System.Text.Json: String-Based keyed value objects (and smart enums) …

…can be used as dictionary keys
PawelGerr · Jan 31, 2024 · dcd4e25 · dcd4e25
1 parent 6245b4e
commit dcd4e25
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Showing 10 changed files with 151 additions and 13 deletions.
diff --git a/Directory.Build.props b/Directory.Build.props
@@ -2,7 +2,7 @@
 
    <PropertyGroup>
       <Copyright>(c) $([System.DateTime]::Now.Year), Pawel Gerr. All rights reserved.</Copyright>
-      <VersionPrefix>7.1.0</VersionPrefix>
+      <VersionPrefix>7.2.0</VersionPrefix>
       <Authors>Pawel Gerr</Authors>
       <GenerateDocumentationFile>true</GenerateDocumentationFile>
       <PackageProjectUrl>https://github.com/PawelGerr/Thinktecture.Runtime.Extensions</PackageProjectUrl>

diff --git a/src/Thinktecture.Runtime.Extensions.Json/Text/Json/Serialization/ValueObjectJsonConverter.cs b/src/Thinktecture.Runtime.Extensions.Json/Text/Json/Serialization/ValueObjectJsonConverter.cs
@@ -54,3 +54,64 @@ public override void Write(Utf8JsonWriter writer, T value, JsonSerializerOptions
       _keyConverter.Write(writer, value.ToValue(), options);
    }
 }
+
+/// <summary>
+/// JSON converter for string-based Value Objects.
+/// </summary>
+/// <typeparam name="T">Type of the value object.</typeparam>
+/// <typeparam name="TValidationError">Type of the validation error.</typeparam>
+public sealed class ValueObjectJsonConverter<T, TValidationError> : JsonConverter<T>
+   where T : IValueObjectFactory<T, string, TValidationError>, IValueObjectConvertable<string>
+   where TValidationError : class, IValidationError<TValidationError>
+{
+   private static readonly bool _mayReturnInvalidObjects = typeof(IValidatableEnum).IsAssignableFrom(typeof(T));
+
+   /// <summary>
+   /// Initializes a new instance of <see cref="ValueObjectJsonConverter{T,TKey,TValidationError}"/>.
+   /// </summary>
+   /// <param name="options">JSON serializer options.</param>
+   public ValueObjectJsonConverter(JsonSerializerOptions options)
+   {
+      ArgumentNullException.ThrowIfNull(options);
+   }
+
+   /// <inheritdoc />
+   public override T? Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options)
+   {
+      var key = reader.GetString();
+
+      if (key is null)
+         return default;
+
+      var validationError = T.Validate(key, null, out var obj);
+
+      if (validationError is not null && !_mayReturnInvalidObjects)
+         throw new JsonException(validationError.ToString() ?? "JSON deserialization failed.");
+
+      return obj;
+   }
+
+   /// <inheritdoc />
+   public override void Write(Utf8JsonWriter writer, T value, JsonSerializerOptions options)
+   {
+      if (value is null)
+         throw new ArgumentNullException(nameof(value));
+
+      writer.WriteStringValue(value.ToValue());
+   }
+
+   /// <inheritdoc />
+   public override T ReadAsPropertyName(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options)
+   {
+      return Read(ref reader, typeToConvert, options) ?? base.ReadAsPropertyName(ref reader, typeToConvert, options);
+   }
+
+   /// <inheritdoc />
+   public override void WriteAsPropertyName(Utf8JsonWriter writer, T value, JsonSerializerOptions options)
+   {
+      if (value is null)
+         throw new ArgumentNullException(nameof(value));
+
+      writer.WritePropertyName(value.ToValue());
+   }
+}
diff --git a/...ecture.Runtime.Extensions.Json/Text/Json/Serialization/ValueObjectJsonConverterFactory.cs b/...ecture.Runtime.Extensions.Json/Text/Json/Serialization/ValueObjectJsonConverterFactory.cs
@@ -29,6 +29,29 @@ public override JsonConverter CreateConverter(Type typeToConvert, JsonSerializer
    }
 }
 
