GetCustomAttributes cant return null

src/Adapter/MSTest.TestAdapter/Execution/TypeCache.cs

@@ -898,7 +898,6 @@ private static void SetCustomProperties(TestMethodInfo testMethodInfo, ITestCont
         DebugEx.Assert(testMethodInfo.TestMethod != null, "testMethodInfo.TestMethod is Null");
 
         object[] attributes = testMethodInfo.TestMethod.GetCustomAttributes(typeof(TestPropertyAttribute), false);
-        DebugEx.Assert(attributes != null, "attributes is null");
 
         foreach (TestPropertyAttribute attribute in attributes.Cast<TestPropertyAttribute>())
         {

src/Adapter/MSTest.TestAdapter/Helpers/ReflectHelper.cs

@@ -455,8 +455,8 @@ static Attribute[] GetAttributes(ICustomAttributeProvider attributeProvider, boo
             // Populate the cache
             try
             {
-                object[]? attributes = NotCachedReflectionAccessor.GetCustomAttributesNotCached(attributeProvider, inherit);
-                return attributes is null ? [] : attributes as Attribute[] ?? attributes.Cast<Attribute>().ToArray();
+                object[] attributes = NotCachedReflectionAccessor.GetCustomAttributesNotCached(attributeProvider, inherit);
+                return attributes as Attribute[] ?? attributes.Cast<Attribute>().ToArray();
             }
             catch (Exception ex)
             {
@@ -469,7 +469,7 @@ static Attribute[] GetAttributes(ICustomAttributeProvider attributeProvider, boo
                 }
                 catch (Exception ex2)
                 {
-                    description = string.Format(CultureInfo.CurrentCulture, Resource.ExceptionOccuredWhileGettingTheExceptionDescription, ex.GetType().FullName, ex2.GetType().FullName);                               // ex.GetType().FullName +
+                    description = string.Format(CultureInfo.CurrentCulture, Resource.ExceptionOccuredWhileGettingTheExceptionDescription, ex.GetType().FullName, ex2.GetType().FullName); // ex.GetType().FullName +
                 }
 
                 PlatformServiceProvider.Instance.AdapterTraceLogger.LogWarning(Resource.FailedToGetCustomAttribute, attributeProvider.GetType().FullName!, description);
@@ -490,14 +490,10 @@ internal static class NotCachedReflectionAccessor
         /// <param name="attributeProvider">Member for which attributes needs to be retrieved.</param>
         /// <param name="inherit">If inherited type of attribute.</param>
         /// <returns>All attributes of give type on member.</returns>
-        public static object[]? GetCustomAttributesNotCached(ICustomAttributeProvider attributeProvider, bool inherit)
-        {
-            object[] attributesArray = attributeProvider is MemberInfo memberInfo
+        public static object[] GetCustomAttributesNotCached(ICustomAttributeProvider attributeProvider, bool inherit) =>
+            attributeProvider is MemberInfo memberInfo
                 ? PlatformServiceProvider.Instance.ReflectionOperations.GetCustomAttributes(memberInfo, inherit)
                 : PlatformServiceProvider.Instance.ReflectionOperations.GetCustomAttributes((Assembly)attributeProvider, typeof(Attribute));
-
-            return attributesArray; // TODO: Investigate if we rely on NRE
-        }
     }
 
     internal /* for tests */ void ClearCache()

src/Adapter/MSTest.TestAdapter/SourceGeneration/SourceGeneratedReflectionOperations.cs

@@ -15,8 +15,7 @@ internal sealed class SourceGeneratedReflectionOperations : IReflectionOperation
     public SourceGeneratedReflectionDataProvider ReflectionDataProvider { get; set; }
 #pragma warning restore CS8618 // Non-nullable field must contain a non-null value when exiting constructor. Consider adding the 'required' modifier or declaring as nullable.
 
