From 377261312f4a7a94770dabefaab84aff19e3488e Mon Sep 17 00:00:00 2001
From: wuyangfan <yangfan.wu@succaiss.com>
Date: Mon, 25 May 2026 15:15:08 +0800
Subject: [PATCH] test: cover MapToTarget for types with read-only base
 properties (#918)

Regression test for same-type Adapt(target) when the destination type
inherits read-only members alongside writable properties.

Co-authored-by: Cursor <cursoragent@cursor.com>
---
 ...gMapToTargetMixedReadOnlyBaseRegression.cs | 38 +++++++++++++++++++
 1 file changed, 38 insertions(+)
 create mode 100644 src/Mapster.Tests/WhenMappingMapToTargetMixedReadOnlyBaseRegression.cs

diff --git a/src/Mapster.Tests/WhenMappingMapToTargetMixedReadOnlyBaseRegression.cs b/src/Mapster.Tests/WhenMappingMapToTargetMixedReadOnlyBaseRegression.cs
new file mode 100644
index 00000000..d83f7f06
--- /dev/null
+++ b/src/Mapster.Tests/WhenMappingMapToTargetMixedReadOnlyBaseRegression.cs
@@ -0,0 +1,38 @@
+using Microsoft.VisualStudio.TestTools.UnitTesting;
+using Shouldly;
+
+namespace Mapster.Tests
+{
+    /// <summary>
+    /// https://github.com/MapsterMapper/Mapster/issues/918
+    /// </summary>
+    [TestClass]
+    public class WhenMappingMapToTargetMixedReadOnlyBaseRegression
+    {
+        [TestMethod]
+        public void MapToTarget_SameType_WithMixedReadOnlyBaseProperties_UpdatesDestination()
+        {
+            var source = new Station918 { RowNo = 100, Location = "Source" };
+            var destination = new Station918 { RowNo = 0, Location = "Destination" };
+
+            source.Adapt(destination);
+
+            destination.RowNo.ShouldBe(100);
+            destination.Location.ShouldBe("Source");
+        }
+
+        public abstract class ValidationBase918
+        {
+            public bool HasErrors { get; }
+
+            public string? ErrorMessage { get; }
+        }
+
+        public class Station918 : ValidationBase918
+        {
+            public int RowNo { get; set; }
+
+            public string Location { get; set; } = string.Empty;
+        }
+    }
+}