Enhance JSON Serialization and Deserialization

Updated serialization for `Money` type to support advanced formats, including reversed currency/amount strings. Improved error handling with concise messages for invalid formats. Expanded test coverage for varied JSON serialization scenarios, ensuring robustness with both valid and invalid test cases.

src/NodaMoney/ExchangeRate.cs

@@ -169,7 +169,7 @@ public override int GetHashCode()
             {
                 return Value.GetHashCode() + (397 * BaseCurrency.GetHashCode()) + (397 * QuoteCurrency.GetHashCode());
             }
-        }
+    }
 
     /// <summary>Indicates whether this instance and a specified <see cref="ExchangeRate"/> are equal.</summary>
     /// <param name="other">Another object to compare to.</param>

src/NodaMoney/Money.Serializable.cs

@@ -11,8 +11,9 @@ namespace NodaMoney;
 
 /// <summary>Represents Money, an amount defined in a specific Currency.</summary>
 [Serializable]
-//[TypeConverter(typeof(MoneyTypeConverter))]
-[JsonConverter(typeof(MoneyJsonConverter))]
+[TypeConverter(typeof(MoneyTypeConverter))] // Used by Newtonsoft.Json JSON String to do the serialization.
+[JsonConverter(typeof(MoneyJsonConverter))] // Used by System.Text.Json to do the serialization.
+//[JsonConverter(typeof(NullableMoneyJsonConverter))]
 // IXmlSerializable used for XML serialization (ReadXml, WriteXml, GetSchema),
 // ISerializable for binary serialization (GetObjectData, ctor(SerializationInfo, StreamingContext))
 public partial struct Money : IXmlSerializable, ISerializable

src/NodaMoney/MoneyJsonConverter.cs

@@ -7,20 +7,26 @@ namespace NodaMoney;
 /// <inheritdoc />
 public class MoneyJsonConverter : JsonConverter<Money>
 {
+    //public override bool HandleNull => false;
+
     /// <inheritdoc />
     public override Money Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options)
     {
         if (reader.TokenType == JsonTokenType.Null)
         {
-            //return (Money)null;
+            throw new JsonException("Unexpected null value for Money.");
+            return default;
+            //return null;
         }
 
-        // new serialization format (v2): "EUR 234.25"
+        // new serialization format (v2): "EUR 234.25" (or "234.25 EUR")
+        // TODO: serialize non-ISO-4217 currencies with same code as ISO-4217 currencies, like "XXX;NON-ISO 234.25" or something else
         if (reader.TokenType == JsonTokenType.String)
         {
-            string value = reader.GetString();
+            string? value = reader.GetString();
             if (string.IsNullOrWhiteSpace(value))
             {
+                throw new JsonException("Invalid format for Money. Expected format is 'Currency Amount', like 'EUR 234.25'.");
                 //return (Money)null;
             }
             else
@@ -29,16 +35,35 @@ public override Money Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSe
                 int spaceIndex = valueAsSpan.IndexOf(' ');
                 if (spaceIndex == -1)
                 {
-                    throw new JsonException("Invalid format for Money. Expected format is 'Currency Amount'.");
+                    throw new JsonException("Invalid format for Money. Expected format is 'Currency Amount', like 'EUR 234.25'.");
                 }
 
                 ReadOnlySpan<char> currencySpan = valueAsSpan.Slice(0, spaceIndex);
                 ReadOnlySpan<char> amountSpan = valueAsSpan.Slice(spaceIndex + 1);
 
-                Currency currency1 = new Currency(currencySpan.ToString());
-                decimal amount1 = decimal.Parse(amountSpan.ToString(), NumberStyles.Any, CultureInfo.InvariantCulture);
+                try
+                {
+                    Currency currency1 = new Currency(currencySpan.ToString());
+                    decimal amount1 = decimal.Parse(amountSpan.ToString(), NumberStyles.Any, CultureInfo.InvariantCulture);
+
+                    return new Money(amount1, currency1);
+                }
+                catch (Exception ex) when (ex is FormatException or ArgumentException)
+                {
+                    try
+                    {
+                        // try reverse 234.25 EUR
+                        Currency currency1 = new Currency(amountSpan.ToString());
+                        decimal amount1 = decimal.Parse(currencySpan.ToString(), NumberStyles.Any, CultureInfo.InvariantCulture);
 
-                return new Money(amount1, currency1);
+                        return new Money(amount1, currency1);
+                    }
+                    catch (Exception reverseException)  when (reverseException is FormatException or ArgumentException)
+                    {
+                        // throw with original exception!
+                        throw new JsonException("Invalid format for Money. Expected format is 'Currency Amount', like 'EUR 234.25'.", ex);
+                    }
+                }
             }
         }
 
@@ -109,14 +134,12 @@ public override Money Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSe
     /// <inheritdoc />
     public override void Write(Utf8JsonWriter writer, Money money, JsonSerializerOptions options)
     {
+        if (money == null)
+        {
+            writer.WriteNullValue();
+            return;
+        }
+
         writer.WriteStringValue($"{money.Currency.Code.ToString(CultureInfo.InvariantCulture)} {money.Amount.ToString(CultureInfo.InvariantCulture)}");
-        // if (money == null)
-        // {
-        //     writer.WriteNullValue();
-        // }
-        // else
-        // {
-        //     writer.WriteStringValue($"{money.Currency.Code.ToString(CultureInfo.InvariantCulture)} {money.Amount.ToString(CultureInfo.InvariantCulture)}");
-        // }
     }
 }

src/NodaMoney/MoneyTypeConverter.cs

@@ -1,46 +1,68 @@
 using System.ComponentModel;
 using System.Globalization;
+using System.Runtime.Serialization;
 using System.Text;
 
 namespace NodaMoney;
 
 /// <summary>Provides a way of converting the type <see cref="string"/> to and from the type <see cref="Money"/>.</summary>
-/// <remarks>Used by <see cref="Newtonsoft.Json."/> to do the serialization.</remarks>
+/// <remarks>Used by <see cref="Newtonsoft.Json"/> for JSON Strings to do the serialization.</remarks>
 public class MoneyTypeConverter : TypeConverter
 {
     /// <inheritdoc/>
     public override bool CanConvertFrom(ITypeDescriptorContext? context, Type sourceType) =>
-        sourceType == typeof(string) || base.CanConvertFrom(context, sourceType);
+        sourceType == typeof(string) || sourceType == typeof(Money) || base.CanConvertFrom(context, sourceType);
 
     /// <inheritdoc/>
     public override bool CanConvertTo(ITypeDescriptorContext? context, Type? destinationType) =>
-        destinationType == typeof(Money) || base.CanConvertTo(context, destinationType);
+        destinationType == typeof(Money) || destinationType == typeof(string) || base.CanConvertTo(context, destinationType);
 
     /// <inheritdoc/>
     public override object ConvertFrom(ITypeDescriptorContext context, CultureInfo culture, object? value)
     {
-        if (value is string valueAsString)
+        // Newtonsoft.Json will call this method when it is a JSON String, like "EUR 234.25",
+        // but if it is a JSON Object it tries to check if it can convert JObject (in Newtonsoft.Json).
+
+        if (value is not string jsonString)
+            return base.ConvertFrom(context, culture, value);
+
+        var valueAsSpan = jsonString.AsSpan();
+        var spaceIndex = valueAsSpan.IndexOf(' ');
+        if (spaceIndex == -1)
         {
-            // Use Span<T> to slice the string without creating a new array
-            var valueAsSpan = valueAsString.AsSpan();
-            var separatorIndex = valueAsSpan.IndexOf(' ');
-            if (separatorIndex == -1)
-            {
-                throw new FormatException("Invalid format. Expected format is 'amount currency' but didn't find a space.");
-            }
+            throw new FormatException("Invalid format for Money. Expected format is 'Currency Amount', like 'EUR 234.25', but didn't find a space.");
+        }
 
-            var amountPart = valueAsSpan.Slice(0, separatorIndex);
-            var currencyPart = valueAsSpan.Slice(separatorIndex + 1);
+        ReadOnlySpan<char> currencySpan = valueAsSpan.Slice(0, spaceIndex);
+        ReadOnlySpan<char> amountSpan = valueAsSpan.Slice(spaceIndex + 1);
 
-            var amount = decimal.Parse(amountPart.ToString(), culture);
-            var currency = new Currency(currencyPart.ToString());
+        try
+        {
+            Currency currency1 = new Currency(currencySpan.ToString());
+            decimal amount1 = decimal.Parse(amountSpan.ToString(), NumberStyles.Any, CultureInfo.InvariantCulture);
 
-            return new Money(amount, currency);
+            return new Money(amount1, currency1);
+        }
+        catch (Exception ex) when (ex is FormatException or ArgumentException)
+        {
+            try
+            {
+                // try reverse: 234.25 EUR
+                Currency currency1 = new Currency(amountSpan.ToString());
+                decimal amount1 = decimal.Parse(currencySpan.ToString(), NumberStyles.Any, CultureInfo.InvariantCulture);
 
-            // string[] v = valueAsString.Split([' ']);
-            // return new Money(decimal.Parse(v[0], culture), v[1]);
+                return new Money(amount1, currency1);
+            }
+            catch (Exception reverseException)  when (reverseException is FormatException or ArgumentException)
+            {
+                // throw with original exception!
+                throw new SerializationException("Invalid format for Money. Expected format is 'Currency Amount', like 'EUR 234.25'.", ex);
+            }
         }
 
+        // old serialization format (v1): { "Amount": 234.25, "Currency": "EUR" }
+        // use the build in converter for this.
+
         return base.ConvertFrom(context, culture, value);
     }
 