-    [return: NotNullIfNotNull(nameof(memberInfo))]
-    public object[]? GetCustomAttributes(MemberInfo memberInfo, bool inherit)
+    public object[] GetCustomAttributes(MemberInfo memberInfo, bool inherit)
     {
         if (memberInfo is Type type)
         {
@@ -33,8 +32,7 @@ internal sealed class SourceGeneratedReflectionOperations : IReflectionOperation
         }
     }
 
-    [return: NotNullIfNotNull(nameof(memberInfo))]
-    public object[]? GetCustomAttributes(MemberInfo memberInfo, Type type, bool inherit) => throw new NotImplementedException();
+    public object[] GetCustomAttributes(MemberInfo memberInfo, Type type, bool inherit) => throw new NotImplementedException();
 
     public object[] GetCustomAttributes(Assembly assembly, Type /* the attribute type to find */ type)
     {

src/Adapter/MSTestAdapter.PlatformServices/Interfaces/IReflectionOperations.cs

@@ -1,7 +1,6 @@
 // Copyright (c) Microsoft Corporation. All rights reserved.
 // Licensed under the MIT license. See LICENSE file in the project root for full license information.
 
-using System.Diagnostics.CodeAnalysis;
 using System.Reflection;
 
 namespace Microsoft.VisualStudio.TestPlatform.MSTestAdapter.PlatformServices.Interface;
@@ -17,8 +16,7 @@
     /// <param name="memberInfo"> The member. </param>
     /// <param name="inherit"> True to inspect the ancestors of element; otherwise, false. </param>
     /// <returns> The list of attributes on the member. Empty list if none found. </returns>
-    [return: NotNullIfNotNull(nameof(memberInfo))]
-    object[]? GetCustomAttributes(MemberInfo memberInfo, bool inherit);
+    object[] GetCustomAttributes(MemberInfo memberInfo, bool inherit);
 
     /// <summary>
     /// Gets all the custom attributes of a given type adorned on a member.
@@ -27,8 +25,7 @@
     /// <param name="type"> The attribute type. </param>
     /// <param name="inherit"> True to inspect the ancestors of element; otherwise, false. </param>
     /// <returns> The list of attributes on the member. Empty list if none found. </returns>
-    [return: NotNullIfNotNull(nameof(memberInfo))]
-    object[]? GetCustomAttributes(MemberInfo memberInfo, Type type, bool inherit);
+    object[] GetCustomAttributes(MemberInfo memberInfo, Type type, bool inherit);
 
     /// <summary>
     /// Gets all the custom attributes of a given type on an assembly.

src/Adapter/MSTestAdapter.PlatformServices/PublicAPI/net462/PublicAPI.Unshipped.txt

@@ -1 +1,3 @@
 #nullable enable
+Microsoft.VisualStudio.TestPlatform.MSTestAdapter.PlatformServices.ReflectionOperations.GetCustomAttributes(System.Reflection.MemberInfo! memberInfo, bool inherit) -> object![]!
+Microsoft.VisualStudio.TestPlatform.MSTestAdapter.PlatformServices.ReflectionOperations.GetCustomAttributes(System.Reflection.MemberInfo! memberInfo, System.Type! type, bool inherit) -> object![]!

src/Adapter/MSTestAdapter.PlatformServices/PublicAPI/netstandard2.0/PublicAPI.Unshipped.txt

@@ -1 +1,5 @@
 #nullable enable
+Microsoft.VisualStudio.TestPlatform.MSTestAdapter.PlatformServices.Interface.IReflectionOperations.GetCustomAttributes(System.Reflection.MemberInfo! memberInfo, bool inherit) -> object![]!
+Microsoft.VisualStudio.TestPlatform.MSTestAdapter.PlatformServices.Interface.IReflectionOperations.GetCustomAttributes(System.Reflection.MemberInfo! memberInfo, System.Type! type, bool inherit) -> object![]!
+Microsoft.VisualStudio.TestPlatform.MSTestAdapter.PlatformServices.ReflectionOperations.GetCustomAttributes(System.Reflection.MemberInfo! memberInfo, bool inherit) -> object![]!
+Microsoft.VisualStudio.TestPlatform.MSTestAdapter.PlatformServices.ReflectionOperations.GetCustomAttributes(System.Reflection.MemberInfo! memberInfo, System.Type! type, bool inherit) -> object![]!

