Handle explicit interface implementations of GetHashCode

dotnet · Jan 12, 2024 · 01acfa3 · 01acfa3
1 parent 43456c1
commit 01acfa3
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Showing 2 changed files with 99 additions and 2 deletions.
diff --git a/...ft.CodeQuality.Analyzers/ApiDesignGuidelines/DoNotRaiseExceptionsInUnexpectedLocations.cs b/...ft.CodeQuality.Analyzers/ApiDesignGuidelines/DoNotRaiseExceptionsInUnexpectedLocations.cs
@@ -186,7 +186,7 @@ private static List<MethodCategory> GetMethodCategories(Compilation compilation)
                     compilation.GetOrCreateTypeByMetadataName(WellKnownTypeNames.SystemNotSupportedException),
                     compilation.GetOrCreateTypeByMetadataName(WellKnownTypeNames.SystemArgumentException)),
 
-                new MethodCategory(IsGetHashCodeInterfaceImplementation, true,
+                new MethodCategory(IsGetHashCodeInterfaceImplementation, false,
                     HasAllowedExceptionsRule,
                     compilation.GetOrCreateTypeByMetadataName(WellKnownTypeNames.SystemArgumentException)),
 
@@ -281,7 +281,8 @@ private static bool IsEqualsInterfaceImplementation(IMethodSymbol method, Compil
         /// <returns></returns>
         private static bool IsGetHashCodeInterfaceImplementation(IMethodSymbol method, Compilation compilation)
         {
-            if (method.Name != WellKnownMemberNames.ObjectGetHashCode)
+            if (method.Name != WellKnownMemberNames.ObjectGetHashCode &&
+                method.ExplicitInterfaceImplementations.Length == 0)
             {
                 return false;
             }

diff --git a/...deQuality.Analyzers/ApiDesignGuidelines/DoNotRaiseExceptionsInUnexpectedLocationsTests.cs b/...deQuality.Analyzers/ApiDesignGuidelines/DoNotRaiseExceptionsInUnexpectedLocationsTests.cs
@@ -395,6 +395,32 @@ public int GetHashCode(object obj)
                          GetCSharpAllowedExceptionsResultAt(8, 9, "GetHashCode", "Exception"));
         }
 
+        [Fact]
+        public async Task CSharpIHashCodeProviderGetHashCodeAsExplicitInterfaceImplementationAsync()
+        {
+            var code = @"
+using System;
+using System.Collections;
+public class C : IHashCodeProvider
+{
+    int IHashCodeProvider.GetHashCode(object obj)
+    {
+        throw new Exception();
+    }
+}
+
+public class D : IHashCodeProvider
+{
+    int IHashCodeProvider.GetHashCode(object obj)
+    {
+        throw new ArgumentException(""obj""); // this is fine.
+    }
+}
+";
+            await VerifyCS.VerifyAnalyzerAsync(code,
+                GetCSharpAllowedExceptionsResultAt(8, 9, "System.Collections.IHashCodeProvider.GetHashCode", "Exception"));
+        }
+
         [Fact]
         public async Task BasicIHashCodeProviderGetHashCodeAsync()
         {
@@ -420,6 +446,31 @@ End Class
                         GetBasicAllowedExceptionsResultAt(7, 9, "GetHashCode", "Exception"));
         }
 
+        [Fact]
+        public async Task BasicIHashCodeProviderGetHashCodeAsExplicitInterfaceImplementationAsync()
+        {
+            var code = @"
+Imports System
+Imports System.Collections
+Public Class C
+    Implements IHashCodeProvider
+    Private Function GetHashCode(obj As Object) As Integer Implements IHashCodeProvider.GetHashCode
+        Throw New Exception()
+    End Function
+End Class
+
+Public Class D
+    Implements IHashCodeProvider
+    Private Function GetHashCode(obj As Object) As Integer Implements IHashCodeProvider.GetHashCode
+        Throw New ArgumentException() ' This is fine.
+    End Function
+End Class
+";
+
+            await VerifyVB.VerifyAnalyzerAsync(code,
+                GetBasicAllowedExceptionsResultAt(7, 9, "GetHashCode", "Exception"));
+        }
+
         [Fact]
         public async Task CSharpIEqualityComparerAsync()
         {
@@ -443,6 +494,29 @@ public int GetHashCode(C obj)
                          GetCSharpAllowedExceptionsResultAt(12, 9, "GetHashCode", "Exception"));
         }
 
+        [Fact]
+        public async Task CSharpIEqualityComparerWithExplicitInterfaceImplementationsAsync()
+        {
+            var code = @"
+using System;
+using System.Collections.Generic;
+public class C : IEqualityComparer<C>
+{
+    bool IEqualityComparer<C>.Equals(C obj1, C obj2)
+    {
+        throw new Exception();
+    }
+    int IEqualityComparer<C>.GetHashCode(C obj)
+    {
+        throw new Exception();
+    }
+}
+";
+            await VerifyCS.VerifyAnalyzerAsync(code,
+                GetCSharpNoExceptionsResultAt(8, 9, "System.Collections.Generic.IEqualityComparer<C>.Equals", "Exception"),
+                GetCSharpAllowedExceptionsResultAt(12, 9, "System.Collections.Generic.IEqualityComparer<C>.GetHashCode", "Exception"));
+        }
+
         [Fact]
         public async Task BasicIEqualityComparerAsync()
         {
@@ -458,6 +532,28 @@ End Function
         Throw New Exception()
     End Function
 End Class
+";
+
+            await VerifyVB.VerifyAnalyzerAsync(code,
+                GetBasicNoExceptionsResultAt(7, 9, "Equals", "Exception"),
+                GetBasicAllowedExceptionsResultAt(10, 9, "GetHashCode", "Exception"));
+        }
+
+        [Fact]
+        public async Task BasicIEqualityComparerWithExplicitInterfaceImplementationsAsync()
+        {
+            var code = @"
+Imports System
+Imports System.Collections.Generic
+Public Class C
+    Implements IEqualityComparer(Of C)
+    Private Function Equals(obj1 As C, obj2 As C) As Boolean Implements IEqualityComparer(Of C).Equals
+        Throw New Exception()
+    End Function
+    Private Function GetHashCode(obj As C) As Integer Implements IEqualityComparer(Of C).GetHashCode
+        Throw New Exception()
+    End Function
+End Class
 ";
 
             await VerifyVB.VerifyAnalyzerAsync(code,