changed Error serialization

Railway/Error.cs

@@ -1,14 +1,10 @@
 using System.Collections;
 using System.Collections.Immutable;
-using System.Runtime.Serialization;
 using System.Text;
 
 namespace Just.Railway;
 
-[JsonPolymorphic(TypeDiscriminatorPropertyName = "$$err")]
-[JsonDerivedType(typeof(ExpectedError), typeDiscriminator: 0)]
-[JsonDerivedType(typeof(ExceptionalError), typeDiscriminator: 1)]
-[JsonDerivedType(typeof(ManyErrors))]
+[JsonConverter(typeof(ErrorJsonConverter))]
 public abstract class Error : IEquatable<Error>, IComparable<Error>
 {
     protected internal Error(){}
@@ -33,16 +29,22 @@ public abstract class Error : IEquatable<Error>, IComparable<Error>
     /// </summary>
     /// <param name="message">Error detail</param>
     [Pure, MethodImpl(MethodImplOptions.AggressiveInlining)]
-    public static Error New(string message) =>
-        new ExpectedError("error", message);
+    public static Error New(string message, IEnumerable<KeyValuePair<string, string>>? extensionData = null) =>
+        new ExpectedError("error", message)
+        {
+            ExtensionData = extensionData?.ToImmutableDictionary() ?? ImmutableDictionary<string, string>.Empty
+        };
     /// <summary>
     /// Create an <see cref="ExpectedError"/>
     /// </summary>
     /// <param name="type">Error code</param>
     /// <param name="message">Error detail</param>
     [Pure, MethodImpl(MethodImplOptions.AggressiveInlining)]
-    public static Error New(string type, string message) =>
-        new ExpectedError(type, message);
+    public static Error New(string type, string message, IEnumerable<KeyValuePair<string, string>>? extensionData = null) =>
+        new ExpectedError(type, message)
+        {
+            ExtensionData = extensionData?.ToImmutableDictionary() ?? ImmutableDictionary<string, string>.Empty
+        };
     /// <summary>
     /// Create a <see cref="ManyErrors"/>
     /// </summary>
@@ -50,7 +52,7 @@ public abstract class Error : IEquatable<Error>, IComparable<Error>
     [Pure, MethodImpl(MethodImplOptions.AggressiveInlining)]
     public static Error Many(Error error1, Error error2) => (error1, error2) switch
     {
-        (null, null) => new ManyErrors(Enumerable.Empty<Error>()),
+        (null, null) => new ManyErrors([]),
         (Error err, null) => err,
         (Error err, { IsEmpty: true }) => err,
         (null, Error err) => err,
@@ -76,13 +78,14 @@ public abstract class Error : IEquatable<Error>, IComparable<Error>
 
     [Pure] public abstract string Type { get; }
     [Pure] public abstract string Message { get; }
-    [Pure, JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingNull)] public ImmutableDictionary<string, string>? ExtensionData { get; init; }
-    [Pure] public string? this[string key] => ExtensionData?.TryGetValue(key, out var value) == true ? value : null;
 
-    [Pure, JsonIgnore] public abstract int Count { get; }
-    [Pure, JsonIgnore] public abstract bool IsEmpty { get; }
-    [Pure, JsonIgnore] public abstract bool IsExpected { get; }
-    [Pure, JsonIgnore] public abstract bool IsExeptional { get; }
+    [Pure] public ImmutableDictionary<string, string> ExtensionData { get; internal init; } = ImmutableDictionary<string, string>.Empty;
+    [Pure] public string? this[string key] => ExtensionData.TryGetValue(key, out var value) == true ? value : null;
+
+    [Pure] public abstract int Count { get; }
+    [Pure] public abstract bool IsEmpty { get; }
+    [Pure] public abstract bool IsExpected { get; }
+    [Pure] public abstract bool IsExeptional { get; }
 
     [Pure] public Error Append(Error? next)
     {
@@ -142,9 +145,9 @@ public abstract class Error : IEquatable<Error>, IComparable<Error>
     }
 }
 
