Add tests for and fix bugs in AccessLevelHelper.CombineEffectiveAccessibility

Author: sharwell

StyleCop.Analyzers/StyleCop.Analyzers.Test/HelperTests/AccessLevelHelperTests.cs

@@ -0,0 +1,45 @@
+// Copyright (c) Tunnel Vision Laboratories, LLC. All Rights Reserved.
+// Licensed under the Apache License, Version 2.0. See LICENSE in the project root for license information.
+
+namespace StyleCop.Analyzers.Test.HelperTests
+{
+    using Analyzers.Helpers;
+    using Microsoft.CodeAnalysis;
+    using Xunit;
+
+    public class AccessLevelHelperTests
+    {
+        [Fact]
+        public void TestCombineEffectiveAccessibility()
+        {
+            // If enclosing is private, declared does not matter
+            Assert.Equal(Accessibility.Private, AccessLevelHelper.CombineEffectiveAccessibility(Accessibility.NotApplicable, Accessibility.Private));
+            Assert.Equal(Accessibility.Private, AccessLevelHelper.CombineEffectiveAccessibility(Accessibility.Private, Accessibility.Private));
+            Assert.Equal(Accessibility.Private, AccessLevelHelper.CombineEffectiveAccessibility(Accessibility.Internal, Accessibility.Private));
+            Assert.Equal(Accessibility.Private, AccessLevelHelper.CombineEffectiveAccessibility(Accessibility.Protected, Accessibility.Private));
+            Assert.Equal(Accessibility.Private, AccessLevelHelper.CombineEffectiveAccessibility(Accessibility.Public, Accessibility.Private));
+
+            // Test enclosing is ProtectedAndInternal
+            Assert.Equal(Accessibility.Private, AccessLevelHelper.CombineEffectiveAccessibility(Accessibility.Private, Accessibility.ProtectedAndInternal));
+            Assert.Equal(Accessibility.ProtectedAndInternal, AccessLevelHelper.CombineEffectiveAccessibility(Accessibility.Public, Accessibility.ProtectedAndInternal));
+
+            // Test enclosing is Protected
+            Assert.Equal(Accessibility.Private, AccessLevelHelper.CombineEffectiveAccessibility(Accessibility.Private, Accessibility.Protected));
+            Assert.Equal(Accessibility.ProtectedAndInternal, AccessLevelHelper.CombineEffectiveAccessibility(Accessibility.Internal, Accessibility.Protected));
+            Assert.Equal(Accessibility.Protected, AccessLevelHelper.CombineEffectiveAccessibility(Accessibility.Public, Accessibility.Protected));
+
+            // Test enclosing is Internal
+            Assert.Equal(Accessibility.Private, AccessLevelHelper.CombineEffectiveAccessibility(Accessibility.Private, Accessibility.Internal));
+            Assert.Equal(Accessibility.ProtectedAndInternal, AccessLevelHelper.CombineEffectiveAccessibility(Accessibility.Protected, Accessibility.Internal));
+            Assert.Equal(Accessibility.Internal, AccessLevelHelper.CombineEffectiveAccessibility(Accessibility.Public, Accessibility.Internal));
+
+            // Test enclosing is ProtectedOrInternal
+            Assert.Equal(Accessibility.Private, AccessLevelHelper.CombineEffectiveAccessibility(Accessibility.Private, Accessibility.ProtectedOrInternal));
+            Assert.Equal(Accessibility.ProtectedOrInternal, AccessLevelHelper.CombineEffectiveAccessibility(Accessibility.Public, Accessibility.ProtectedOrInternal));
+
+            // Test enclosing is Public
+            Assert.Equal(Accessibility.Private, AccessLevelHelper.CombineEffectiveAccessibility(Accessibility.Private, Accessibility.Public));
+            Assert.Equal(Accessibility.Public, AccessLevelHelper.CombineEffectiveAccessibility(Accessibility.Public, Accessibility.Public));
+        }
+    }
+}

StyleCop.Analyzers/StyleCop.Analyzers.Test/StyleCop.Analyzers.Test.csproj

@@ -170,6 +170,7 @@
     <Compile Include="Helpers\DiagnosticVerifier.Helper.cs" />
     <Compile Include="Helpers\ExclusionTestAnalyzer.cs" />
     <Compile Include="Helpers\TestDiagnosticProvider.cs" />
+    <Compile Include="HelperTests\AccessLevelHelperTests.cs" />
     <Compile Include="HelperTests\TokenHelperTests.cs" />
     <Compile Include="HelperTests\TriviaHelperTests.cs" />
     <Compile Include="LayoutRules\SA1500\SA1500UnitTests.Blocks.cs" />

StyleCop.Analyzers/StyleCop.Analyzers/Helpers/AccessLevelHelper.cs

@@ -503,9 +503,11 @@ internal static Accessibility CombineEffectiveAccessibility(Accessibility declar
                 {
                 case Accessibility.NotApplicable:
                 case Accessibility.Private:
+                    return declaredAccessibility;
+
                 case Accessibility.ProtectedAndInternal:
                 case Accessibility.Internal:
-                    return declaredAccessibility;
+                    return Accessibility.ProtectedAndInternal;
 
                 case Accessibility.Protected:
                 case Accessibility.ProtectedOrInternal:
@@ -519,9 +521,9 @@ internal static Accessibility CombineEffectiveAccessibility(Accessibility declar
                 {
                 case Accessibility.NotApplicable:
                 case Accessibility.Private:
-                case Accessibility.ProtectedAndInternal:
                     return declaredAccessibility;
 
+                case Accessibility.ProtectedAndInternal:
                 case Accessibility.Protected:
                     return Accessibility.ProtectedAndInternal;
 
@@ -545,7 +547,7 @@ internal static Accessibility CombineEffectiveAccessibility(Accessibility declar
 
                 case Accessibility.Public:
                 default:
-                    return Accessibility.Public;
+                    return Accessibility.ProtectedOrInternal;
                 }
 
             case Accessibility.Public: