Add factory method for GUIDs

docs/site/Writerside/topics/how-to/Testing.md

@@ -14,9 +14,9 @@ So the tests are in two solutions:
 
 * In the **main solution**, there are [snapshot tests](https://github.com/VerifyTests/Verify) which create **in-memory projects** that exercise the generators using different versions of the .NET Framework.
 These are slow to run because they use many different permutations of features and dozens of variations of configuration/primitive-type/C#-type/accessibility-type/converters, for example:
-    * does it correctly generate a record struct with instances and normalization and a type converter and a Dapper serializer
-    * does it correctly generate a class with no converters, no validation, and no serialization
-    * does it correctly generate a readonly struct with a LinqToDb converter
+    * does it correctly generate a record struct with instances and normalization and a type converter and a Dapper serializer?
+    * does it correctly generate a class with no converters, no validation, and no serialization?
+    * does it correctly generate a readonly struct with a LinqToDb converter?
     * etc. etc.
 
     (all tests run for each supported framework)
@@ -30,7 +30,7 @@ The snapshot tests in the IDE run in about 5 minutes. In the CI build, we set a
   These tests are much quicker to run.
   They verify the behavior
  of created Value Objects, such as:
-    * [Normalization](https://github.com/SteveDunn/Vogen/wiki/Normalization)
+    * [Normalization](NormalizationHowTo.md "How to use normalization")
     * Equality
     * Hashing
     * ToString

docs/site/Writerside/topics/reference/Configuration.md

@@ -8,22 +8,23 @@ This topic is incomplete and is currently being improved.
 Each Value Object can have its own *optional* configuration. Configuration includes:
 
 * The underlying type
-* Any 'conversions' (Dapper, System.Text.Json, Newtonsoft.Json, etc.) - see [the Integrations page](https://github.com/SteveDunn/Vogen/wiki/Integration) in the wiki for more information
+* Any 'conversions' (Dapper, System.Text.Json, Newtonsoft.Json, etc.) - see Integrations in the wiki for more information
 * The type of the exception that is thrown when validation fails
 
 If any of those above are not specified, then global configuration is inferred. It looks like this:
 
 ```c#
-[assembly: VogenDefaults(underlyingType: typeof(int), conversions: Conversions.Default, throws: typeof(ValueObjectValidationException))]
+[assembly: VogenDefaults(
+    underlyingType: typeof(int), 
+    conversions: Conversions.Default, 
+    throws: typeof(ValueObjectValidationException))]
 ```
 
-Those again are optional. If they're not specified, then they are defaulted to:
-
 * Underlying type = `typeof(int)`
-* Conversions = `Conversions.Default` (`TypeConverter` and `System.Text.Json`)
-* Validation exception type = `typeof(ValueObjectValidationException)`
+* Conversions = `Conversions.Default` which is `TypeConverter` and `System.Text.Json`
+* Validation exception type = which is `ValueObjectValidationException`
 
-There are several code analysis warnings for invalid configuration, including:
+Several code analysis warnings exist for invalid configuration, including:
 
 * when you specify an exception that does not derive from `System.Exception`
 * when your exception does not have one public constructor that takes an int

docs/site/Writerside/topics/reference/FAQ.md

@@ -43,8 +43,7 @@ correct.
 ## How do I identify types that are generated by Vogen?
 _I'd like to be able to identify types that are generated by Vogen so that I can integrate them in things like EFCore._
 
-**A: ** You can use this information on [this page](How-to-identify-a-type-that-is-generated-by-Vogen.md)
-
+This is described in [this how-to page](How-to-identify-a-type-that-is-generated-by-Vogen.md)
 
 ### What versions of .NET are supported?
 
@@ -325,20 +324,14 @@ Yes, add NormalizeInput method, e.g.
 ```c#
     private static string NormalizeInput(string input) => input.Trim();
 ```
-See [wiki](https://github.com/SteveDunn/Vogen/wiki/Normalization) for more information.
+See [the how-to page](NormalizationHowTo.md) for more information.
 
