Extend attribute info.

specs/Qowaiv.CodeGeneration.Specs/OpenApi/JSON_serialization_specs.cs

@@ -0,0 +1,67 @@
+using System.Text.Json;
+using System.Text.Json.Serialization;
+
+namespace Open_API.JSON_serialization_specs;
+
+public class Serializes
+{
+    [Test]
+    public void Model_with_derived_types()
+    {
+        var json = @"{""Items"":[{""Value1"":""1.34534"",""Type"":""Derived1""},{""Value2"":""2.85464"",""Type"":""Derived2""}]}";
+
+        var model = JsonSerializer.Deserialize<MyContainer>(json);
+
+        model.Should().BeEquivalentTo(new MyContainer
+        {
+            Items =
+            [
+                new Derived1{ Type = "Derived1", Value1 = "1.34534" },
+                new Derived2{ Type = "Derived2", Value2 = "2.85464" },
+            ]
+        });
+    }
+}
+
+public class Deserializes
+{
+    [Test]
+    public void Model_with_derived_types()
+    {
+        var model = new MyContainer
+        {
+            Items =
+            [
+                new Derived1{ Type = "Derived1", Value1 = "1.34534" },
+                new Derived2{ Type = "Derived2", Value2 = "2.85464" },
+            ]
+        };
+
+        var json = JsonSerializer.Serialize(model);
+
+
+        Console.WriteLine(json);
+    }
+}
+
+
+internal sealed record MyContainer
+{
+    public MyBase[] Items { get; init; } = [];
+}
+
+[JsonDerivedType(typeof(Derived1))]
+[JsonDerivedType(typeof(Derived2))]
+internal record MyBase
+{
+    public string? Type { get; init; }
+}
+internal sealed record Derived1 : MyBase
+{
+    public string? Value1 { get; init; }
+}
+
+internal sealed record Derived2 : MyBase
+{
+    public string? Value2 { get; init; }
+}

specs/Qowaiv.CodeGeneration.Specs/Syntax/Attribute_decoration_specs.cs

@@ -17,8 +17,7 @@ public void ctor_arguments()
 
     [Test]
     public void parameter_sets()
-        => new AttributeInfo(typeof(TestAttribute),
-            null, KeyValuePair.Create("Author", (object?)"Qowaiv"))
+        => new AttributeInfo(typeof(TestAttribute), null, new { Author = "Qowaiv" })
        .Should().HaveContent("[NUnit.Framework.Test(Author = \"Qowaiv\")]\r\n");
 
     [Test]
@@ -32,11 +31,9 @@ public class Equaly
     [Test]
     public void by_value()
     {
-        var attr = new AttributeInfo(typeof(TestAttribute),
-            null, KeyValuePair.Create("Author", (object?)"Qowaiv"));
+        var attr = new AttributeInfo(typeof(TestAttribute), null, new { Author = "Qowaiv" });
 
-        var ottr = new AttributeInfo(typeof(TestAttribute),
-            null, KeyValuePair.Create("Author", (object?)"Qowaiv"));
+        var ottr = new AttributeInfo(typeof(TestAttribute), null, new { Author = "Qowaiv" });
 
         attr.Equals(ottr).Should().BeTrue();
     }

src/Qowaiv.CodeGeneration/Nill.cs

@@ -0,0 +1,6 @@
+namespace Qowaiv.CodeGeneration;
+
+public sealed class Nill
+{
+    public static readonly Nill Value = new();
+}

src/Qowaiv.CodeGeneration/Syntax/AttributeInfo.Constants.cs

@@ -5,6 +5,9 @@ public partial class AttributeInfo
     /// <summary><see cref="Newtonsoft.Json.JsonConstructorAttribute"/>.</summary>
     public static readonly AttributeInfo Newtonsoft_Json_JsonConstructor = new(typeof(Newtonsoft.Json.JsonConstructorAttribute));
 
+    /// <summary><see cref="Qowaiv.Diagnostics.Contracts.InheritableAttribute"/>.</summary>
+    public static readonly AttributeInfo Qowaiv_Diagnostics_Contracts_Inheritable = new(typeof(Qowaiv.Diagnostics.Contracts.InheritableAttribute));
+
     /// <summary><see cref="Qowaiv.Validation.DataAnnotations.AnyAttribute"/>.</summary>
     public static readonly AttributeInfo Qowaiv_Validation_DataAnnotations_Any = new(typeof(Qowaiv.Validation.DataAnnotations.AnyAttribute));
 
@@ -68,10 +71,24 @@ public static AttributeInfo Qowaiv_Validation_DataAnnotations_AllowedValues(para
     public static AttributeInfo Qowaiv_Validation_DataAnnotations_MultipleOf(double factor)
         => new(typeof(Qowaiv.Validation.DataAnnotations.MultipleOfAttribute), [factor]);
 
