From 2b1f8af5a333554a55aafe9a8031d5cc1a7e9814 Mon Sep 17 00:00:00 2001
From: daver32 <38791383+daver32@users.noreply.github.com>
Date: Sun, 15 Aug 2021 14:41:36 +0200
Subject: [PATCH] added support for records

---
 .../RecordInterfaceGenerationTests.cs         | 54 +++++++++++++++++++
 InterfaceGenerator/AutoInterfaceGenerator.cs  | 17 +++---
 InterfaceGenerator/SyntaxReceiver.cs          | 14 +++--
 3 files changed, 75 insertions(+), 10 deletions(-)
 create mode 100644 InterfaceGenerator.Tests/RecordInterfaceGenerationTests.cs

diff --git a/InterfaceGenerator.Tests/RecordInterfaceGenerationTests.cs b/InterfaceGenerator.Tests/RecordInterfaceGenerationTests.cs
new file mode 100644
index 0000000..d300119
--- /dev/null
+++ b/InterfaceGenerator.Tests/RecordInterfaceGenerationTests.cs
@@ -0,0 +1,54 @@
+using System.Runtime.CompilerServices;
+using FluentAssertions;
+using Xunit;
+
+namespace InterfaceGenerator.Tests
+{
+    public class RecordInterfaceGenerationTests
+    {
+        private readonly ITestRecord _sut;
+
+        public RecordInterfaceGenerationTests()
+        {
+            _sut = new TestRecord(420);
+        }
+
+        [Fact]
+        public void RecordProperty_IsGenerated()
+        {
+            var prop = typeof(ITestRecord)
+                .GetProperty(nameof(TestRecord.RecordProperty));
+
+            prop.Should().NotBeNull();
+
+            prop.GetMethod.Should().NotBeNull();
+            prop.SetMethod.Should().NotBeNull();
+            prop.SetMethod.ReturnParameter.GetRequiredCustomModifiers().Should().Contain(typeof(IsExternalInit));
+
+            _sut.RecordProperty.Should().Be(420);
+        }
+
+        [Fact]
+        public void RecordMethod_IsGenerated()
+        {
+            var method = typeof(ITestRecord).GetMethod(
+                nameof(TestRecord.RecordMethod));
+
+            method.Should().NotBeNull();
+            method.ReturnType.Should().Be(typeof(void));
+
+            var parameters = method.GetParameters();
+            parameters.Should().BeEmpty();
+
+            _sut.RecordMethod();
+        }
+    }
+
+    [GenerateAutoInterface]
+    internal record TestRecord(int RecordProperty) : ITestRecord
+    {
+        public void RecordMethod()
+        {
+        }
+    }
+}
\ No newline at end of file
diff --git a/InterfaceGenerator/AutoInterfaceGenerator.cs b/InterfaceGenerator/AutoInterfaceGenerator.cs
index f3ddd0d..056602a 100644
--- a/InterfaceGenerator/AutoInterfaceGenerator.cs
+++ b/InterfaceGenerator/AutoInterfaceGenerator.cs
@@ -236,7 +236,6 @@ namespace InterfaceGenerator
             if (propertySymbol.IsIndexer)
             {
                 writer.Write("{0} this[", propertySymbol.Type);
-                //writer.WriteJoin(", ", propertySymbol.Parameters, (w, param) => { w.Write("{0} {1}", param.Type, param.Name); });
                 writer.WriteJoin(", ", propertySymbol.Parameters, WriteMethodParam);
                 writer.Write("] ");
             }
@@ -273,6 +272,12 @@ namespace InterfaceGenerator
             {
                 return;
             }
+
+            if (methodSymbol.IsImplicitlyDeclared) 
+            {
+                // omit methods that are auto generated by the compiler (eg. record's methods)
+                return;
+            }
             
             WriteMemberDocs(writer, methodSymbol);
 
@@ -386,14 +391,14 @@ namespace InterfaceGenerator
 
         private static IEnumerable<INamedTypeSymbol> GetImplTypeSymbols(Compilation compilation, SyntaxReceiver receiver)
         {
-            return receiver.CandidateClasses.Select(candidate => GetClassSymbol(compilation, candidate));
+            return receiver.CandidateTypes.Select(candidate => GetTypeSymbol(compilation, candidate));
         }
 
-        private static INamedTypeSymbol GetClassSymbol(Compilation compilation, ClassDeclarationSyntax @class)
+        private static INamedTypeSymbol GetTypeSymbol(Compilation compilation, TypeDeclarationSyntax type)
         {
-            var model = compilation.GetSemanticModel(@class.SyntaxTree);
-            var classSymbol = ModelExtensions.GetDeclaredSymbol(model, @class)!;
-            return (INamedTypeSymbol)classSymbol;
+            var model = compilation.GetSemanticModel(type.SyntaxTree);
+            var typeSymbol = ModelExtensions.GetDeclaredSymbol(model, type)!;
+            return (INamedTypeSymbol)typeSymbol;
         }
 
         private static Compilation GetCompilation(GeneratorExecutionContext context)
diff --git a/InterfaceGenerator/SyntaxReceiver.cs b/InterfaceGenerator/SyntaxReceiver.cs
index 7ca7f04..570b42b 100644
--- a/InterfaceGenerator/SyntaxReceiver.cs
+++ b/InterfaceGenerator/SyntaxReceiver.cs
@@ -6,15 +6,21 @@ namespace InterfaceGenerator
 {
     internal class SyntaxReceiver : ISyntaxReceiver
     {
-        public IList<ClassDeclarationSyntax> CandidateClasses { get; } = new List<ClassDeclarationSyntax>();
+        public IList<TypeDeclarationSyntax> CandidateTypes { get; } = new List<TypeDeclarationSyntax>();
         
         public void OnVisitSyntaxNode(SyntaxNode syntaxNode)
         {
-            if (syntaxNode is ClassDeclarationSyntax classDeclarationSyntax &&
-                classDeclarationSyntax.AttributeLists.Count > 0)
+            if (syntaxNode is TypeDeclarationSyntax typeDeclarationSyntax &&
+                IsClassOrRecord(typeDeclarationSyntax) &&
+                typeDeclarationSyntax.AttributeLists.Count > 0)
             {
-                CandidateClasses.Add(classDeclarationSyntax);
+                CandidateTypes.Add(typeDeclarationSyntax);
             }
         }
+
+        private static bool IsClassOrRecord(TypeDeclarationSyntax typeDeclarationSyntax)
+        {
+            return typeDeclarationSyntax is ClassDeclarationSyntax || typeDeclarationSyntax is RecordDeclarationSyntax;
+        }
     }
 }
\ No newline at end of file