src/Adapter/MSTestAdapter.PlatformServices/Services/ReflectionOperations.cs

@@ -1,7 +1,6 @@
 // Copyright (c) Microsoft Corporation. All rights reserved.
 // Licensed under the MIT license. See LICENSE file in the project root for full license information.
 
-using System.Diagnostics.CodeAnalysis;
 using System.Reflection;
 
 using Microsoft.VisualStudio.TestPlatform.MSTestAdapter.PlatformServices.Interface;
@@ -22,8 +21,7 @@
     /// <param name="memberInfo"> The member. </param>
     /// <param name="inherit"> True to inspect the ancestors of element; otherwise, false. </param>
     /// <returns> The list of attributes on the member. Empty list if none found. </returns>
-    [return: NotNullIfNotNull(nameof(memberInfo))]
-    public object[]? GetCustomAttributes(MemberInfo memberInfo, bool inherit) =>
+    public object[] GetCustomAttributes(MemberInfo memberInfo, bool inherit) =>
 #if NETFRAMEWORK
         ReflectionUtility.GetCustomAttributes(memberInfo, inherit).ToArray();
 #else
@@ -37,8 +35,7 @@
     /// <param name="type"> The attribute type. </param>
     /// <param name="inherit"> True to inspect the ancestors of element; otherwise, false. </param>
     /// <returns> The list of attributes on the member. Empty list if none found. </returns>
-    [return: NotNullIfNotNull(nameof(memberInfo))]
-    public object[]? GetCustomAttributes(MemberInfo memberInfo, Type type, bool inherit) =>
+    public object[] GetCustomAttributes(MemberInfo memberInfo, Type type, bool inherit) =>
 #if NETFRAMEWORK
         ReflectionUtility.GetCustomAttributes(memberInfo, type, inherit).ToArray();
 #else

test/IntegrationTests/PlatformServices.Desktop.IntegrationTests/ReflectionUtilityTests.cs

@@ -45,7 +45,6 @@ public void GetCustomAttributesShouldReturnAllAttributes()
 
         IReadOnlyList<object> attributes = ReflectionUtility.GetCustomAttributes(methodInfo, false);
 
-        attributes.Should().NotBeNull();
         attributes.Should().HaveCount(2);
 
         string[] expectedAttributes = ["TestCategory : base", "Owner : base"];
@@ -58,7 +57,6 @@ public void GetCustomAttributesShouldReturnAllAttributesIgnoringBaseInheritance(
 
         IReadOnlyList<object> attributes = ReflectionUtility.GetCustomAttributes(methodInfo, false);
 
-        attributes.Should().NotBeNull();
         attributes.Should().HaveCount(2);
 
         string[] expectedAttributes = ["TestCategory : derived", "Owner : derived"];
@@ -71,7 +69,6 @@ public void GetCustomAttributesShouldReturnAllAttributesWithBaseInheritance()
 
         IReadOnlyList<object> attributes = ReflectionUtility.GetCustomAttributes(methodInfo, true);
 
-        attributes.Should().NotBeNull();
         attributes.Should().HaveCount(3);
 
         // Notice that the Owner on the base method does not show up since it can only be defined once.
@@ -85,7 +82,6 @@ public void GetCustomAttributesOnTypeShouldReturnAllAttributes()
 
         IReadOnlyList<object> attributes = ReflectionUtility.GetCustomAttributes(type, false);
 
-        attributes.Should().NotBeNull();
         attributes.Should().HaveCount(1);
 
         string[] expectedAttributes = ["TestCategory : ba"];
@@ -98,7 +94,6 @@ public void GetCustomAttributesOnTypeShouldReturnAllAttributesIgnoringBaseInheri
 
