From 0ea1232380e803f9480800605edc21f18c14e5c6 Mon Sep 17 00:00:00 2001
From: Jake Soenneker <jake@soenneker.com>
Date: Wed, 20 Nov 2024 14:59:03 -0600
Subject: [PATCH] Protects against top level type generation of delegates

---
 src/Generators/Types/TypeGenerator.cs         |  8 +++++
 .../AutoFakerTests.cs                         | 35 +++++++++++++++++++
 .../Simple/TestClassWithAutoPropertyAction.cs |  9 +++++
 .../Simple/TestClassWithAutoPropertyFunc.cs   |  9 +++++
 4 files changed, 61 insertions(+)
 create mode 100644 test/Soenneker.Utils.AutoBogus.Tests/Dtos/Simple/TestClassWithAutoPropertyAction.cs
 create mode 100644 test/Soenneker.Utils.AutoBogus.Tests/Dtos/Simple/TestClassWithAutoPropertyFunc.cs

diff --git a/src/Generators/Types/TypeGenerator.cs b/src/Generators/Types/TypeGenerator.cs
index e375476..8a43604 100644
--- a/src/Generators/Types/TypeGenerator.cs
+++ b/src/Generators/Types/TypeGenerator.cs
@@ -4,6 +4,10 @@
 
 namespace Soenneker.Utils.AutoBogus.Generators.Types;
 
+/// <summary>
+/// This is the start of the journey of any top level type, and is used recursively
+/// </summary>
+/// <typeparam name="TType"></typeparam>
 internal sealed class TypeGenerator<TType> : IAutoFakerGenerator
 {
     object? IAutoFakerGenerator.Generate(AutoFakerContext context)
@@ -13,6 +17,10 @@ internal sealed class TypeGenerator<TType> : IAutoFakerGenerator
         // This means the changes are applied to a different instance to the one created here
         CachedType cachedType = context.CacheService.Cache.GetCachedType(typeof(TType));
 
+        // Protects against Generate<Action>, Generate<Func<>>, etc
+        if (cachedType.IsDelegate)
+            return null;
+
         object? instance = context.Binder.CreateInstanceWithRecursionGuard<TType>(context, cachedType);
 
         if (instance == null)
diff --git a/test/Soenneker.Utils.AutoBogus.Tests/AutoFakerTests.cs b/test/Soenneker.Utils.AutoBogus.Tests/AutoFakerTests.cs
index 6367c7a..c96f6f6 100644
--- a/test/Soenneker.Utils.AutoBogus.Tests/AutoFakerTests.cs
+++ b/test/Soenneker.Utils.AutoBogus.Tests/AutoFakerTests.cs
@@ -12,6 +12,7 @@
 using Soenneker.Utils.AutoBogus.Config;
 using Soenneker.Utils.AutoBogus.Tests.Dtos;
 using Soenneker.Utils.AutoBogus.Tests.Dtos.Simple.Delegates;
+using System;
 
 namespace Soenneker.Utils.AutoBogus.Tests;
 
@@ -378,6 +379,40 @@ public void TestClassWithFuncCtor_should_be_null()
         obj.Should().BeNull();
     }
 
+    [Fact]
+    public void Generate_Action_should_be_null()
+    {
+        AutoFaker generator = new();
+        var result = generator.Generate<Action>();
+        result.Should().BeNull();
+    }
+
+    [Fact]
+    public void Generate_Func_should_be_null()
+    {
+        AutoFaker generator = new();
+        var result = generator.Generate<Func<string, string>>();
+        result.Should().BeNull();
+    }
+
+    [Fact]
+    public void Generate_TestClassWithAutoPropertyAction_should_not_be_null_but_property_should_be()
+    {
+        AutoFaker generator = new();
+        var result = generator.Generate<TestClassWithAutoPropertyAction>();
+        result.Should().NotBeNull();
+        result.Action.Should().BeNull();
+    }
+
+    [Fact]
+    public void Generate_TestClassWithAutoPropertyFunc_should_not_be_null_but_property_should_be()
+    {
+        AutoFaker generator = new();
+        var result = generator.Generate<TestClassWithAutoPropertyFunc>();
+        result.Should().NotBeNull();
+        result.Func.Should().BeNull();
+    }
+
     [Fact]
     public void Generate_TestClassWithReadOnlyStringField_should_be_null()
     {
diff --git a/test/Soenneker.Utils.AutoBogus.Tests/Dtos/Simple/TestClassWithAutoPropertyAction.cs b/test/Soenneker.Utils.AutoBogus.Tests/Dtos/Simple/TestClassWithAutoPropertyAction.cs
new file mode 100644
index 0000000..a368977
--- /dev/null
+++ b/test/Soenneker.Utils.AutoBogus.Tests/Dtos/Simple/TestClassWithAutoPropertyAction.cs
@@ -0,0 +1,9 @@
+using System;
+
+namespace Soenneker.Utils.AutoBogus.Tests.Dtos.Simple;
+
+internal class TestClassWithAutoPropertyAction
+{
+    public Action Action { get; set; }
+
+}
\ No newline at end of file
diff --git a/test/Soenneker.Utils.AutoBogus.Tests/Dtos/Simple/TestClassWithAutoPropertyFunc.cs b/test/Soenneker.Utils.AutoBogus.Tests/Dtos/Simple/TestClassWithAutoPropertyFunc.cs
new file mode 100644
index 0000000..72b1ef7
--- /dev/null
+++ b/test/Soenneker.Utils.AutoBogus.Tests/Dtos/Simple/TestClassWithAutoPropertyFunc.cs
@@ -0,0 +1,9 @@
+using System;
+
+namespace Soenneker.Utils.AutoBogus.Tests.Dtos.Simple;
+
+internal class TestClassWithAutoPropertyFunc
+{
+    public Func<string, string> Func { get; set; }
+
+}
\ No newline at end of file