+[JsonConverter(typeof(ExpectedErrorJsonConverter))]
 public sealed class ExpectedError : Error
 {
-    [JsonConstructor]
     public ExpectedError(string type, string message)
     {
         Type = type;
@@ -158,10 +161,10 @@ public sealed class ExpectedError : Error
     [Pure] public override string Type { get; }
     [Pure] public override string Message { get; }
 
-    [Pure, JsonIgnore] public override int Count => 1;
-    [Pure, JsonIgnore] public override bool IsEmpty => false;
-    [Pure, JsonIgnore] public override bool IsExpected => true;
-    [Pure, JsonIgnore] public override bool IsExeptional => false;
+    [Pure] public override int Count => 1;
+    [Pure] public override bool IsEmpty => false;
+    [Pure] public override bool IsExpected => true;
+    [Pure] public override bool IsExeptional => false;
 
     [Pure, MethodImpl(MethodImplOptions.AggressiveInlining)]
     public override IEnumerable<Error> ToEnumerable()
@@ -170,24 +173,24 @@ public sealed class ExpectedError : Error
     }
 }
 
+[JsonConverter(typeof(ExceptionalErrorJsonConverter))]
 public sealed class ExceptionalError : Error
 {
     internal readonly Exception? Exception;
 
     internal ExceptionalError(Exception exception)
-        : this(exception.GetType().Name, exception.Message)
+        : this(exception.GetType().FullName ?? exception.GetType().Name, exception.Message)
     {
         Exception = exception;
         ExtensionData = ExtractExtensionData(exception);
     }
     internal ExceptionalError(string message, Exception exception)
-        : this(exception.GetType().Name, message)
+        : this(exception.GetType().FullName ?? exception.GetType().Name, message)
     {
         Exception = exception;
         ExtensionData = ExtractExtensionData(exception);
     }
 
-    [JsonConstructor]
     public ExceptionalError(string type, string message)
     {
         Type = type;
@@ -197,10 +200,10 @@ public sealed class ExceptionalError : Error
     [Pure] public override string Type { get; }
     [Pure] public override string Message { get; }
 
-    [Pure, JsonIgnore] public override int Count => 1;
-    [Pure, JsonIgnore] public override bool IsEmpty => false;
-    [Pure, JsonIgnore] public override bool IsExpected => false;
-    [Pure, JsonIgnore] public override bool IsExeptional => true;
+    [Pure] public override int Count => 1;
+    [Pure] public override bool IsEmpty => false;
+    [Pure] public override bool IsExpected => false;
+    [Pure] public override bool IsExeptional => true;
 
     [Pure] public override Exception ToException() => Exception ?? base.ToException();
 
@@ -210,10 +213,10 @@ public sealed class ExceptionalError : Error
         yield return this;
     }
 
-    private static ImmutableDictionary<string, string>? ExtractExtensionData(Exception exception)
+    private static ImmutableDictionary<string, string> ExtractExtensionData(Exception exception)
     {
         if (!(exception.Data?.Count > 0))
-        return null;
+        return ImmutableDictionary<string, string>.Empty;
 
         List<KeyValuePair<string, string>>? values = null;
 
@@ -231,16 +234,17 @@ public sealed class ExceptionalError : Error
             values ??= [];
             values.Add(new(keyString, valueString));
         }
-        return values?.ToImmutableDictionary();
+        return values?.ToImmutableDictionary() ?? ImmutableDictionary<string, string>.Empty;
     }
 }
 
-[DataContract]
-public sealed class ManyErrors : Error, IEnumerable<Error>
+[JsonConverter(typeof(ManyErrorsJsonConverter))]
+public sealed class ManyErrors : Error, IEnumerable<Error>, IReadOnlyList<Error>
 {
     private readonly List<Error> _errors;
-    [Pure, DataMember] public IEnumerable<Error> Errors { get => _errors; }
+    [Pure] public IEnumerable<Error> Errors { get => _errors; }
 
+    internal ManyErrors(List<Error> errors) => _errors = errors;
     internal ManyErrors(Error head, Error tail)
     {
         _errors = new List<Error>(head.Count + tail.Count);
@@ -283,9 +287,11 @@ public sealed class ManyErrors : Error, IEnumerable<Error>
     }
 
