheritDoc(MetadataItem dest, ResolverContext context)
         {
-            dest.IsInheritDoc = false;
-
             switch (dest.Type)
             {
                 case MemberType.Constructor:
@@ -126,22 +125,37 @@ private static void InheritDoc(MetadataItem dest, ResolverContext context)
 
         private static void Copy(MetadataItem dest, string srcName, ResolverContext context)
         {
-            if (string.IsNullOrEmpty(srcName) || !context.Members.TryGetValue(srcName, out MetadataItem src))
+            MetadataItem src = null;
+
+            // An explicit <inheritdoc/> (i.e. cref) overrides the default behavior
+            if (!string.IsNullOrEmpty(dest.InheritDoc) && context.Members.TryGetValue(dest.InheritDoc, out src))
             {
+                srcName = dest.InheritDoc;
+            }
+
+            if (string.IsNullOrEmpty(srcName))
                 return;
+
+            if (src == null && !context.Members.TryGetValue(srcName, out src))
+            {
+                // Try to resolve any templated references before giving up
+                if (!context.References.TryGetValue(srcName, out var referenceItem) || !context.Members.TryGetValue(referenceItem.Definition, out src))
+                    return;
             }
 
             Copy(dest, src, context);
         }
 
         private static void Copy(MetadataItem dest, MetadataItem src, ResolverContext context)
         {
-            if (src.IsInheritDoc)
+            if (src.InheritDoc != null)
             {
                 InheritDoc(src, context);
+                src.InheritDoc = null;
             }
 
             dest.CopyInheritedData(src);
+            dest.InheritDoc = null;
         }
     }
 }

test/Microsoft.DocAsCode.Metadata.ManagedReference.Tests/TripleSlashParserUnitTest.cs

@@ -44,7 +44,7 @@ public int Main(string[] args)
             string input = @"
 <member name='T:TestClass1.Partial1'>
     <summary>
-        Parital classes <see cref='T:System.AccessViolationException'/><see cref='T:System.AccessViolationException'/>can not cross assemblies, Test <see langword='null'/>
+        Partial classes <see cref='T:System.AccessViolationException'/><see cref='T:System.AccessViolationException'/>can not cross assemblies, Test <see langword='null'/>
 
         ```
         Classes in assemblies are by definition complete.
@@ -134,11 +134,11 @@ Check empty code.
             };
 
             var commentModel = TripleSlashCommentModel.CreateModel(input, SyntaxLanguage.CSharp, context);
-            Assert.False(commentModel.IsInheritDoc, nameof(commentModel.IsInheritDoc));
+            Assert.True(commentModel.InheritDoc == null, nameof(commentModel.InheritDoc));
 
             var summary = commentModel.Summary;
             Assert.Equal(@"
-Parital classes <xref href=""System.AccessViolationException"" data-throw-if-not-resolved=""false""></xref><xref href=""System.AccessViolationException"" data-throw-if-not-resolved=""false""></xref>can not cross assemblies, Test <xref uid=""langword_csharp_null"" name=""null"" href=""""></xref>
+Partial classes <xref href=""System.AccessViolationException"" data-throw-if-not-resolved=""false""></xref><xref href=""System.AccessViolationException"" data-throw-if-not-resolved=""false""></xref>can not cross assemblies, Test <xref uid=""langword_csharp_null"" name=""null"" href=""""></xref>
 
 ```
 Classes in assemblies are by definition complete.
@@ -242,7 +242,25 @@ public void InheritDoc()
             };
 
             var commentModel = TripleSlashCommentModel.CreateModel(input, SyntaxLanguage.CSharp, context);
-            Assert.True(commentModel.IsInheritDoc);
+            Assert.True(commentModel.InheritDoc != null, nameof(commentModel.InheritDoc));
+        }
+
+        [Trait("Related", "TripleSlashComments")]
+        [Fact]
+        public void InheritDocWithCref()
+        {
+            const string input = @"
+<member name=""M:ClassLibrary1.MyClass.DoThing"">
+    <inheritdoc cref=""M:ClassLibrary1.MyClass.DoThing""/>
+</member>";
+            var context = new TripleSlashCommentParserContext
+            {
+                AddReferenceDelegate = null,
+                PreserveRawInlineComments = false,
+            };
+
+            var commentModel = TripleSlashCommentModel.CreateModel(input, SyntaxLanguage.CSharp, context);
+            Assert.Equal("ClassLibrary1.MyClass.DoThing", commentModel.InheritDoc);
         }
 
         [Trait("Related", "TripleSlashComments")]