Add generator attribute source

src/BlueWest.MapTo/Sources/EfMethods/EfGeneratorAttributeSource.cs

@@ -0,0 +1,41 @@
+using static MapTo.Sources.Constants;
+
+namespace MapTo.Sources
+{
+    public class EfGeneratorAttributeSource
+    {
+        internal const string AttributeName = "EfGenerator";
+        internal const string AttributeClassName = AttributeName + "Attribute";
+        internal const string FullyQualifiedName = RootNamespace + "." + AttributeClassName;
+        
+        internal static SourceCode Generate(SourceGenerationOptions options)
+        {
+            using var builder = new SourceBuilder()
+                .WriteLine(GeneratedFilesHeader)
+                .WriteLine("using System;")
+                .WriteLine()
+                .WriteLine($"namespace {RootNamespace}")
+                .WriteOpeningBracket();
+
+            if (options.GenerateXmlDocument)
+            {
+                builder
+                    .WriteLine("/// <summary>")
+                    .WriteLine("/// Generate Add methods for interacting with the entity")
+                    .WriteLine("/// </summary>");
+            }
+
+            builder
+                .WriteLine("[AttributeUsage(AttributeTargets.Class)]")
+                .WriteLine($"public sealed class {AttributeName}Attribute : Attribute")
+                .WriteOpeningBracket()
+                .WriteLine();
+
+            builder
+                .WriteClosingBracket() // class
+                .WriteClosingBracket(); // namespace
+
+            return new(builder.ToString(), $"{AttributeName}Attribute.g.cs");
+        }
+    }
+}

src/BlueWest.MapTo/Sources/EfMethods/EfGeneratorExtensionMethods.cs

@@ -0,0 +1,77 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using MapTo.Extensions;
+using Microsoft.CodeAnalysis;
+using Microsoft.CodeAnalysis.CSharp.Syntax;
+
+namespace MapTo.Sources.EfMethods
+{
+    public static class EfGeneratorExtensionMethods
+    {
+         public static void InitializeEfGenerator(this ISourceGenerator sourceGenerator, GeneratorInitializationContext context)
+        {
+            context.RegisterForSyntaxNotifications(() => new EfMethodsSyntaxReceiver());
+        }
+
+        /// <inheritdoc />
+        public static void ExecuteEfGenerator(this ISourceGenerator sourceGenerator, GeneratorExecutionContext context)
+        {
+            try
+            {
+                var options = SourceGenerationOptions.From(context);
+
+                var compilation = context.Compilation
+                    .AddSource(ref context, EfAddMethodsAttributeSource.Generate(options))
+                    .AddSource(ref context, EfUpdateMethodsAttributeSource.Generate(options));
+                
+
+                if (context.SyntaxReceiver is EfMethodsSyntaxReceiver receiver && receiver.CandidateMembers.Any())
+                {
+                    AddGeneratedExtensions(context, compilation, receiver.CandidateMembers, options);
+                }
+            }
+            catch (Exception ex)
+            {
+                Console.WriteLine(ex);
+                throw;
+            }
+        }
+
+        private  static void AddGeneratedExtensions( GeneratorExecutionContext context, Compilation compilation, IEnumerable<CandidateMember> candidateMembers, SourceGenerationOptions options)
+        {
+            //SpinWait.SpinUntil(() => Debugger.IsAttached);
+            
+            foreach (var candidateMember in candidateMembers)
+            {
+                string addSourceTemplate = context.AdditionalFiles
+                        .FirstOrDefault(x => x.Path.Contains("AddToEntityTemplate"))?
+                        .GetText()?
+                        .ToString() ?? string.Empty;
+
+                string updateSourceTemplate = context.AdditionalFiles
+                        .FirstOrDefault(x => x.Path.Contains("UpdateEntityTemplate"))?
+                        .GetText()?
+                        .ToString() ?? string.Empty;
+
+
+                var mappingContext = EfGeneratorContext.Create(compilation, options, candidateMember.MemberDeclarationSyntax);
+                
+                mappingContext.Diagnostics.ForEach(context.ReportDiagnostic);
+                
+                if (mappingContext.Model is null)
+                {
+                    continue;
+                }
+                
+                var (source, hintName) = candidateMember.MemberDeclarationSyntax switch
+                {
+                    PropertyDeclarationSyntax => EfMethodsSource.Generate(mappingContext.Model, addSourceTemplate, updateSourceTemplate),
+                    _ => throw new ArgumentOutOfRangeException()
+                };
+
+                context.AddSource(hintName, source);
+            }
+        }
+    }
+}

src/BlueWest.MapTo/Sources/EfMethods/EfMethodsGenerator.cs

@@ -30,6 +30,7 @@ namespace MapTo
                 var options = SourceGenerationOptions.From(context);
 
                 var compilation = context.Compilation
+                    .AddSource(ref context, EfGeneratorAttributeSource.Generate(options))
                     .AddSource(ref context, EfAddMethodsAttributeSource.Generate(options))
                     .AddSource(ref context, EfUpdateMethodsAttributeSource.Generate(options));