+/// <summary>
+/// Factory for creation of <see cref="ValueObjectJsonConverter{T,TKey,TValidationError}"/>.
+/// </summary>
+public sealed class ValueObjectJsonConverterFactory<T, TValidationError> : JsonConverterFactory
+   where T : IValueObjectFactory<T, string, TValidationError>, IValueObjectConvertable<string>
+   where TValidationError : class, IValidationError<TValidationError>
+{
+   /// <inheritdoc />
+   public override bool CanConvert(Type typeToConvert)
+   {
+      return typeof(T).IsAssignableFrom(typeToConvert);
+   }
+
+   /// <inheritdoc />
+   public override JsonConverter CreateConverter(Type typeToConvert, JsonSerializerOptions options)
+   {
+      ArgumentNullException.ThrowIfNull(typeToConvert);
+      ArgumentNullException.ThrowIfNull(options);
+
+      return new ValueObjectJsonConverter<T, TValidationError>(options);
+   }
+}
+
 /// <summary>
 /// Factory for creation of <see cref="ValueObjectJsonConverter{T,TKey,TValidationError}"/>.
 /// </summary>
@@ -71,7 +94,9 @@ public override JsonConverter CreateConverter(Type typeToConvert, JsonSerializer
 
       var validationErrorType = type.GetCustomAttribute<ValueObjectValidationErrorAttribute>()?.Type ?? typeof(ValidationError);
 
-      var converterType = typeof(ValueObjectJsonConverter<,,>).MakeGenericType(type, keyType, validationErrorType);
+      var converterType = keyType == typeof(string)
+                             ? typeof(ValueObjectJsonConverter<,>).MakeGenericType(type, validationErrorType)
+                             : typeof(ValueObjectJsonConverter<,,>).MakeGenericType(type, keyType, validationErrorType);
       var converter = Activator.CreateInstance(converterType, options);
 
       return (JsonConverter)(converter ?? throw new Exception($"Could not create converter of type '{converterType.Name}'."));

diff --git a/src/Thinktecture.Runtime.Extensions.SourceGenerator/CodeAnalysis/KeyedJsonCodeGenerator.cs b/src/Thinktecture.Runtime.Extensions.SourceGenerator/CodeAnalysis/KeyedJsonCodeGenerator.cs
@@ -22,6 +22,9 @@ public override void Generate(CancellationToken cancellationToken)
                                 .DesiredFactories
                                 .FirstOrDefault(f => f.UseForSerialization.Has(SerializationFrameworks.SystemTextJson));
       var keyType = customFactory?.TypeFullyQualified ?? _state.KeyMember?.TypeFullyQualified;
+      var isString = customFactory is null
+                        ? _state.KeyMember?.SpecialType == SpecialType.System_String
+                        : customFactory.SpecialType == SpecialType.System_String;
 
       _sb.Append(GENERATED_CODE_PREFIX).Append(@"
 ");
@@ -34,7 +37,12 @@ namespace ").Append(_state.Type.Namespace).Append(@";
       }
 
       _sb.Append(@"
-[global::System.Text.Json.Serialization.JsonConverterAttribute(typeof(global::Thinktecture.Text.Json.Serialization.ValueObjectJsonConverterFactory<").Append(_state.Type.TypeFullyQualified).Append(", ").Append(keyType).Append(", ").Append(_state.AttributeInfo.ValidationError.TypeFullyQualified).Append(@">))]
+[global::System.Text.Json.Serialization.JsonConverterAttribute(typeof(global::Thinktecture.Text.Json.Serialization.ValueObjectJsonConverterFactory<").Append(_state.Type.TypeFullyQualified).Append(", ");
+
+      if (!isString)
+         _sb.Append(keyType).Append(", ");
+
+      _sb.Append(_state.AttributeInfo.ValidationError.TypeFullyQualified).Append(@">))]
 partial ").Append(_state.Type.IsReferenceType ? "class" : "struct").Append(" ").Append(_state.Type.Name).Append(@"
 {
 }

diff --git a/...ktecture.Runtime.Extensions.SourceGenerator/CodeAnalysis/KeyedSerializerGeneratorState.cs b/...ktecture.Runtime.Extensions.SourceGenerator/CodeAnalysis/KeyedSerializerGeneratorState.cs
@@ -3,15 +3,15 @@ namespace Thinktecture.CodeAnalysis;
 public readonly struct KeyedSerializerGeneratorState : IEquatable<KeyedSerializerGeneratorState>, INamespaceAndName
 {
    public ITypeInformation Type { get; }
-   public ITypeFullyQualified? KeyMember { get; }
+   public IMemberInformation? KeyMember { get; }
    public AttributeInfo AttributeInfo { get; }
 
    public string? Namespace => Type.Namespace;
    public string Name => Type.Name;
 
    public KeyedSerializerGeneratorState(
       ITypeInformation type,
-      ITypeFullyQualified? keyMember,
+      IMemberInformation? keyMember,
       AttributeInfo attributeInfo)
    {
       Type = type;