         IReadOnlyList<object> attributes = ReflectionUtility.GetCustomAttributes(type, false);
 
-        attributes.Should().NotBeNull();
         attributes.Should().HaveCount(1);
 
         string[] expectedAttributes = ["TestCategory : a"];
@@ -111,7 +106,6 @@ public void GetCustomAttributesOnTypeShouldReturnAllAttributesWithBaseInheritanc
 
         IReadOnlyList<object> attributes = ReflectionUtility.GetCustomAttributes(method, true);
 
-        attributes.Should().NotBeNull();
         attributes.Should().HaveCount(2);
 
         string[] expectedAttributes = ["TestCategory : a", "TestCategory : ba"];
@@ -124,7 +118,6 @@ public void GetSpecificCustomAttributesShouldReturnAllAttributes()
 
         IReadOnlyList<object> attributes = ReflectionUtility.GetCustomAttributes(methodInfo, typeof(TestCategoryAttribute), false);
 
-        attributes.Should().NotBeNull();
         attributes.Should().HaveCount(1);
 
         string[] expectedAttributes = ["TestCategory : base"];
@@ -137,7 +130,6 @@ public void GetSpecificCustomAttributesShouldReturnAllAttributesIgnoringBaseInhe
 
         IReadOnlyList<object> attributes = ReflectionUtility.GetCustomAttributes(methodInfo, typeof(TestCategoryAttribute), false);
 
-        attributes.Should().NotBeNull();
         attributes.Should().HaveCount(1);
 
         string[] expectedAttributes = ["TestCategory : derived"];
@@ -151,7 +143,6 @@ public void GetSpecificCustomAttributesShouldReturnAllAttributesWithBaseInherita
 
         IReadOnlyList<object> attributes = ReflectionUtility.GetCustomAttributes(methodInfo, typeof(TestCategoryAttribute), true);
 
-        attributes.Should().NotBeNull();
         attributes.Should().HaveCount(2);
 
         string[] expectedAttributes = ["TestCategory : derived", "TestCategory : base"];
@@ -164,7 +155,6 @@ public void GetCustomAttributesShouldReturnAllAttributesIncludingUserDefinedAttr
 
         IReadOnlyList<object> attributes = ReflectionUtility.GetCustomAttributes(methodInfo, null, true);
 
-        attributes.Should().NotBeNull();
         attributes.Should().HaveCount(3);
 
         string[] expectedAttributes = ["Duration : superfast", "TestCategory : base", "Owner : base"];
@@ -177,7 +167,6 @@ public void GetSpecificCustomAttributesShouldReturnAllAttributesIncludingUserDef
 
         IReadOnlyList<object> attributes = ReflectionUtility.GetCustomAttributes(methodInfo, typeof(TestPropertyAttribute), true);
 
-        attributes.Should().NotBeNull();
         attributes.Should().HaveCount(1);
 
         string[] expectedAttributes = ["Duration : superfast"];
@@ -190,7 +179,6 @@ public void GetSpecificCustomAttributesShouldReturnArrayAttributesAsWell()
 
         IReadOnlyList<object> attributes = ReflectionUtility.GetCustomAttributes(methodInfo, typeof(CategoryArrayAttribute), true);
 
-        attributes.Should().NotBeNull();
         attributes.Should().HaveCount(1);
 
         string[] expectedAttributes = ["CategoryAttribute : foo,foo2"];
@@ -203,7 +191,6 @@ public void GetSpecificCustomAttributesOnTypeShouldReturnAllAttributes()
 
         IReadOnlyList<object> attributes = ReflectionUtility.GetCustomAttributes(type, typeof(TestCategoryAttribute), false);
 
-        attributes.Should().NotBeNull();
         attributes.Should().HaveCount(1);
 
         string[] expectedAttributes = ["TestCategory : ba"];
@@ -216,7 +203,6 @@ public void GetSpecificCustomAttributesOnTypeShouldReturnAllAttributesIgnoringBa
 