 
 ### Can I create custom Value Object attributes with my own defaults?
 
-Yes, but (at the moment) it requires that you put your defaults in your attribute's constructor—not in the call to
-the base class' constructor (see [this comment](https://github.com/SteveDunn/Vogen/pull/321#issuecomment-1399324832)).
-
-```c#
-public class CustomValueObjectAttribute : ValueObjectAttribute<long>
-{
-    // This attribute will default to having both the default conversions and EF Core type conversions
-    public CustomValueObjectAttribute(Conversions conversions = Conversions.Default | Conversions.EfCoreValueConverter) { }
-}
+No. It used to be possible, but it impacts the performance of Vogen.
+A much better way is
+to use [type alias feature C# 12](https://learn.microsoft.com/en-us/dotnet/csharp/language-reference/proposals/csharp-12.0/using-alias-types).
 ```
 
 NOTE: *custom attributes must extend a ValueObjectAttribute class; you cannot layer custom attributes on top of each other*
@@ -470,3 +463,19 @@ The BoxId type will now be serialized as a `string` in all messages and grpc cal
 for other applications from C#, proto files will include the `Surrogate` type as the type.
 
 _thank you to [@DomasM](https://github.com/DomasM) for this information_.
+
+### Can I have a factory method for value objects that wrap GUIDs?
+
+Yes, use the `Customizations.AddFactoryMethodForGuids` in the global config attribute, e.g.
+
+```c#
+[assembly: VogenDefaults(
+  customizations: Customizations.AddFactoryMethodForGuids)]
+
+[ValueObject<Guid>]
+public partial {{type}} CustomerId { }
+
+...
+
+var newCustomerId = CustomerId.FromNewGuid();
+```

src/Vogen.SharedTypes/Customizations.cs

@@ -3,8 +3,8 @@
 namespace Vogen;
 
 /// <summary>
-/// Customization flags. For things like treating doubles as strings
-/// during [de]serialization (for compatibility with JavaScript).
+/// Customization flags. For simple binary choices.
+/// More complex configuration options are specified as parameters in the <see cref="VogenDefaultsAttribute"/>.
 /// </summary>
 [Flags]
 public enum Customizations
@@ -17,10 +17,15 @@ public enum Customizations
     None = 0,
 
     /// <summary>
-    /// When [de]serializing an underlying primitive that wold normally be written as a number in System.Text.Json,
+    /// When [de]serializing an underlying primitive that would normally be written as a number in System.Text.Json,
     /// instead, treat the underlying primitive as a culture invariant string. This gets around the issue of
     /// JavaScript losing precision on very large numbers. See <see href="https://github.com/SteveDunn/Vogen/issues/165"/>
     /// for more information.
     /// </summary>
-    TreatNumberAsStringInSystemTextJson = 1 << 0
+    TreatNumberAsStringInSystemTextJson = 1 << 0,
+
+    /// <summary>
+    /// For GUIDs, add a `FromNewGuid()` factory method, which is just `public static MyVo FromNewGuid() => From(Guid.NewGuid());`
+    /// </summary>
+    AddFactoryMethodForGuids = 1 << 1
 }

src/Vogen/Generators/ClassGenerator.cs

@@ -99,7 +99,7 @@ public string BuildClass(VoWorkItem item, TypeDeclarationSyntax tds)
         public static global::System.Boolean operator ==({itemUnderlyingType} left, {className} right) => Equals(left, right.Value);
         public static global::System.Boolean operator !=({itemUnderlyingType} left, {className} right) => !Equals(left, right.Value);
 
-{GenerateCastingOperators.Generate(item,tds)}
+{GenerateCastingOperators.Generate(item,tds)}{Util.GenerateGuidFactoryMethodIfRequired(item, tds)}
         {GenerateComparableCode.GenerateIComparableImplementationIfNeeded(item, tds)}
 
         {GenerateCodeForTryParse.GenerateAnyHoistedTryParseMethods(item)}{GenerateCodeForParse.GenerateAnyHoistedParseMethods(item)}

src/Vogen/Generators/RecordClassGenerator.cs

@@ -106,7 +106,7 @@ public string BuildClass(VoWorkItem item, TypeDeclarationSyntax tds)
         public static global::System.Boolean operator ==({itemUnderlyingType} left, {className} right) => Equals(left, right.Value);
         public static global::System.Boolean operator !=({itemUnderlyingType} left, {className} right) => !Equals(left, right.Value);
 
-{GenerateCastingOperators.Generate(item,tds)}
+{GenerateCastingOperators.Generate(item,tds)}{Util.GenerateGuidFactoryMethodIfRequired(item, tds)}