diff --git a/...sions.Json.Tests/Text/Json/Serialization/ValueObjectJsonConverterFactoryTests/ReadJson.cs b/...sions.Json.Tests/Text/Json/Serialization/ValueObjectJsonConverterFactoryTests/ReadJson.cs
@@ -196,4 +196,13 @@ public void Should_deserialize_complex_value_object_with_numbers_as_string()
 
       value.Should().BeEquivalentTo(Boundary.Create(1, 2));
    }
+
+   [Fact]
+   public void Should_throw_if_non_string_based_enum_is_used_as_dictionary_key()
+   {
+      var options = new JsonSerializerOptions { Converters = { new ValueObjectJsonConverterFactory() } };
+
+      FluentActions.Invoking(() => JsonSerializer.Deserialize<Dictionary<TestSmartEnum_Class_IntBased, int>>("""{ "1": 1 }""", options))
+                   .Should().Throw<NotSupportedException>();
+   }
 }
diff --git a/...ions.Json.Tests/Text/Json/Serialization/ValueObjectJsonConverterFactoryTests/RoundTrip.cs b/...ions.Json.Tests/Text/Json/Serialization/ValueObjectJsonConverterFactoryTests/RoundTrip.cs
@@ -1,6 +1,10 @@
+using System.Collections.Generic;
 using System.Globalization;
+using System.Text.Json;
 using System.Text.Json.Serialization;
+using Thinktecture.Runtime.Tests.TestEnums;
 using Thinktecture.Runtime.Tests.TestValueObjects;
+using Thinktecture.Text.Json.Serialization;
 
 namespace Thinktecture.Runtime.Tests.Text.Json.Serialization.ValueObjectJsonConverterFactoryTests;
 
@@ -191,4 +195,21 @@ public void Should_deserialize_decimal_from_string_with_corresponding_NumberHand
       Serialize<TestValueObjectDecimal, decimal>(obj, numberHandling: JsonNumberHandling.WriteAsString).Should().Be(numberAsStringJson);
       Deserialize<TestValueObjectDecimal, decimal>($"\"{number}\"", numberHandling: JsonNumberHandling.AllowReadingFromString).Should().Be(obj);
    }
+
+   [Fact]
+   public void Should_roundtrip_serialize_dictionary_with_string_based_enum_key()
+   {
+      var dictionary = new Dictionary<TestSmartEnum_Class_StringBased, int>
+                       {
+                          { TestSmartEnum_Class_StringBased.Value1, 1 },
+                          { TestSmartEnum_Class_StringBased.Value2, 2 }
+                       };
+
+      var options = new JsonSerializerOptions { Converters = { new ValueObjectJsonConverterFactory() } };
+
+      var json = JsonSerializer.Serialize(dictionary, options);
+      var deserializedDictionary = JsonSerializer.Deserialize<Dictionary<TestSmartEnum_Class_StringBased, int>>(json, options);
+
+      dictionary.Should().BeEquivalentTo(deserializedDictionary);
+   }
 }
diff --git a/...ions.Json.Tests/Text/Json/Serialization/ValueObjectJsonConverterFactoryTests/WriteJson.cs b/...ions.Json.Tests/Text/Json/Serialization/ValueObjectJsonConverterFactoryTests/WriteJson.cs
@@ -137,4 +137,18 @@ public void Should_serialize_complex_value_object_with_ValueObjectValidationErro
 
       value.Should().BeEquivalentTo("{\"lower\":1,\"upper\":2}");
    }
+
+   [Fact]
+   public void Should_throw_if_non_string_based_enum_is_used_as_dictionary_key()
+   {
+      var dictionary = new Dictionary<TestSmartEnum_Class_IntBased, int>
+                       {
+                          { TestSmartEnum_Class_IntBased.Value1, 1 }
+                       };
+
+      var options = new JsonSerializerOptions { Converters = { new ValueObjectJsonConverterFactory() } };
+
+      FluentActions.Invoking(() => JsonSerializer.Serialize(dictionary, options))
+                   .Should().Throw<NotSupportedException>();
+   }
 }
diff --git a/...xtensions.SourceGenerator.Tests/SourceGeneratorTests/JsonSmartEnumSourceGeneratorTests.cs b/...xtensions.SourceGenerator.Tests/SourceGeneratorTests/JsonSmartEnumSourceGeneratorTests.cs
@@ -38,7 +38,7 @@ public partial class TestEnum
 
                            namespace Thinktecture.Tests;
 
