Allow intercepting enums from other projects (#106)

* Add interceptable attribute

* Add additional interceptors and unit test

* Add integration tests

NetEscapades.EnumGenerators.sln

@@ -19,8 +19,6 @@ Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "_build", "build\_build.cspr
 EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "NetEscapades.EnumGenerators.Benchmarks", "tests\NetEscapades.EnumGenerators.Benchmarks\NetEscapades.EnumGenerators.Benchmarks.csproj", "{C7CFC4AC-BC5B-4F07-BE93-4F245D5547D9}"
 EndProject
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "NetEscapades.EnumGenerators.Attributes", "src\NetEscapades.EnumGenerators.Attributes\NetEscapades.EnumGenerators.Attributes.csproj", "{8B6E63F3-EB6A-4A72-86B1-A49E53C62305}"
-EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "NetEscapades.EnumGenerators.Nuget.Attributes.IntegrationTests", "tests\NetEscapades.EnumGenerators.Nuget.Attributes.IntegrationTests\NetEscapades.EnumGenerators.Nuget.Attributes.IntegrationTests.csproj", "{E7D66FE9-65BC-4DC8-AC86-5C5BE10D8E61}"
 EndProject
 Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "samples", "samples", "{AC0DDDB0-385D-43B8-A770-C79EE2077D05}"
@@ -41,6 +39,14 @@ Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "NetEscapades.EnumGenerators
 EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "NetEscapades.EnumGenerators.Interceptors.IntegrationTests", "tests\NetEscapades.EnumGenerators.Interceptors.IntegrationTests\NetEscapades.EnumGenerators.Interceptors.IntegrationTests.csproj", "{E390E06A-27EE-49B3-9113-37812B92060A}"
 EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "NetEscapades.EnumGenerators.NetStandard.Interceptors.IntegrationTests", "tests\NetEscapades.EnumGenerators.NetStandard.Interceptors.IntegrationTests\NetEscapades.EnumGenerators.NetStandard.Interceptors.IntegrationTests.csproj", "{B7C9B52C-94C5-4729-9C5E-F49B3A112130}"
+EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "NetEscapades.EnumGenerators.Attributes", "src\NetEscapades.EnumGenerators.Attributes\NetEscapades.EnumGenerators.Attributes.csproj", "{EA85D7C6-8691-47B9-92D1-DCDA98E16D02}"
+EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "NetEscapades.EnumGenerators.Nuget.NetStandard", "tests\NetEscapades.EnumGenerators.Nuget.NetStandard\NetEscapades.EnumGenerators.Nuget.NetStandard.csproj", "{0011A3F4-BBFC-40CE-B8A3-A23FDAC60DE7}"
+EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "NetEscapades.EnumGenerators.Nuget.NetStandard.Interceptors.IntegrationTests", "tests\NetEscapades.EnumGenerators.Nuget.NetStandard.Interceptors.IntegrationTests\NetEscapades.EnumGenerators.Nuget.NetStandard.Interceptors.IntegrationTests.csproj", "{99AC1B59-04D1-4B19-957B-D7DE4D19A7CD}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -70,10 +76,6 @@ Global
 		{C7CFC4AC-BC5B-4F07-BE93-4F245D5547D9}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{C7CFC4AC-BC5B-4F07-BE93-4F245D5547D9}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{C7CFC4AC-BC5B-4F07-BE93-4F245D5547D9}.Release|Any CPU.Build.0 = Release|Any CPU
-		{8B6E63F3-EB6A-4A72-86B1-A49E53C62305}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{8B6E63F3-EB6A-4A72-86B1-A49E53C62305}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{8B6E63F3-EB6A-4A72-86B1-A49E53C62305}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{8B6E63F3-EB6A-4A72-86B1-A49E53C62305}.Release|Any CPU.Build.0 = Release|Any CPU
