feat: support <exclude /> documentation comment

docs/docs/dotnet-api-docs.md

@@ -154,45 +154,18 @@ To disable the default filtering rules, set the `disableDefaultFilter` property
 
 To show private methods, set the `includePrivateMembers` config to `true`. When enabled, internal only langauge keywords such as `private` or `internal` starts to appear in the declaration of all APIs, to accurately reflect API accessibility.
 
-There are two ways of customizing the API filters:
+### The `<exclude />` documentation comment
 
-### Custom with Code
+The `<exclude />` documentation comment excludes the type or member on a per API basis using C# documentation comment:
 
-To use a custom filtering with code:
-
-1. Use docfx .NET API generation as a NuGet library:
-
-```xml
-<PackageReference Include="Docfx.Dotnet" Version="2.62.0" />
-```
-
-2. Configure the filter options:
-
-```cs
-var options = new DotnetApiOptions
-{
-    // Filter based on types
-    IncludeApi = symbol => ...
-
-    // Filter based on attributes
-    IncludeAttribute = symbol => ...
-}
-
-await DotnetApiCatalog.GenerateManagedReferenceYamlFiles("docfx.json", options);
+```csharp
+/// <exclude />
+public class Foo { }
 ```
 
-The filter callbacks takes an [`ISymbol`](https://learn.microsoft.com/en-us/dotnet/api/microsoft.codeanalysis.isymbol?view=roslyn-dotnet) interface and produces an [`SymbolIncludeState`](../api/Docfx.Dotnet.SymbolIncludeState.yml) enum to choose between include the API, exclude the API or use the default filtering behavior.
-
-The callbacks are raised before applying the default rules but after processing type accessibility rules. Private types and members cannot be marked as include unless `includePrivateMembers` is true.
-
-Hiding the parent symbol also hides all of its child symbols, e.g.:
-- If a namespace is hidden, all child namespaces and types underneath it are hidden.
-- If a class is hidden, all nested types underneath it are hidden.
-- If an interface is hidden, explicit implementations of that interface are also hidden.
-
-### Custom with Filter Rules
+### Custom filter rules
 
-To add additional filter rules, add a custom YAML file and set the `filter` property in `docfx.json` to point to the custom YAML filter:
+To bulk filter APIs with custom filter rules, add a custom YAML file and set the `filter` property in `docfx.json` to point to the custom YAML filter:
 