+    /// <summary><see cref="System.Text.Json.Serialization.JsonPolymorphicAttribute"/>.</summary>
+    [Pure]
+    public static AttributeInfo System_Text_Json_SerializationJsonPolymorphic(
+        string name,
+        System.Text.Json.Serialization.JsonUnknownDerivedTypeHandling? handling = default,
+        bool? ignoreUnrecognized = false) => new(
+            typeof(System.Text.Json.Serialization.JsonPolymorphicAttribute),
+            [name],
+            new
+            {
+                UnknownDerivedTypeHandling = handling,
+                IgnoreUnrecognizedTypeDiscriminators = ignoreUnrecognized,
+            });
+
     /// <inheritdoc cref="System_Text_Json_Serialization_JsonConverter(Type)"/>
     [Pure]
-    public static AttributeInfo System_Text_Json_Serialization_JsonConverter<T>() where T: System.Text.Json.Serialization.JsonConverter
-        => System_Text_Json_Serialization_JsonConverter(typeof(T));
+    public static AttributeInfo System_Text_Json_Serialization_JsonConverter<TConverter>() where TConverter : System.Text.Json.Serialization.JsonConverter
+        => System_Text_Json_Serialization_JsonConverter(typeof(TConverter));
 
     /// <summary><see cref="System.Text.Json.Serialization.JsonConverterAttribute"/>.</summary>
     [Pure]
@@ -80,13 +97,14 @@ public static AttributeInfo System_Text_Json_Serialization_JsonConverter(Type ty
 
     /// <summary><see cref="System.Text.Json.Serialization.JsonDerivedTypeAttribute"/>.</summary>
     [Pure]
-    public static AttributeInfo System_Text_Json_Serialization_JsonDerivedType(Type type)
-        => new(typeof(System.Text.Json.Serialization.JsonDerivedTypeAttribute), [type]);
+    public static AttributeInfo System_Text_Json_Serialization_JsonDerivedType(Type type, string? discriminator = null) => new(
+        typeof(System.Text.Json.Serialization.JsonDerivedTypeAttribute),
+        discriminator is { } ? [type, discriminator] : [type]);
 
     /// <summary><see cref="System.Text.Json.Serialization.JsonDerivedTypeAttribute"/>.</summary>
     [Pure]
     public static AttributeInfo System_Text_Json_Serialization_JsonIgnore(System.Text.Json.Serialization.JsonIgnoreCondition condition)
-        => new(typeof(System.Text.Json.Serialization.JsonIgnoreAttribute), null, Kvp(nameof(System.Text.Json.Serialization.JsonIgnoreAttribute.Condition), condition));
+        => new(typeof(System.Text.Json.Serialization.JsonIgnoreAttribute), null, new { Condition = condition });
 
     /// <summary><see cref="System.Text.Json.Serialization.JsonPropertyNameAttribute"/>.</summary>
     [Pure]
@@ -96,8 +114,5 @@ public static AttributeInfo System_Text_Json_Serialization_JsonPropertyName(stri
     /// <summary><see cref="System.Runtime.Serialization.EnumMemberAttribute"/>.</summary>
     [Pure]
     public static AttributeInfo System_Runtime_Serialization_EnumMember(string? value)
-        => new(typeof(System.Runtime.Serialization.EnumMemberAttribute), null, Kvp("Value", (object?)value));
-
-    [Pure]
-    private static KeyValuePair<string, object?> Kvp(string key, object? value) => new(key, value);
+        => new(typeof(System.Runtime.Serialization.EnumMemberAttribute), null, new { Value = (object?)value ?? Nill.Value });
 }

src/Qowaiv.CodeGeneration/Syntax/AttributeInfo.cs

@@ -4,13 +4,22 @@ namespace Qowaiv.CodeGeneration.Syntax;
 public sealed partial class AttributeInfo : Code, IEquatable<AttributeInfo>
 {
     /// <summary>Initializes a new instance of the <see cref="AttributeInfo"/> class.</summary>
+    [Obsolete("Use new AttributeInfo(Type, object[]?, dynamic) instead.")]
     public AttributeInfo(Type attribute, object[]? ctorArguments = null, params KeyValuePair<string, object?>[] propertyValues)
     {
         AttributeType = Guard.NotNull(attribute);
         CtorArguments = ctorArguments ?? [];
         PropertyValues = propertyValues ?? [];
     }
 
+    /// <summary>Initializes a new instance of the <see cref="AttributeInfo"/> class.</summary>
+    public AttributeInfo(Type attribute, object[]? ctorArguments = null, dynamic? propertyValues = null)
+    {
+        AttributeType = Guard.NotNull(attribute);
+        CtorArguments = ctorArguments ?? [];
+        PropertyValues = propertyValues is null ? [] : FromDynamic(propertyValues);
+    }
+
     /// <summary>The type of the attribute.</summary>
     public Type AttributeType { get; }
 
@@ -120,4 +129,13 @@ public override int GetHashCode()
 
     /// <summary>Returns false if both have the same values.</summary>
     public static bool operator !=(AttributeInfo? l, AttributeInfo? r) => !(l == r);
+
+    /// <summary>Creates a dictionary from a a dynamic object.</summary>
+    [Pure]
+    private static IReadOnlyCollection<KeyValuePair<string, object?>> FromDynamic(object obj)
+        => obj.GetType()
+            .GetProperties()
+            .Select(p => KeyValuePair.Create(p.Name, p.GetValue(obj)))
+            .Where(kvp => kvp.Value is { })
+            .ToDictionary();
 }

src/Qowaiv.CodeGeneration/Syntax/Literal.cs

@@ -15,6 +15,7 @@ public void WriteTo(CSharpWriter writer)
         Guard.NotNull(writer);
         _ = Value switch
         {
+            Nill or
             null /*.........*/ => writer.Write("null"),
             Type type /*....*/ => writer.Write("typeof(").Write(type).Write(')'),
             bool boolean /*.*/ => writer.Write(boolean ? "true" : "false"),