 		{E7D66FE9-65BC-4DC8-AC86-5C5BE10D8E61}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
 		{E7D66FE9-65BC-4DC8-AC86-5C5BE10D8E61}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{BDF8C04B-D0E3-4FF5-82C3-E8FDF3916C16}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
@@ -106,14 +108,25 @@ Global
 		{E390E06A-27EE-49B3-9113-37812B92060A}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{E390E06A-27EE-49B3-9113-37812B92060A}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{E390E06A-27EE-49B3-9113-37812B92060A}.Release|Any CPU.Build.0 = Release|Any CPU
+		{B7C9B52C-94C5-4729-9C5E-F49B3A112130}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{B7C9B52C-94C5-4729-9C5E-F49B3A112130}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{B7C9B52C-94C5-4729-9C5E-F49B3A112130}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{B7C9B52C-94C5-4729-9C5E-F49B3A112130}.Release|Any CPU.Build.0 = Release|Any CPU
+		{EA85D7C6-8691-47B9-92D1-DCDA98E16D02}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{EA85D7C6-8691-47B9-92D1-DCDA98E16D02}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{EA85D7C6-8691-47B9-92D1-DCDA98E16D02}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{EA85D7C6-8691-47B9-92D1-DCDA98E16D02}.Release|Any CPU.Build.0 = Release|Any CPU
+		{0011A3F4-BBFC-40CE-B8A3-A23FDAC60DE7}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{0011A3F4-BBFC-40CE-B8A3-A23FDAC60DE7}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{99AC1B59-04D1-4B19-957B-D7DE4D19A7CD}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{99AC1B59-04D1-4B19-957B-D7DE4D19A7CD}.Release|Any CPU.ActiveCfg = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(NestedProjects) = preSolution
 		{FC6F4934-4512-45DB-ABDA-5FAD96742B73} = {78D56637-F921-437D-A9AC-FBEAD78344BE}
 		{443BC4C1-CF11-45E3-B772-72F886826C69} = {FF6F43E8-36EA-4BF0-9B2E-8ACC91C5F939}
 		{F03831B0-630E-4B0E-BD25-AFE975B35E69} = {FF6F43E8-36EA-4BF0-9B2E-8ACC91C5F939}
 		{328EFEB4-1D15-453E-9929-6FD0FACF3512} = {FF6F43E8-36EA-4BF0-9B2E-8ACC91C5F939}
 		{C7CFC4AC-BC5B-4F07-BE93-4F245D5547D9} = {FF6F43E8-36EA-4BF0-9B2E-8ACC91C5F939}
-		{8B6E63F3-EB6A-4A72-86B1-A49E53C62305} = {78D56637-F921-437D-A9AC-FBEAD78344BE}
 		{E7D66FE9-65BC-4DC8-AC86-5C5BE10D8E61} = {FF6F43E8-36EA-4BF0-9B2E-8ACC91C5F939}
 		{BDF8C04B-D0E3-4FF5-82C3-E8FDF3916C16} = {AC0DDDB0-385D-43B8-A770-C79EE2077D05}
 		{40B2D8D1-7523-498D-9753-CECC3A44071A} = {FF6F43E8-36EA-4BF0-9B2E-8ACC91C5F939}
@@ -123,5 +136,9 @@ Global
 		{3B52B2FC-007D-4CEE-9EF8-20E94F762850} = {FF6F43E8-36EA-4BF0-9B2E-8ACC91C5F939}
 		{F8B8BAC8-5F2D-42DE-8234-16C8C1D11520} = {78D56637-F921-437D-A9AC-FBEAD78344BE}
 		{E390E06A-27EE-49B3-9113-37812B92060A} = {FF6F43E8-36EA-4BF0-9B2E-8ACC91C5F939}
+		{B7C9B52C-94C5-4729-9C5E-F49B3A112130} = {FF6F43E8-36EA-4BF0-9B2E-8ACC91C5F939}
+		{EA85D7C6-8691-47B9-92D1-DCDA98E16D02} = {78D56637-F921-437D-A9AC-FBEAD78344BE}
+		{0011A3F4-BBFC-40CE-B8A3-A23FDAC60DE7} = {FF6F43E8-36EA-4BF0-9B2E-8ACC91C5F939}
+		{99AC1B59-04D1-4B19-957B-D7DE4D19A7CD} = {FF6F43E8-36EA-4BF0-9B2E-8ACC91C5F939}
 	EndGlobalSection
 EndGlobal

