fix: prevent null initializing readonly members (#678)

riok · Aug 28, 2023 · f3d78b4 · f3d78b4
1 parent 71cbfdd
commit f3d78b4
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Showing 2 changed files with 26 additions and 0 deletions.
diff --git a/...Mapperly/Descriptors/MappingBodyBuilders/BuilderContext/MembersContainerBuilderContext.cs b/...Mapperly/Descriptors/MappingBodyBuilders/BuilderContext/MembersContainerBuilderContext.cs
@@ -38,6 +38,10 @@ private void AddNullMemberInitializers(IMemberAssignmentMappingContainer contain
         {
             var nullablePath = new MemberPath(nullableTrailPath);
             var type = nullablePath.Member.Type;
+
+            if (!nullablePath.Member.CanSet)
+                continue;
+
             if (!BuilderContext.SymbolAccessor.HasAccessibleParameterlessConstructor(type))
             {
                 BuilderContext.ReportDiagnostic(DiagnosticDescriptors.NoParameterlessConstructorFound, type);

diff --git a/test/Riok.Mapperly.Tests/Mapping/ObjectPropertyFlatteningTest.cs b/test/Riok.Mapperly.Tests/Mapping/ObjectPropertyFlatteningTest.cs
@@ -390,6 +390,28 @@ public void ManualUnflattenedPropertyNullablePath()
             );
     }
 
+    [Fact]
+    public void ManualUnflattenedPropertyReadOnlyNullablePath()
+    {
+        var source = TestSourceBuilder.MapperWithBodyAndTypes(
+            "[MapProperty($\"MyValueId\", \"Value.Id\")] partial B Map(A source);",
+            "class A { public string MyValueId { get; set; } }",
+            "class B { public C? Value { get; } }",
+            "class C { public string Id { get; set; } public string Id2 { get; set; } }"
+        );
+
+        TestHelper
+            .GenerateMapper(source)
+            .Should()
+            .HaveSingleMethodBody(
+                """
+                var target = new global::B();
+                target.Value.Id = source.MyValueId;
+                return target;
+                """
+            );
+    }
+
     [Fact]
     public void ManualUnflattenedPropertyDeepNullablePath()
     {