         IReadOnlyList<object> attributes = ReflectionUtility.GetCustomAttributes(type, typeof(TestCategoryAttribute), false);
 
-        attributes.Should().NotBeNull();
         attributes.Should().HaveCount(1);
 
         string[] expectedAttributes = ["TestCategory : a"];
@@ -229,7 +215,6 @@ public void GetSpecificCustomAttributesOnTypeShouldReturnAllAttributesWithBaseIn
 
         IReadOnlyList<object> attributes = ReflectionUtility.GetCustomAttributes(method, typeof(TestCategoryAttribute), true);
 
-        attributes.Should().NotBeNull();
         attributes.Should().HaveCount(2);
 
         string[] expectedAttributes = ["TestCategory : a", "TestCategory : ba"];
@@ -242,7 +227,6 @@ public void GetSpecificCustomAttributesOnAssemblyShouldReturnAllAttributes()
 
         List<Attribute> attributes = ReflectionUtility.GetCustomAttributes(asm, typeof(TestCategoryAttribute));
 
-        attributes.Should().NotBeNull();
         attributes.Should().HaveCount(2);
 
         string[] expectedAttributes = ["TestCategory : a1", "TestCategory : a2"];

test/UnitTests/MSTestAdapter.PlatformServices.UnitTests/Services/DesktopReflectionOperationsTests.cs

@@ -25,7 +25,6 @@ public void GetCustomAttributesShouldReturnAllAttributes()
 
         object[] attributes = _reflectionOperations.GetCustomAttributes(methodInfo, false);
 
-        Verify(attributes is not null);
         Verify(attributes.Length == 2);
 
         string[] expectedAttributes = ["DummyA : base", "DummySingleA : base"];
@@ -38,7 +37,6 @@ public void GetCustomAttributesOnTypeShouldReturnAllAttributes()
 
         object[] attributes = _reflectionOperations.GetCustomAttributes(type, false);
 
-        Verify(attributes is not null);
         Verify(attributes.Length == 1);
 
         string[] expectedAttributes = ["DummyA : ba"];
@@ -51,7 +49,6 @@ public void GetSpecificCustomAttributesOnAssemblyShouldReturnAllAttributes()
 
         object[] attributes = _reflectionOperations.GetCustomAttributes(asm, typeof(ReflectionUtilityTests.DummyAAttribute));
 
-        Verify(attributes is not null);
         Verify(attributes.Length == 2);
 
         string[] expectedAttributes = ["DummyA : a1", "DummyA : a2"];

test/UnitTests/MSTestAdapter.PlatformServices.UnitTests/Services/ReflectionOperationsTests.cs

@@ -21,7 +21,6 @@ public void GetCustomAttributesShouldReturnAllAttributes()
 
         object[] attributes = _reflectionOperations.GetCustomAttributes(methodInfo, false);
 
-        Verify(attributes is not null);
         Verify(attributes.Length == 2);
 
         string[] expectedAttributes = ["DummyA : base", "DummySingleA : base"];
@@ -34,7 +33,6 @@ public void GetCustomAttributesShouldReturnAllAttributesIgnoringBaseInheritance(
 
         object[] attributes = _reflectionOperations.GetCustomAttributes(methodInfo, false);
 
-        Verify(attributes is not null);
         Verify(attributes.Length == 2);
 
         string[] expectedAttributes = ["DummyA : derived", "DummySingleA : derived"];
@@ -47,7 +45,6 @@ public void GetCustomAttributesShouldReturnAllAttributesWithBaseInheritance()
 
         object[] attributes = _reflectionOperations.GetCustomAttributes(methodInfo, true);
 
-        Verify(attributes is not null);
         Verify(attributes.Length == 3);
 
