Fix static member exports to not instantiate declaring type

src/Microsoft.VisualStudio.Composition/ExportProvider.cs

@@ -568,8 +568,17 @@ private protected ExportInfo CreateExport(ImportDefinition importDefinition, IRe
                 memberValueFactory = () =>
                 {
                     Verify.NotDisposed(this);
-                    PartLifecycleTracker maybeSharedValueFactory = this.GetOrCreateValue(originalPartTypeRef, constructedPartTypeRef, partSharingBoundary, importDefinition.Metadata, nonSharedInstanceRequired, nonSharedPartOwner: null);
-                    return (GetValueFromMember(maybeSharedValueFactory.GetValueReadyToRetrieveExportingMembers(), exportingMemberRef.MemberInfo), nonSharedInstanceRequired ? maybeSharedValueFactory : null);
+
+                    // For static members, we don't need to instantiate the declaring type
+                    if (exportingMemberRef.IsStatic())
+                    {
+                        return (GetValueFromMember(null, exportingMemberRef.MemberInfo), null);
+                    }
+                    else
+                    {
+                        PartLifecycleTracker maybeSharedValueFactory = this.GetOrCreateValue(originalPartTypeRef, constructedPartTypeRef, partSharingBoundary, importDefinition.Metadata, nonSharedInstanceRequired, nonSharedPartOwner: null);
+                        return (GetValueFromMember(maybeSharedValueFactory.GetValueReadyToRetrieveExportingMembers(), exportingMemberRef.MemberInfo), nonSharedInstanceRequired ? maybeSharedValueFactory : null);
+                    }
                 };
             }
 

src/Microsoft.VisualStudio.Composition/RuntimeExportProviderFactory+RuntimeExportProvider.cs

@@ -290,13 +290,31 @@ private object CreateExportFactory(RuntimePartLifecycleTracker importingPartTrac
                     return exportProvider;
                 }
 
+                // For static member exports, we don't need to create a part lifecycle tracker
+                if (export.MemberRef != null && export.Member!.IsStatic())
+                {
+                    partLifecycle = null;
+                    return lazy ? ConstructLazyStaticExportedValue(export) : 
+                                  ConstructStaticExportedValue(export);
+                }
+
                 var constructedType = GetPartConstructedTypeRef(exportingRuntimePart, import.Metadata);
 
                 partLifecycle = this.GetOrCreateValue(import, exportingRuntimePart, exportingRuntimePart.TypeRef, constructedType, importingPartTracker);
 
                 return lazy ? ConstructLazyExportedValue(import, export, importingPartTracker, partLifecycle, this.faultCallback) :
                               ConstructExportedValue(import, export, importingPartTracker, partLifecycle, this.faultCallback);
 
+                static Func<object?> ConstructLazyStaticExportedValue(RuntimeComposition.RuntimeExport export)
+                {
+                    return () => ConstructStaticExportedValue(export);
+                }
+
+                static object? ConstructStaticExportedValue(RuntimeComposition.RuntimeExport export)
+                {
+                    return GetValueFromMember(null, export.Member!, null, export.ExportedValueTypeRef.Resolve());
+                }
+
                 static Func<object?> ConstructLazyExportedValue(RuntimeComposition.RuntimeImport import, RuntimeComposition.RuntimeExport export, RuntimePartLifecycleTracker? importingPartTracker, PartLifecycleTracker partLifecycle, ReportFaultCallback? faultCallback)
                 {
                     // Avoid inlining this method into its parent to avoid non-lazy path from paying for capture allocation

test/Microsoft.VisualStudio.Composition.Tests/StaticMemberExportsTests.cs

@@ -11,6 +11,7 @@ namespace Microsoft.VisualStudio.Composition.Tests
     using Xunit;
     using CompositionFailedException = Microsoft.VisualStudio.Composition.CompositionFailedException;
     using MefV1 = System.ComponentModel.Composition;
+    using MefV2 = System.Composition;
 