     [Pure] public override int Count => _errors.Count;
-    [Pure, JsonIgnore] public override bool IsEmpty => _errors.Count == 0;
-    [Pure, JsonIgnore] public override bool IsExpected => _errors.All(static x => x.IsExpected);
-    [Pure, JsonIgnore] public override bool IsExeptional => _errors.Any(static x => x.IsExeptional);
+    [Pure] public override bool IsEmpty => _errors.Count == 0;
+    [Pure] public override bool IsExpected => _errors.All(static x => x.IsExpected);
+    [Pure] public override bool IsExeptional => _errors.Any(static x => x.IsExeptional);
+
+    [Pure] public Error this[int index] => _errors[index];
 
     [Pure] public override Exception ToException() => new AggregateException(_errors.Select(static x => x.ToException()));
     [Pure] public override IEnumerable<Error> ToEnumerable() => _errors;

Railway/ErrorJsonConverter.cs

@@ -0,0 +1,182 @@
+using System.Collections.Immutable;
+
+namespace Just.Railway;
+
+public sealed class ErrorJsonConverter : JsonConverter<Error>
+{
+    public override Error? Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options)
+    {
+        return reader.TokenType switch
+        {
+            JsonTokenType.StartObject => ToExpectedError(ReadOne(ref reader)),
+            JsonTokenType.StartArray => ReadMany(ref reader),
+            JsonTokenType.None => null,
+            JsonTokenType.Null => null,
+            _ => throw new JsonException("Unexpected JSON token.")
+        };
+    }
+
+    public override void Write(Utf8JsonWriter writer, Error value, JsonSerializerOptions options)
+    {
+        if (value is ManyErrors manyErrors)
+        {
+            writer.WriteStartArray();
+            foreach (var err in manyErrors)
+            {
+                WriteOne(writer, err);
+            }
+            writer.WriteEndArray();
+        }
+        else
+        {
+            WriteOne(writer, value);
+        }
+    }
+
+    internal static ManyErrors ReadMany(ref Utf8JsonReader reader)
+    {
+        List<Error> errors = [];
+        while (reader.Read())
+        {
+            if (reader.TokenType == JsonTokenType.StartObject)
+            {
+                errors.Add(ToExpectedError(ReadOne(ref reader)));
+            }
+        }
+        return new ManyErrors(errors);
+    }
+    internal static ExpectedError ToExpectedError(in (string Type, string Message, ImmutableDictionary<string, string> ExtensionData) errorInfo)
+        => new(errorInfo.Type, errorInfo.Message) { ExtensionData = errorInfo.ExtensionData };
+    internal static (string Type, string Message, ImmutableDictionary<string, string> ExtensionData) ReadOne(ref Utf8JsonReader reader)
+    {
+        List<KeyValuePair<string, string>>? extensionData = null;
+        string type = "error";
+        string message = "";
+        while (reader.Read())
+        {
+            switch (reader.TokenType)
+            {
+                case JsonTokenType.PropertyName:
+                {
+                    var propname = reader.GetString();
+                    reader.Read();
+
+                    if (reader.TokenType == JsonTokenType.Null)
+                        break;
+
+                    while (reader.TokenType == JsonTokenType.Comment) reader.Read();
+
+                    if (!(reader.TokenType == JsonTokenType.String))
+                        throw new JsonException("Unable to deserialize Error type.");
+                    
+                    var propvalue = reader.GetString();
+                    if (string.IsNullOrEmpty(propvalue))
+                        break;
+
+                    if (propname == "type" || string.Equals(propname, "type", StringComparison.InvariantCultureIgnoreCase))
+                    {
+                        type = propvalue;
+                    }
+                    else if (propname == "msg" || string.Equals(propname, "msg", StringComparison.InvariantCultureIgnoreCase))
+                    {
+                        message = propvalue;
+                    }
+                    else if (!string.IsNullOrEmpty(propname))
+                    {
+                        extensionData ??= [];
+                        extensionData.Add(new(propname, propvalue));