         {GenerateComparableCode.GenerateIComparableImplementationIfNeeded(item, tds)}
 
         {GenerateCodeForTryParse.GenerateAnyHoistedTryParseMethods(item)}{GenerateCodeForParse.GenerateAnyHoistedParseMethods(item)}

src/Vogen/Generators/RecordStructGenerator.cs

@@ -87,7 +87,7 @@ public readonly {itemUnderlyingType} Value
             return instance;
         }}
 {GenerateEqualsAndHashCodes.GenerateStringComparersIfNeeded(item, tds)}        
-{GenerateCastingOperators.Generate(item,tds)}
+{GenerateCastingOperators.Generate(item,tds)}{Util.GenerateGuidFactoryMethodIfRequired(item, tds)}
         // only called internally when something has been deserialized into
         // its primitive type.
         private static {structName} Deserialize({itemUnderlyingType} value)

src/Vogen/Generators/StructGenerator.cs

@@ -77,7 +77,7 @@ public readonly {itemUnderlyingType} Value
         }}
 {GenerateEqualsAndHashCodes.GenerateStringComparersIfNeeded(item, tds)}        
 
-{GenerateCastingOperators.Generate(item,tds)}
+{GenerateCastingOperators.Generate(item,tds)}{Util.GenerateGuidFactoryMethodIfRequired(item, tds)}
         // only called internally when something has been deserialized into
         // its primitive type.
         private static {structName} Deserialize({itemUnderlyingType} value)

src/Vogen/Util.cs

@@ -223,6 +223,16 @@ public static string GenerateToStringReadOnly(VoWorkItem item) =>
             $@"/// <summary>Returns the string representation of the underlying type</summary>
     /// <inheritdoc cref=""{item.UnderlyingTypeFullName}.ToString()"" />
     public readonly override global::System.String ToString() =>_isInitialized ? Value.ToString() : ""[UNINITIALIZED]"";";
+
+    public static string GenerateGuidFactoryMethodIfRequired(VoWorkItem item, TypeDeclarationSyntax tds)
+    {
+        if (item.UnderlyingTypeFullName == "System.Guid" && item.Customizations.HasFlag(Customizations.AddFactoryMethodForGuids))
+        {
+            return $"public static {item.VoTypeName} FromNewGuid() {{ return From(global::System.Guid.NewGuid()); }}";
+        }
+
+        return string.Empty;
+    }
 }
 
 public static class DebugGeneration

tests/SnapshotTests/GeneralStuff/GeneralTests.cs

@@ -8,6 +8,31 @@ namespace SnapshotTests.GeneralStuff;
 [UsesVerify]
 public class GeneralTests
 {
+    [Theory]
+    [InlineData("struct")]
+    [InlineData("class")]
+    [InlineData("record struct")]
+    [InlineData("record class")]
+    public async Task Can_specify_a_factory_method_for_wrappers_for_guids(string type)
+    {
+        var source = $$"""
+
+                     using System;
+                     using Vogen;
+
+                     [assembly: VogenDefaults(customizations: Customizations.AddFactoryMethodForGuids)]
+
+                       [ValueObject<Guid>]
+                       public partial {{type}} MyVo { }
+
+                     """;
+
+            await new SnapshotRunner<ValueObjectGenerator>()
+                .WithSource(source)
+                .CustomizeSettings(s => s.UseFileName(TestHelper.ShortenForFilename(type)))
+                .RunOnAllFrameworks();
+    }
+
     [Fact]
     public async Task ServiceStackDotTextConversion_generates_static_constructor_for_strings()
     {
@@ -21,7 +46,6 @@ public partial struct MyVo { }
         static Task RunTest(string source) =>
             new SnapshotRunner<ValueObjectGenerator>()
                 .WithSource(source)
-                //.WithPackage(new NuGetPackage("ServiceStack.Text", "8.2.2", "lib/net8.0" ))
                 .RunOn(TargetFramework.Net8_0);
     }
 
@@ -56,7 +80,6 @@ public partial struct MyVo { }
         static Task RunTest(string source) =>
             new SnapshotRunner<ValueObjectGenerator>()
                 .WithSource(source)
-                // .WithPackage(new NuGetPackage("ServiceStack.Text", "8.2.2", "lib/net8.0" ))
                 .RunOn(TargetFramework.Net8_0);
     }
 
@@ -74,7 +97,6 @@ public partial struct MyVo { }
         static Task RunTest(string source) =>
             new SnapshotRunner<ValueObjectGenerator>()
                 .WithSource(source)
-                // .WithPackage(new NuGetPackage("ServiceStack.Text", "8.2.2", "lib/net8.0" ))
                 .RunOn(TargetFramework.Net8_0);
     }