     [Trait("Static", "")]
     public class StaticMemberExportsTests
@@ -194,5 +195,104 @@ public class ImportManyWithMetadataPart
             [MefV1.ImportMany("Property")]
             public List<Lazy<string, IDictionary<string, object>>> ImportingMember { get; set; } = null!;
         }
+
+        // Test class to verify static members don't cause instantiation
+        public class ClassWithStaticMemberExports
+        {
+            private static bool constructorCalled = false;
+
+            public static bool ConstructorCalled
+            {
+                get { return constructorCalled; }
+                set { constructorCalled = value; }
+            }
+
+            public ClassWithStaticMemberExports()
+            {
+                constructorCalled = true;
+            }
+
+            [MefV1.Export("StaticField")]
+            [MefV2.Export("StaticField")]
+            public static string StaticField = "StaticFieldValue";
+
+            [MefV1.Export("StaticProperty")]
+            [MefV2.Export("StaticProperty")]
+            public static string StaticProperty => "StaticPropertyValue";
+
+            [MefV1.Export("StaticMethod")]
+            [MefV2.Export("StaticMethod")]
+            public static string StaticMethod() => "StaticMethodValue";
+        }
+
+        // Test class with mixed static and instance exports
+        public class ClassWithMixedExports
+        {
+            private static bool constructorCalled = false;
+
+            public static bool ConstructorCalled
+            {
+                get { return constructorCalled; }
+                set { constructorCalled = value; }
+            }
+
+            public ClassWithMixedExports()
+            {
+                constructorCalled = true;
+            }
+
+            [MefV1.Export("StaticMixed")]
+            [MefV2.Export("StaticMixed")]
+            public static string StaticExport = "StaticValue";
+
+            [MefV1.Export("InstanceMixed")]
+            [MefV2.Export("InstanceMixed")]
+            public string InstanceExport => "InstanceValue";
+        }
+
+        [MefFact(CompositionEngines.V1Compat | CompositionEngines.V2Compat | CompositionEngines.V3EmulatingV1 | CompositionEngines.V3EmulatingV2, typeof(ClassWithStaticMemberExports))]
+        public void StaticFieldExportDoesNotInstantiateClass(IContainer container)
+        {
+            ClassWithStaticMemberExports.ConstructorCalled = false;
+            var value = container.GetExportedValue<string>("StaticField");
+            Assert.Equal("StaticFieldValue", value);
+            Assert.False(ClassWithStaticMemberExports.ConstructorCalled, "Constructor should not be called for static field export");
+        }
+
+        [MefFact(CompositionEngines.V1Compat | CompositionEngines.V2Compat | CompositionEngines.V3EmulatingV1 | CompositionEngines.V3EmulatingV2, typeof(ClassWithStaticMemberExports))]
+        public void StaticPropertyExportDoesNotInstantiateClass(IContainer container)
+        {
+            ClassWithStaticMemberExports.ConstructorCalled = false;
+            var value = container.GetExportedValue<string>("StaticProperty");
+            Assert.Equal("StaticPropertyValue", value);
+            Assert.False(ClassWithStaticMemberExports.ConstructorCalled, "Constructor should not be called for static property export");
+        }
+
+        [MefFact(CompositionEngines.V1Compat | CompositionEngines.V2Compat | CompositionEngines.V3EmulatingV1 | CompositionEngines.V3EmulatingV2, typeof(ClassWithStaticMemberExports))]
+        public void StaticMethodExportDoesNotInstantiateClass(IContainer container)
+        {
+            ClassWithStaticMemberExports.ConstructorCalled = false;
+            var value = container.GetExportedValue<Func<string>>("StaticMethod");
+            Assert.Equal("StaticMethodValue", value());
+            Assert.False(ClassWithStaticMemberExports.ConstructorCalled, "Constructor should not be called for static method export");
+        }
+
+        [MefFact(CompositionEngines.V1Compat | CompositionEngines.V2Compat | CompositionEngines.V3EmulatingV1 | CompositionEngines.V3EmulatingV2, typeof(ClassWithMixedExports))]
+        public void StaticExportInMixedClassDoesNotInstantiateClass(IContainer container)
+        {
+            ClassWithMixedExports.ConstructorCalled = false;
+            var value = container.GetExportedValue<string>("StaticMixed");
+            Assert.Equal("StaticValue", value);
+            Assert.False(ClassWithMixedExports.ConstructorCalled, "Constructor should not be called when accessing only static export");
+        }
+
+        [MefFact(CompositionEngines.V1Compat | CompositionEngines.V2Compat | CompositionEngines.V3EmulatingV1 | CompositionEngines.V3EmulatingV2, typeof(ClassWithMixedExports))]
+        public void InstanceExportInMixedClassDoesInstantiateClass(IContainer container)
+        {
+            ClassWithMixedExports.ConstructorCalled = false;
+            var value = container.GetExportedValue<string>("InstanceMixed");
+            Assert.Equal("InstanceValue", value);
+            Assert.True(ClassWithMixedExports.ConstructorCalled, "Constructor should be called when accessing instance export");
+        }
     }
 }