-                           [global::System.Text.Json.Serialization.JsonConverterAttribute(typeof(global::Thinktecture.Text.Json.Serialization.ValueObjectJsonConverterFactory<global::Thinktecture.Tests.TestEnum, string, global::Thinktecture.ValidationError>))]
+                           [global::System.Text.Json.Serialization.JsonConverterAttribute(typeof(global::Thinktecture.Text.Json.Serialization.ValueObjectJsonConverterFactory<global::Thinktecture.Tests.TestEnum, global::Thinktecture.ValidationError>))]
                            partial class TestEnum
                            {
                            }
@@ -70,7 +70,7 @@ public partial class TestEnum
                            // <auto-generated />
                            #nullable enable
 
-                           [global::System.Text.Json.Serialization.JsonConverterAttribute(typeof(global::Thinktecture.Text.Json.Serialization.ValueObjectJsonConverterFactory<global::TestEnum, string, global::Thinktecture.ValidationError>))]
+                           [global::System.Text.Json.Serialization.JsonConverterAttribute(typeof(global::Thinktecture.Text.Json.Serialization.ValueObjectJsonConverterFactory<global::TestEnum, global::Thinktecture.ValidationError>))]
                            partial class TestEnum
                            {
                            }
@@ -106,7 +106,7 @@ namespace Thinktecture.Tests
 
                            namespace Thinktecture.Tests;
 
-                           [global::System.Text.Json.Serialization.JsonConverterAttribute(typeof(global::Thinktecture.Text.Json.Serialization.ValueObjectJsonConverterFactory<global::Thinktecture.Tests.TestEnum, string, global::Thinktecture.ValidationError>))]
+                           [global::System.Text.Json.Serialization.JsonConverterAttribute(typeof(global::Thinktecture.Text.Json.Serialization.ValueObjectJsonConverterFactory<global::Thinktecture.Tests.TestEnum, global::Thinktecture.ValidationError>))]
                            partial struct TestEnum
                            {
                            }
@@ -130,14 +130,14 @@ public TestEnum_EnumJsonConverter()
                             : this(null)
                          {
                          }
-                   
+
                          public TestEnum_EnumJsonConverter(
                             JsonConverter<string>? keyConverter)
                             : base(TestEnum.Get, keyConverter)
                          {
                          }
                       }
-                   
+
                       [SmartEnum<string>]
                       [JsonConverter(typeof(TestEnumJsonConverter))]
                    	public partial class TestEnum

diff --git a/...ensions.SourceGenerator.Tests/SourceGeneratorTests/JsonValueObjectSourceGeneratorTests.cs b/...ensions.SourceGenerator.Tests/SourceGeneratorTests/JsonValueObjectSourceGeneratorTests.cs
@@ -37,7 +37,7 @@ public partial class TestValueObject
 
                            namespace Thinktecture.Tests;
 
-                           [global::System.Text.Json.Serialization.JsonConverterAttribute(typeof(global::Thinktecture.Text.Json.Serialization.ValueObjectJsonConverterFactory<global::Thinktecture.Tests.TestValueObject, string, global::Thinktecture.ValidationError>))]
+                           [global::System.Text.Json.Serialization.JsonConverterAttribute(typeof(global::Thinktecture.Text.Json.Serialization.ValueObjectJsonConverterFactory<global::Thinktecture.Tests.TestValueObject, global::Thinktecture.ValidationError>))]
                            partial class TestValueObject
                            {
                            }
@@ -67,7 +67,7 @@ public partial class TestValueObject
                            // <auto-generated />
                            #nullable enable
 
-                           [global::System.Text.Json.Serialization.JsonConverterAttribute(typeof(global::Thinktecture.Text.Json.Serialization.ValueObjectJsonConverterFactory<global::TestValueObject, string, global::Thinktecture.ValidationError>))]
+                           [global::System.Text.Json.Serialization.JsonConverterAttribute(typeof(global::Thinktecture.Text.Json.Serialization.ValueObjectJsonConverterFactory<global::TestValueObject, global::Thinktecture.ValidationError>))]
                            partial class TestValueObject
                            {
                            }
@@ -102,7 +102,7 @@ namespace Thinktecture.Tests
 
                            namespace Thinktecture.Tests;
 
-                           [global::System.Text.Json.Serialization.JsonConverterAttribute(typeof(global::Thinktecture.Text.Json.Serialization.ValueObjectJsonConverterFactory<global::Thinktecture.Tests.TestValueObject, string, global::Thinktecture.ValidationError>))]
+                           [global::System.Text.Json.Serialization.JsonConverterAttribute(typeof(global::Thinktecture.Text.Json.Serialization.ValueObjectJsonConverterFactory<global::Thinktecture.Tests.TestValueObject, global::Thinktecture.ValidationError>))]
                            partial struct TestValueObject
                            {
                            }