Added enumeration predicates and conditions

src/NetArchTest.Rules/Conditions.cs

@@ -717,5 +717,25 @@ public ConditionList MeetCustomRule(ICustomRule rule)
             _sequence.AddFunctionCall(FunctionDelegates.MeetCustomRule, rule, true);
             return new ConditionList(_types, _should, _sequence);
         }
+
+        /// <summary>
+        /// Selects types that are enumerations.
+        /// </summary>
+        /// <returns>An updated set of conditions that can be applied to a list of types.</returns>
+        public ConditionList BeEnums()
+        {
+            _sequence.AddFunctionCall(FunctionDelegates.BeEnum, true, true);
+            return new ConditionList(_types, _should, _sequence);
+        }
+
+        /// <summary>
+        /// Selects types that are not enumerations.
+        /// </summary>
+        /// <returns>An updated set of conditions that can be applied to a list of types.</returns>
+        public ConditionList NotBeEnums()
+        {
+            _sequence.AddFunctionCall(FunctionDelegates.BeEnum, true, false);
+            return new ConditionList(_types, _should, _sequence);
+        }
     }
 }

src/NetArchTest.Rules/FunctionDelegates.cs

@@ -322,5 +322,14 @@ bool ClassIsStatic(TypeDefinition c) =>
             {
                 return input.Where(t => rule.MeetsRule(t) == condition);
             };
+
+        /// <summary>
+        /// Function for finding enumerations.
+        /// </summary>
+        internal static readonly FunctionDelegate<bool> BeEnum =
+            delegate (IEnumerable<TypeDefinition> input, bool dummy, bool condition)
+            {
+                return input.Where(c => c.IsEnum == condition);
+            };
     }
 }

src/NetArchTest.Rules/Predicates.cs

@@ -734,5 +734,25 @@ public PredicateList MeetCustomRule(ICustomRule rule)
             _sequence.AddFunctionCall(FunctionDelegates.MeetCustomRule, rule, true);
             return new PredicateList(_types, _sequence);
         }
+
+        /// <summary>
+        /// Selects types that are enumerations.
+        /// </summary>
+        /// <returns>An updated set of predicates that can be applied to a list of types.</returns>
+        public PredicateList AreEnums()
+        {
+            _sequence.AddFunctionCall(FunctionDelegates.BeEnum, true, true);
+            return new PredicateList(_types, _sequence);
+        }
+
+        /// <summary>
+        /// Selects types that are not enumerations.
+        /// </summary>
+        /// <returns>An updated set of predicates that can be applied to a list of types.</returns>
+        public PredicateList AreNotEnums()
+        {
+            _sequence.AddFunctionCall(FunctionDelegates.BeEnum, true, false);
+            return new PredicateList(_types, _sequence);
+        }
     }
 }

test/NetArchTest.Rules.UnitTests/ConditionTests.cs

@@ -984,5 +984,35 @@ public void MeetCustomRule_MatchesFound_ClassSelected()
             // The custom rule was executed at least once
             Assert.True(rule.TestMethodCalled);
         }
+
+        [Fact(DisplayName = "Types can be selected if they are enumerations.")]
+        public void AreEnums_MatchesFound_EnumsSelected()
+        {
+            var result = Types
+                .InAssembly(Assembly.GetAssembly(typeof(ClassA1)))
+                .That()
+                .ResideInNamespace("NetArchTest.TestStructure.Enumerations")
+                .And()
+                .DoNotHaveName("NoEnum")
+                .Should()
+                .BeEnums().GetResult();
+
+            Assert.True(result.IsSuccessful);
+        }
+
+        [Fact(DisplayName = "Types can be selected if they are not enumerations.")]
+        public void AreNotEnums_MatchesFound_EnumsSelected()
+        {
+            var result = Types
+                .InAssembly(Assembly.GetAssembly(typeof(ClassA1)))
+                .That()
+                .ResideInNamespace("NetArchTest.TestStructure.Enumerations")
+                .And()
+                .HaveName("NoEnum")
+                .Should()
+                .NotBeEnums().GetResult();
+
+            Assert.True(result.IsSuccessful);
+        }
     }
 }

test/NetArchTest.Rules.UnitTests/PredicateTests.cs

@@ -29,6 +29,7 @@ namespace NetArchTest.Rules.UnitTests
     using Xunit;
     using NetArchTest.TestStructure.Nullable;
     using NetArchTest.TestStructure.Dependencies.Examples;
+    using NetArchTest.TestStructure.Enumerations;
 
     public class PredicateTests
     {
@@ -1096,5 +1097,34 @@ public void GetResult_Doesnt_Evaluate_Twice()
 
             Assert.True(customRule.TimesTimesCalled == 1);
         }
+
+        [Fact(DisplayName = "Types can be selected if they are enumerations.")]
+        public void AreEnums_MatchesFound_EnumsSelected()
+        {
+            var result = Types
+                .InAssembly(Assembly.GetAssembly(typeof(ClassA1)))
+                .That()
+                .ResideInNamespace("NetArchTest.TestStructure.Enumerations")
+                .And()
+                .AreEnums().GetTypes();
+
+            Assert.Equal(2, result.Count()); // Two types found
+            Assert.Contains<Type>(typeof(ExampleEnum), result);
+            Assert.Contains<Type>(typeof(FlagEnum), result);
+        }
+
+        [Fact(DisplayName = "Types can be selected if they are not enumerations.")]
+        public void AreNotEnums_MatchesFound_EnumsSelected()
+        {
+            var result = Types
+                .InAssembly(Assembly.GetAssembly(typeof(ClassA1)))
+                .That()
+                .ResideInNamespace("NetArchTest.TestStructure.Enumerations")
+                .And()
+                .AreNotEnums().GetTypes();
+
+            Assert.Single(result); // One type found
+            Assert.Contains<Type>(typeof(NoEnum), result);
+        }
     }
 }

test/NetArchTest.TestStructure/Enumerations/ExampleEnum.cs

@@ -0,0 +1,6 @@
+namespace NetArchTest.TestStructure.Enumerations
+{
+    public enum ExampleEnum
+    {
+    }
+}

test/NetArchTest.TestStructure/Enumerations/FlagEnum.cs

@@ -0,0 +1,9 @@
+using System;
+
+namespace NetArchTest.TestStructure.Enumerations
+{
+    [Flags]
+    public enum FlagEnum
+    {
+    }
+}

test/NetArchTest.TestStructure/Enumerations/NoEnum.cs

@@ -0,0 +1,6 @@
+namespace NetArchTest.TestStructure.Enumerations
+{
+    public class NoEnum
+    {
+    }
+}