+                    }
+
+                    break;
+                }
+                case JsonTokenType.Comment: break;
+                case JsonTokenType.EndObject: goto endLoop;
+                default: throw new JsonException("Unable to deserialize Error type.");
+            }
+        }
+        endLoop:
+        return (type, message, extensionData?.ToImmutableDictionary() ?? ImmutableDictionary<string, string>.Empty);
+    }
+    internal static void WriteOne(Utf8JsonWriter writer, Error value)
+    {
+        writer.WriteStartObject();
+
+        writer.WriteString("type", value.Type);
+        writer.WriteString("msg", value.Message);
+
+        if (value.ExtensionData?.Count > 0)
+        {
+            foreach (var (key, val) in value.ExtensionData)
+            {
+                writer.WriteString(key, val);
+            }
+        }
+
+        writer.WriteEndObject();
+    }
+}
+
+public sealed class ExpectedErrorJsonConverter : JsonConverter<ExpectedError>
+{
+    public override ExpectedError? Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options)
+    {
+        return reader.TokenType switch
+        {
+            JsonTokenType.StartObject => ErrorJsonConverter.ToExpectedError(ErrorJsonConverter.ReadOne(ref reader)),
+            JsonTokenType.None => null,
+            JsonTokenType.Null => null,
+            _ => throw new JsonException("Unexpected JSON token.")
+        };
+    }
+
+    public override void Write(Utf8JsonWriter writer, ExpectedError value, JsonSerializerOptions options)
+    {
+        ErrorJsonConverter.WriteOne(writer, value);
+    }
+}
+
+public sealed class ExceptionalErrorJsonConverter : JsonConverter<ExceptionalError>
+{
+    public override ExceptionalError? Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options)
+    {
+        return reader.TokenType switch
+        {
+            JsonTokenType.StartObject => ToExceptionalError(ErrorJsonConverter.ReadOne(ref reader)),
+            JsonTokenType.None => null,
+            JsonTokenType.Null => null,
+            _ => throw new JsonException("Unexpected JSON token.")
+        };
+    }
+
+    public override void Write(Utf8JsonWriter writer, ExceptionalError value, JsonSerializerOptions options)
+    {
+        ErrorJsonConverter.WriteOne(writer, value);
+    }
+
+    private static ExceptionalError ToExceptionalError(in (string Type, string Message, ImmutableDictionary<string, string> ExtensionData) errorInfo)
+        => new(errorInfo.Type, errorInfo.Message) { ExtensionData = errorInfo.ExtensionData };
+}
+
+public sealed class ManyErrorsJsonConverter : JsonConverter<ManyErrors>
+{
+    public override ManyErrors? Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options)
+    {
+        return reader.TokenType switch
+        {
+            JsonTokenType.StartArray => ErrorJsonConverter.ReadMany(ref reader),
+            JsonTokenType.None => null,
+            JsonTokenType.Null => null,
+            _ => throw new JsonException("Unexpected JSON token.")
+        };
+    }
+
+    public override void Write(Utf8JsonWriter writer, ManyErrors value, JsonSerializerOptions options)
+    {
+        writer.WriteStartArray();
+        foreach (var err in value)
+        {
+            ErrorJsonConverter.WriteOne(writer, err);
+        }
+        writer.WriteEndArray();
+    }
+}

Railway/Railway.csproj

@@ -7,10 +7,11 @@
     <AssemblyName>Just.Railway</AssemblyName>
     <RootNamespace>Just.Railway</RootNamespace>
     
+    <Description>Base for railway-oriented programming in .NET. Package includes Result object, Error class and most of the common extensions.</Description>
+    <PackageTags>railway-oriented;functional;result-pattern;result-object;error-handling</PackageTags>
     <Authors>JustFixMe</Authors>
     <Copyright>Copyright (c) 2023 JustFixMe</Copyright>
     <PackageLicenseExpression>MIT</PackageLicenseExpression>
-    <RepositoryUrl>https://gitea.jstdev.ru/just/Just.Railway/</RepositoryUrl>
     
     <EmitCompilerGeneratedFiles Condition="'$(Configuration)'=='Debug'">true</EmitCompilerGeneratedFiles>
     <ReleaseVersion Condition=" '$(ReleaseVersion)' == '' ">1.0.0</ReleaseVersion>