build/Build.cs

@@ -109,6 +109,7 @@ class Build : NukeBuild
                 Solution.tests.NetEscapades_EnumGenerators_Nuget_IntegrationTests.Path,
                 Solution.tests.NetEscapades_EnumGenerators_Nuget_Attributes_IntegrationTests.Path,
                 Solution.tests.NetEscapades_EnumGenerators_Nuget_Interceptors_IntegrationTests.Path,
+                Solution.tests.NetEscapades_EnumGenerators_Nuget_NetStandard_Interceptors_IntegrationTests.Path,
             };
 
             if (!string.IsNullOrEmpty(PackagesDirectory))

src/NetEscapades.EnumGenerators.Attributes/InterceptableAttribute.cs

@@ -0,0 +1,29 @@
+namespace NetEscapades.EnumGenerators
+{
+    /// <summary>
+    /// Add to an assembly to indicate that usages of the enum should
+    /// be automatically intercepted to use the extension methods
+    /// generated by <see cref="EnumExtensionsAttribute"/> in this project.
+    /// Note that the extension methods must be accessible from this project,
+    /// otherwise you will receive compilation errors
+    /// </summary>
+    [System.AttributeUsage(System.AttributeTargets.Assembly, AllowMultiple = true)]
+    [System.Diagnostics.Conditional("NETESCAPADES_ENUMGENERATORS_USAGES")]
+    public class InterceptableAttribute<T> : System.Attribute
+        where T: System.Enum
+    {
+        /// <summary>
+        /// The namespace generated for the extension class.
+        /// If not provided, the namespace of the enum will be assumed.
+        /// </summary>
+        public string? ExtensionClassNamespace { get; set; }
+
+        /// <summary>
+        /// The name used for the extension class.
+        /// If not provided, the enum name with ""Extensions"" will be assumed.
+        /// For example for an Enum called StatusCodes, the assumed name
+        /// will be StatusCodesExtensions.
+        /// </summary>
+        public string? ExtensionClassName { get; set; }
+    }
+}

src/NetEscapades.EnumGenerators/EnumGenerator.cs

@@ -15,6 +15,7 @@ public class EnumGenerator : IIncrementalGenerator
     private const string DescriptionAttribute = "System.ComponentModel.DescriptionAttribute";
     private const string EnumExtensionsAttribute = "NetEscapades.EnumGenerators.EnumExtensionsAttribute";
     private const string ExternalEnumExtensionsAttribute = "NetEscapades.EnumGenerators.EnumExtensionsAttribute`1";
+    private const string InterceptableAttribute = "NetEscapades.EnumGenerators.InterceptableAttribute`1";
     private const string FlagsAttribute = "System.FlagsAttribute";
 
     public void Initialize(IncrementalGeneratorInitializationContext context)
@@ -25,7 +26,7 @@ public void Initialize(IncrementalGeneratorInitializationContext context)
         IncrementalValuesProvider<EnumToGenerate> enumsToGenerate = context.SyntaxProvider
             .ForAttributeWithMetadataName(
                 EnumExtensionsAttribute,
-                predicate: (node, _) => node is EnumDeclarationSyntax,
+                predicate: static (node, _) => node is EnumDeclarationSyntax,
                 transform: GetTypeToGenerate)
             .WithTrackingName(TrackingNames.InitialExtraction)
             .Where(static m => m is not null)
@@ -36,12 +37,12 @@ public void Initialize(IncrementalGeneratorInitializationContext context)
             .SyntaxProvider
             .ForAttributeWithMetadataName(
                 ExternalEnumExtensionsAttribute,
-                predicate: (node, _) => node is CompilationUnitSyntax,
-                transform: GetExternalTypeToGenerate)
+                predicate: static (node, _) => node is CompilationUnitSyntax,
+                transform: static (context1, ct) => GetEnumToGenerateFromGenericAssemblyAttribute(context1, ct, "EnumExtensionsAttribute", "EnumExtensions"))
             .Where(static m => m is not null)
             .SelectMany(static (m, _) => m!.Value)
             .WithTrackingName(TrackingNames.InitialExternalExtraction);
-        
+
         context.RegisterSourceOutput(enumsToGenerate,
             static (spc, enumToGenerate) => Execute(in enumToGenerate, spc));
 
