From 8d61e4324cc5c39f5768ca8265e4fe5d13c53c2e Mon Sep 17 00:00:00 2001
From: wuyangfan <yangfan.wu@succaiss.com>
Date: Mon, 25 May 2026 14:01:50 +0800
Subject: [PATCH 1/2] test: ensure Compile skips open generic mapping rules
 (#925)

Add regression coverage for configuring ClassA<> to ClassB<> and calling
Compile() without throwing, matching the documented validation behavior.

Co-authored-by: Cursor <cursoragent@cursor.com>
---
 .../WhenMappingWithOpenGenerics.cs            | 27 +++++++++++++++++++
 1 file changed, 27 insertions(+)

diff --git a/src/Mapster.Tests/WhenMappingWithOpenGenerics.cs b/src/Mapster.Tests/WhenMappingWithOpenGenerics.cs
index 7abb5e1f..118f1c75 100644
--- a/src/Mapster.Tests/WhenMappingWithOpenGenerics.cs
+++ b/src/Mapster.Tests/WhenMappingWithOpenGenerics.cs
@@ -33,6 +33,23 @@ public void Setting_From_OpenGeneric_Has_No_SideEffect()
             var cCopy = c.Adapt<C>(config);
         }
 
+        /// <summary>
+        /// https://github.com/MapsterMapper/Mapster/issues/925
+        /// </summary>
+        [TestMethod]
+        public void Compile_With_Open_Generic_Mapping_Does_Not_Throw()
+        {
+            var config = new TypeAdapterConfig();
+            config.ForType(typeof(ClassA<>), typeof(ClassB<>));
+
+            Should.NotThrow(() => config.Compile());
+
+            var classA = new ClassA<int> { Variable = 15 };
+            var classB = classA.Adapt<ClassB<int>>(config);
+
+            classB.Variable.ShouldBe(15);
+        }
+
         [TestMethod]
         public void MapOpenGenericsUseInherits()
         {
@@ -102,5 +119,15 @@ class A<T> { public string AProperty { get; set; } }
         class B<T> { public string BProperty { get; set; } }
 
         class C { public string BProperty { get; set; } }
+
+        class ClassA<T>
+        {
+            public T? Variable { get; set; }
+        }
+
+        class ClassB<T>
+        {
+            public T? Variable { get; set; }
+        }
     }
 }

From 2c37aa1cfd9e8c3a4ea20e491d91f85f86d72ece Mon Sep 17 00:00:00 2001
From: DocSvartz <svartzdoctor@gmail.com>
Date: Mon, 15 Jun 2026 13:24:35 +0500
Subject: [PATCH 2/2] fix(test): Drop OpenGeneric compile check because a
 separate test was added

---
 src/Mapster.Tests/WhenMappingWithOpenGenerics.cs | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/src/Mapster.Tests/WhenMappingWithOpenGenerics.cs b/src/Mapster.Tests/WhenMappingWithOpenGenerics.cs
index 118f1c75..19891357 100644
--- a/src/Mapster.Tests/WhenMappingWithOpenGenerics.cs
+++ b/src/Mapster.Tests/WhenMappingWithOpenGenerics.cs
@@ -24,9 +24,7 @@ public void Setting_From_OpenGeneric_Has_No_SideEffect()
             config
                 .NewConfig(typeof(A<>), typeof(B<>))
                 .Map("BProperty", "AProperty");
-
-            config.Compile(); // is not throw exception
-
+                
             var a = new A<C> { AProperty = "A" };
             var c = new C { BProperty = "C" };
             var b = a.Adapt<B<C>>(config); // successful mapping