From 98b467184b959bf5a0bda4dd828219945579c73f Mon Sep 17 00:00:00 2001
From: Eric Erhardt <eric.erhardt@microsoft.com>
Date: Tue, 1 Dec 2020 15:47:53 -0600
Subject: [PATCH] Remove unnecessary IsStatic checks in ActivatorUtilities

---
 .../src/ActivatorUtilities.cs                 | 45 +++++++------------
 .../ActivatorUtilitiesTests.cs                |  9 +++-
 2 files changed, 24 insertions(+), 30 deletions(-)

diff --git a/src/libraries/Microsoft.Extensions.DependencyInjection.Abstractions/src/ActivatorUtilities.cs b/src/libraries/Microsoft.Extensions.DependencyInjection.Abstractions/src/ActivatorUtilities.cs
index 25a7267924bc64..92be14984876c8 100644
--- a/src/libraries/Microsoft.Extensions.DependencyInjection.Abstractions/src/ActivatorUtilities.cs
+++ b/src/libraries/Microsoft.Extensions.DependencyInjection.Abstractions/src/ActivatorUtilities.cs
@@ -40,33 +40,30 @@ public static object CreateInstance(
             {
                 foreach (ConstructorInfo? constructor in instanceType.GetConstructors())
                 {
-                    if (!constructor.IsStatic)
-                    {
-                        var matcher = new ConstructorMatcher(constructor);
-                        bool isPreferred = constructor.IsDefined(typeof(ActivatorUtilitiesConstructorAttribute), false);
-                        int length = matcher.Match(parameters);
+                    var matcher = new ConstructorMatcher(constructor);
+                    bool isPreferred = constructor.IsDefined(typeof(ActivatorUtilitiesConstructorAttribute), false);
+                    int length = matcher.Match(parameters);
 
-                        if (isPreferred)
+                    if (isPreferred)
+                    {
+                        if (seenPreferred)
                         {
-                            if (seenPreferred)
-                            {
-                                ThrowMultipleCtorsMarkedWithAttributeException();
-                            }
-
-                            if (length == -1)
-                            {
-                                ThrowMarkedCtorDoesNotTakeAllProvidedArguments();
-                            }
+                            ThrowMultipleCtorsMarkedWithAttributeException();
                         }
 
-                        if (isPreferred || bestLength < length)
+                        if (length == -1)
                         {
-                            bestLength = length;
-                            bestMatcher = matcher;
+                            ThrowMarkedCtorDoesNotTakeAllProvidedArguments();
                         }
+                    }
 
-                        seenPreferred |= isPreferred;
+                    if (isPreferred || bestLength < length)
+                    {
+                        bestLength = length;
+                        bestMatcher = matcher;
                     }
+
+                    seenPreferred |= isPreferred;
                 }
             }
 
@@ -232,11 +229,6 @@ private static bool TryFindMatchingConstructor(
         {
             foreach (ConstructorInfo? constructor in instanceType.GetConstructors())
             {
-                if (constructor.IsStatic)
-                {
-                    continue;
-                }
-
                 if (TryCreateParameterMap(constructor.GetParameters(), argumentTypes, out int?[] tempParameterMap))
                 {
                     if (matchingConstructor != null)
@@ -268,11 +260,6 @@ private static bool TryFindPreferredConstructor(
             bool seenPreferred = false;
             foreach (ConstructorInfo? constructor in instanceType.GetConstructors())
             {
-                if (constructor.IsStatic)
-                {
-                    continue;
-                }
-
                 if (constructor.IsDefined(typeof(ActivatorUtilitiesConstructorAttribute), false))
                 {
                     if (seenPreferred)
diff --git a/src/libraries/Microsoft.Extensions.DependencyInjection/tests/DI.Specification.Tests/ActivatorUtilitiesTests.cs b/src/libraries/Microsoft.Extensions.DependencyInjection/tests/DI.Specification.Tests/ActivatorUtilitiesTests.cs
index 8ef93a5179ba56..8bfd657ae0de0b 100644
--- a/src/libraries/Microsoft.Extensions.DependencyInjection/tests/DI.Specification.Tests/ActivatorUtilitiesTests.cs
+++ b/src/libraries/Microsoft.Extensions.DependencyInjection/tests/DI.Specification.Tests/ActivatorUtilitiesTests.cs
@@ -141,7 +141,7 @@ public void TypeActivatorCanDisambiguateConstructorsWithUniqueArguments(CreateIn
 
         public static IEnumerable<object[]> TypesWithNonPublicConstructorData =>
             CreateInstanceFuncs.Zip(
-                    new[] { typeof(ClassWithPrivateCtor), typeof(ClassWithInternalConstructor), typeof(ClassWithProtectedConstructor) },
+                    new[] { typeof(ClassWithPrivateCtor), typeof(ClassWithInternalConstructor), typeof(ClassWithProtectedConstructor), typeof(StaticConstructorClass) },
                     (a, b) => new object[] { a[0], b });
 
         [Theory]
@@ -401,5 +401,12 @@ public Bar()
                 throw new InvalidOperationException("some error");
             }
         }
+
+        class StaticConstructorClass
+        {
+            static StaticConstructorClass() { }
+
+            private StaticConstructorClass() { }
+        }
     }
 }