@@ -62,6 +63,17 @@ public void Initialize(IncrementalGeneratorInitializationContext context)
             .WithTrackingName(TrackingNames.Settings);
 
 #if INTERCEPTORS
+        // TODO: add an analyzer for these for old roslyn
+        var interceptableEnums = context
+            .SyntaxProvider
+            .ForAttributeWithMetadataName(
+                InterceptableAttribute,
+                predicate: (node, _) => node is CompilationUnitSyntax,
+                transform: (context1, ct) => GetEnumToGenerateFromGenericAssemblyAttribute(context1, ct, "InterceptableAttribute", "Interceptable"))
+            .Where(static m => m is not null)
+            .SelectMany(static (m, _) => m!.Value)
+            .WithTrackingName(TrackingNames.InitialExternalExtraction);
+
         var interceptionEnabled = settings
             .Select((x, _) => x.Left && x.Right);
 
@@ -87,11 +99,20 @@ public void Initialize(IncrementalGeneratorInitializationContext context)
             .Where(x => x is not null)
             .WithTrackingName(TrackingNames.ExternalInterceptions);
 
+        var additionalInterceptions = interceptableEnums
+            .Combine(locations)
+            .Select(FilterInterceptorCandidates!)
+            .Where(x => x is not null)
+            .WithTrackingName(TrackingNames.AdditionalInterceptions);
+
         context.RegisterImplementationSourceOutput(enumInterceptions,
             static (spc, toIntercept) => ExecuteInterceptors(toIntercept, spc));
 
         context.RegisterImplementationSourceOutput(externalInterceptions,
             static (spc, toIntercept) => ExecuteInterceptors(toIntercept, spc));
+
+        context.RegisterImplementationSourceOutput(additionalInterceptions,
+            static (spc, toIntercept) => ExecuteInterceptors(toIntercept, spc));
 #endif
         context.RegisterImplementationSourceOutput(settings,
             static (spc, args) =>
@@ -119,13 +140,14 @@ static void Execute(in EnumToGenerate enumToGenerate, SourceProductionContext co
         context.AddSource(enumToGenerate.Name + "_EnumExtensions.g.cs", SourceText.From(result, Encoding.UTF8));    
     }
 
-    static EquatableArray<EnumToGenerate>? GetExternalTypeToGenerate(GeneratorAttributeSyntaxContext context, CancellationToken ct)
+    static EquatableArray<EnumToGenerate>? GetEnumToGenerateFromGenericAssemblyAttribute(
+        GeneratorAttributeSyntaxContext context, CancellationToken ct, string fullAttributeName, string shortAttributeName)
     {
         List<EnumToGenerate>? enums = null;
         foreach (AttributeData attribute in context.Attributes)
         {
-            if (!((attribute.AttributeClass?.Name == "EnumExtensionsAttribute" ||
-                   attribute.AttributeClass?.Name == "EnumExtensions") &&
+            if (!((attribute.AttributeClass?.Name == fullAttributeName ||
+                   attribute.AttributeClass?.Name == shortAttributeName) &&
                   attribute.AttributeClass.IsGenericType &&
                   attribute.AttributeClass.TypeArguments.Length == 1))
             {