         // Notice that the DummySingleA on the base method does not show up since it can only be defined once.
@@ -61,7 +58,6 @@ public void GetCustomAttributesOnTypeShouldReturnAllAttributes()
 
         object[] attributes = _reflectionOperations.GetCustomAttributes(type, false);
 
-        Verify(attributes is not null);
         Verify(attributes.Length == 1);
 
         string[] expectedAttributes = ["DummyA : ba"];
@@ -74,7 +70,6 @@ public void GetCustomAttributesOnTypeShouldReturnAllAttributesIgnoringBaseInheri
 
         object[] attributes = _reflectionOperations.GetCustomAttributes(type, false);
 
-        Verify(attributes is not null);
         Verify(attributes.Length == 1);
 
         string[] expectedAttributes = ["DummyA : a"];
@@ -87,7 +82,6 @@ public void GetCustomAttributesOnTypeShouldReturnAllAttributesWithBaseInheritanc
 
         object[] attributes = _reflectionOperations.GetCustomAttributes(method, true);
 
-        Verify(attributes is not null);
         Verify(attributes.Length == 2);
 
         string[] expectedAttributes = ["DummyA : a", "DummyA : ba"];
@@ -100,7 +94,6 @@ public void GetSpecificCustomAttributesShouldReturnAllAttributes()
 
         object[] attributes = _reflectionOperations.GetCustomAttributes(methodInfo, typeof(DummyAAttribute), false);
 
-        Verify(attributes is not null);
         Verify(attributes.Length == 1);
 
         string[] expectedAttributes = ["DummyA : base"];
@@ -113,7 +106,6 @@ public void GetSpecificCustomAttributesShouldReturnAllAttributesIgnoringBaseInhe
 
         object[] attributes = _reflectionOperations.GetCustomAttributes(methodInfo, typeof(DummyAAttribute), false);
 
-        Verify(attributes is not null);
         Verify(attributes.Length == 1);
 
         string[] expectedAttributes = ["DummyA : derived"];
@@ -126,7 +118,6 @@ public void GetSpecificCustomAttributesShouldReturnAllAttributesWithBaseInherita
 
         object[] attributes = _reflectionOperations.GetCustomAttributes(methodInfo, typeof(DummyAAttribute), true);
 
-        Verify(attributes is not null);
         Verify(attributes.Length == 2);
 
         string[] expectedAttributes = ["DummyA : derived", "DummyA : base"];
@@ -139,7 +130,6 @@ public void GetSpecificCustomAttributesOnTypeShouldReturnAllAttributes()
 
         object[] attributes = _reflectionOperations.GetCustomAttributes(type, typeof(DummyAAttribute), false);
 
-        Verify(attributes is not null);
         Verify(attributes.Length == 1);
 
         string[] expectedAttributes = ["DummyA : ba"];
@@ -152,7 +142,6 @@ public void GetSpecificCustomAttributesOnTypeShouldReturnAllAttributesIgnoringBa
 
         object[] attributes = _reflectionOperations.GetCustomAttributes(type, typeof(DummyAAttribute), false);
 
-        Verify(attributes is not null);
         Verify(attributes.Length == 1);
 
         string[] expectedAttributes = ["DummyA : a"];
@@ -165,7 +154,6 @@ public void GetSpecificCustomAttributesOnTypeShouldReturnAllAttributesWithBaseIn
 
         object[] attributes = _reflectionOperations.GetCustomAttributes(method, typeof(DummyAAttribute), true);
 
-        Verify(attributes is not null);
         Verify(attributes.Length == 2);
 
         string[] expectedAttributes = ["DummyA : a", "DummyA : ba"];
@@ -178,7 +166,6 @@ public void GetSpecificCustomAttributesOnAssemblyShouldReturnAllAttributes()
 
         object[] attributes = _reflectionOperations.GetCustomAttributes(asm, typeof(DummyAAttribute));
 
-        Verify(attributes is not null);
         Verify(attributes.Length == 2);
 
         string[] expectedAttributes = ["DummyA : a1", "DummyA : a2"];