 ```json
 {
@@ -265,3 +238,38 @@ apiRules:
 ```
 
 Where the `ctorArguments` property specifies a list of match conditions based on constructor parameters and the `ctorNamedArguments` property specifies match conditions using named constructor arguments.
+
+
+### Custom code filter
+
+To use a custom filtering with code:
+
+1. Use docfx .NET API generation as a NuGet library:
+
+```xml
+<PackageReference Include="Docfx.Dotnet" Version="2.62.0" />
+```
+
+2. Configure the filter options:
+
+```cs
+var options = new DotnetApiOptions
+{
+    // Filter based on types
+    IncludeApi = symbol => ...
+
+    // Filter based on attributes
+    IncludeAttribute = symbol => ...
+}
+
+await DotnetApiCatalog.GenerateManagedReferenceYamlFiles("docfx.json", options);
+```
+
+The filter callbacks takes an [`ISymbol`](https://learn.microsoft.com/en-us/dotnet/api/microsoft.codeanalysis.isymbol?view=roslyn-dotnet) interface and produces an [`SymbolIncludeState`](../api/Docfx.Dotnet.SymbolIncludeState.yml) enum to choose between include the API, exclude the API or use the default filtering behavior.
+
+The callbacks are raised before applying the default rules but after processing type accessibility rules. Private types and members cannot be marked as include unless `includePrivateMembers` is true.
+
+Hiding the parent symbol also hides all of its child symbols, e.g.:
+- If a namespace is hidden, all child namespaces and types underneath it are hidden.
+- If a class is hidden, all nested types underneath it are hidden.
+- If an interface is hidden, explicit implementations of that interface are also hidden.

src/Docfx.Dotnet/SymbolFilter.cs

@@ -26,24 +26,25 @@ public SymbolFilter(ExtractMetadataConfig config, DotnetApiOptions options)
 
     public bool IncludeApi(ISymbol symbol)
     {
-        return !IsCompilerGeneratedDisplayClass(symbol) && IsSymbolAccessible(symbol) && IncludeApiCore(symbol);
-
-        bool IncludeApiCore(ISymbol symbol)
+        return _cache.GetOrAdd(symbol, _ =>
         {
-            return _cache.GetOrAdd(symbol, _ => _options.IncludeApi?.Invoke(_) switch
-            {
-                SymbolIncludeState.Include => true,
-                SymbolIncludeState.Exclude => false,
-                _ => IncludeApiDefault(symbol),
-            });
-        }
+            return !IsCompilerGeneratedDisplayClass(symbol) &&
+                IsSymbolAccessible(symbol) &&
+                !HasExcludeDocumentComment(symbol) &&
+                _options.IncludeApi?.Invoke(_) switch
+                {
+                    SymbolIncludeState.Include => true,
+                    SymbolIncludeState.Exclude => false,
+                    _ => IncludeApiDefault(symbol),
+                };
+        });
 
         bool IncludeApiDefault(ISymbol symbol)
         {
             if (_filterRule is not null && !_filterRule.CanVisitApi(RoslynFilterData.GetSymbolFilterData(symbol)))
                 return false;
 
-            return symbol.ContainingSymbol is null || IncludeApiCore(symbol.ContainingSymbol);
+            return symbol.ContainingSymbol is null || IncludeApi(symbol.ContainingSymbol);
         }
 
         static bool IsCompilerGeneratedDisplayClass(ISymbol symbol)
@@ -54,24 +55,22 @@ static bool IsCompilerGeneratedDisplayClass(ISymbol symbol)
 
     public bool IncludeAttribute(ISymbol symbol)
     {
-        return IsSymbolAccessible(symbol) && IncludeAttributeCore(symbol);
-
-        bool IncludeAttributeCore(ISymbol symbol)
+        return _attributeCache.GetOrAdd(symbol, _ =>
         {
-            return _attributeCache.GetOrAdd(symbol, _ => _options.IncludeAttribute?.Invoke(_) switch
+            return IsSymbolAccessible(symbol) && !HasExcludeDocumentComment(symbol) && _options.IncludeAttribute?.Invoke(_) switch
             {
                 SymbolIncludeState.Include => true,
                 SymbolIncludeState.Exclude => false,
                 _ => IncludeAttributeDefault(symbol),
-            });
-        }
+            };
+        });
 
         bool IncludeAttributeDefault(ISymbol symbol)
         {
             if (_filterRule is not null && !_filterRule.CanVisitAttribute(RoslynFilterData.GetSymbolFilterData(symbol)))
                 return false;
 
-            return symbol.ContainingSymbol is null || IncludeAttributeCore(symbol.ContainingSymbol);
+            return symbol.ContainingSymbol is null || IncludeAttribute(symbol.ContainingSymbol);
         }
     }
 
@@ -127,4 +126,12 @@ bool IsEiiAndIncludesContainingSymbols(IEnumerable<ISymbol> symbols)
             return symbols.Any() && symbols.All(s => IncludeApi(s.ContainingSymbol));
         }
     }
+
+    private static bool HasExcludeDocumentComment(ISymbol symbol)
+    {
+        return symbol.GetDocumentationCommentXml() is { } xml && (
+            xml.Contains("<exclude/>") ||
+            xml.Contains("<exclude>") ||
+            xml.Contains("<exclude "));
+    }
 }

test/Docfx.Dotnet.Tests/GenerateMetadataFromCSUnitTest.cs

@@ -3709,4 +3709,25 @@ public interface IFoo { void Bar(); }
         Assert.Equal("public class Foo : IFoo", foo.Syntax.Content[SyntaxLanguage.CSharp]);
         Assert.Equal("void IFoo.Bar()", foo.Items[0].Syntax.Content[SyntaxLanguage.CSharp]);
     }
+
+    [Fact]
+    public void TestExcludeDocumentationComment()
+    {
+        var code =
+            """
+            namespace Test
+            {
+                public class Foo
+                {
+                    /// <exclude />
+                    public void F1() {}
+                }
+            }
+            """;
+
+        var output = Verify(code);
+        var foo = output.Items[0].Items[0];
+        Assert.Equal("public class Foo", foo.Syntax.Content[SyntaxLanguage.CSharp]);
+        Assert.Empty(foo.Items);
+    }
 }