src/NetEscapades.EnumGenerators/SourceGenerationHelper.cs

@@ -92,6 +92,38 @@ public class EnumExtensionsAttribute<T> : System.Attribute
         /// </summary>
         public bool IsInterceptable { get; set; } = true;
     }
+
+    /// <summary>
+    /// Add to an assembly to indicate that usages of the enum should
+    /// be automatically intercepted to use the extension methods
+    /// generated by <see cref=""EnumExtensionsAttribute""/> in this project.
+    /// Note that the extension methods must be accessible from this project,
+    /// otherwise you will receive compilation errors
+    /// </summary>
+    [global::System.AttributeUsage(global::System.AttributeTargets.Assembly, AllowMultiple = true)]
+    [global::System.Diagnostics.Conditional(""NETESCAPADES_ENUMGENERATORS_USAGES"")]
+#if NET5_0_OR_GREATER
+    [global::System.Diagnostics.CodeAnalysis.ExcludeFromCodeCoverage(Justification = ""Generated by the NetEscapades.EnumGenerators source generator."")]
+#else
+    [global::System.Diagnostics.CodeAnalysis.ExcludeFromCodeCoverage]
+#endif
+    public class InterceptableAttribute<T> : global::System.Attribute
+        where T: global::System.Enum
+    {
+        /// <summary>
+        /// The namespace generated for the extension class.
+        /// If not provided, the namespace of the enum will be assumed.
+        /// </summary>
+        public string? ExtensionClassNamespace { get; set; }
+
+        /// <summary>
+        /// The name used for the extension class.
+        /// If not provided, the enum name with """"Extensions"""" will be assumed.
+        /// For example for an Enum called StatusCodes, the assumed name
+        /// will be StatusCodesExtensions.
+        /// </summary>
+        public string? ExtensionClassName { get; set; }
+    }
 }
 #endif
 ";

src/NetEscapades.EnumGenerators/TrackingNames.cs

@@ -7,9 +7,11 @@ public class TrackingNames
 {
     public const string InitialExtraction = nameof(InitialExtraction);
     public const string InitialExternalExtraction = nameof(InitialExternalExtraction);
+    public const string InitialInterceptable = nameof(InitialInterceptable);
     public const string RemovingNulls = nameof(RemovingNulls);
     public const string InterceptedLocations = nameof(InterceptedLocations);
     public const string Settings = nameof(Settings);
     public const string EnumInterceptions = nameof(EnumInterceptions);
     public const string ExternalInterceptions = nameof(ExternalInterceptions);
+    public const string AdditionalInterceptions = nameof(AdditionalInterceptions);
 }

tests/NetEscapades.EnumGenerators.IntegrationTests/Enums.cs

@@ -16,6 +16,14 @@ public enum EnumInSystem
         Second = 1,
         Third = 2,
     }
+
+    [EnumExtensions(IsInterceptable = false)]
+    public enum NonInterceptableEnum
+    {
+        First = 0,
+        [Display(Name = "2nd")] Second = 1,
+        Third = 2,
+    }
 }
 
 namespace Foo
@@ -33,6 +41,7 @@ public class Foo
     public enum EnumInFoo
     {
         First = 0,
+        [Display(Name = "2nd")]
         Second = 1,
         Third = 2,
     }
@@ -51,6 +60,8 @@ namespace NetEscapades.EnumGenerators.Nuget.Attributes.IntegrationTests
 namespace NetEscapades.EnumGenerators.Nuget.IntegrationTests
 #elif NUGET_INTERCEPTOR_TESTS
 namespace NetEscapades.EnumGenerators.Nuget.Interceptors.IntegrationTests
+#elif NUGET_NETSTANDARD_INTERCEPTOR_TESTS
+namespace NetEscapades.EnumGenerators.Nuget.NetStandard.Interceptors.IntegrationTests
 #else
 #error Unknown integration tests
 #endif
@@ -109,18 +120,30 @@ public enum LongEnum: long
     [Flags]
     public enum FlagsEnum
     {
+        None = 0,
         First = 1 << 0,
         Second = 1 << 1,
         Third = 1 << 2,
         Fourth = 1 << 3,
         ThirdAndFourth = Third | Fourth,
     }
 
+    [EnumExtensions]
     public enum StringTesting
     {
         [System.ComponentModel.Description("Quotes \"")]   Quotes,
         [System.ComponentModel.Description(@"Literal Quotes """)]   LiteralQuotes,
         [System.ComponentModel.Description("Backslash \\")]   Backslash,
         [System.ComponentModel.Description(@"LiteralBackslash \")]   BackslashLiteral,
     }
+
+    [EnumExtensions(ExtensionClassName="SomeExtension", ExtensionClassNamespace = "SomethingElse")]
+    public enum EnumWithExtensionInOtherNamespace
+    {
+        First = 0,
+
+        [Display(Name = "2nd")] Second = 1,
+
+        Third = 2,
+    }
 }