@@ -50,9 +72,9 @@ public override object ConvertFrom(ITypeDescriptorContext context, CultureInfo c
         if (destinationType == typeof(string) && value is Money money)
         {
             var result = new StringBuilder();
-            result.Append(money.Amount.ToString(culture));
-            result.Append(' ');
             result.Append(money.Currency.Code.ToString(culture));
+            result.Append(' ');
+            result.Append(money.Amount.ToString(culture));
 
             return result.ToString();
         }

tests/NodaMoney.Tests/Serialization/NewtonsoftJsonSerializer.cs

@@ -59,7 +59,9 @@ public void WhenOrder_ThenThisShouldSucceed(Money money, string expectedCurrency
     {
         // Arrange
         var order = new Order { Id = 123, Name = "Foo", Total = money };
-        string expected = $$"""{"Id":123,"Name":"Foo","Total":"{{expectedMoney}}"}""";
+        string expected = $$"""
+                            {"Id":123,"Total":"{{expectedMoney}}","Name":"Foo"}
+                            """;
 
         // Act
         string json = JsonConvert.SerializeObject(order);
@@ -77,7 +79,7 @@ public void WhenNullableOrder_ThenThisShouldSucceed(Money money, string expected
     {
         // Arrange
         var order = new NullableOrder() { Id = 123, Name = "Foo", Total = money };
-        string expected = $$"""{"Id":123,"Name":"Foo","Price":"{{expectedMoney}}"}""";
+        string expected = $$"""{"Id":123,"Total":"{{expectedMoney}}","Name":"Foo"}""";
 
         // Act
         string json = JsonConvert.SerializeObject(order);
@@ -94,7 +96,7 @@ public class GivenIWantToDeserializeMoney
 {
     [Theory]
     [ClassData(typeof(ValidJsonV1TestData))]
-    public void WhenDeserializing_ThenThisShouldSucceed(string json, Money expected)
+    public void WhenDeserializingV1_ThenThisShouldSucceed(string json, Money expected)
     {
         var clone = JsonConvert.DeserializeObject<Money>(json);
 
@@ -103,16 +105,43 @@ public void WhenDeserializing_ThenThisShouldSucceed(string json, Money expected)
 
     [Theory]
     [ClassData(typeof(InvalidJsonV1TestData))]
-    public void WhenDeserializingWithInvalidJSON_ThenThisShouldFail(string json)
+    public void WhenDeserializingWithInvalidJSONV1_ThenThisShouldFail(string json)
     {
         Action action = () => JsonConvert.DeserializeObject<Money>(json);
 
-        action.Should().Throw<SerializationException>().WithMessage("Member '*");
+        action.Should().Throw<SerializationException>();
     }
 
     [Theory]
     [ClassData(typeof(NestedJsonV1TestData))]
-    public void WhenDeserializingWithNested_ThenThisShouldSucceed(string json, Order expected)
+    public void WhenDeserializingWithNestedV1_ThenThisShouldSucceed(string json, Order expected)
+    {
+        var clone = JsonConvert.DeserializeObject<Order>(json);
+
+        clone.Should().BeEquivalentTo(expected);
+    }
+
+    [Theory]
+    [ClassData(typeof(ValidJsonV2TestData))]
+    public void WhenDeserializingV2_ThenThisShouldSucceed(string json, Money expected)
+    {
+        var clone = JsonConvert.DeserializeObject<Money>(json);
+
+        clone.Should().Be(expected);
+    }
+
+    [Theory]
+    [ClassData(typeof(InvalidJsonV2TestData))]
+    public void WhenDeserializingWithInvalidJSONV2_ThenThisShouldFail(string json)
+    {
+        Action action = () => JsonConvert.DeserializeObject<Money>(json);
+
+        action.Should().Throw<JsonException>();
+    }
+
+    [Theory]
+    [ClassData(typeof(NestedJsonV2TestData))]
+    public void WhenDeserializingWithNestedV2_ThenThisShouldSucceed(string json, Order expected)
     {
         var clone = JsonConvert.DeserializeObject<Order>(json);
 

tests/NodaMoney.Tests/Serialization/RavenDbSerializationSpec.cs

@@ -7,30 +7,13 @@ namespace NodaMoney.Tests.Serialization.RavenDbSerializationSpec;
 
 public class GivenIWantToStoreInRavenDb : RavenTestDriver
 {
-    [Fact]
-    public void WhenMoneyAsRoot_ThenThisMustWork()
+    static GivenIWantToStoreInRavenDb()
     {
-        Money euros = new Money(123.56, "EUR");
-
-        using var store = GetDocumentStore();
-
-        // Store in RavenDb
-        using (var session = store.OpenSession())
+        // ConfigureServer() must be set before calling GetDocumentStore() and can only be set once per test run.
+        ConfigureServer(new TestServerOptions
         {
-            session.Store(euros);
-            session.SaveChanges();
-        }
-
-        WaitForIndexing(store);
-        //WaitForUserToContinueTheTest(store); // Sometimes we want to debug the test itself, this redirect us to the studio
-
-        // Read from RavenDb
-        using (var session = store.OpenSession())
-        {
-            var result = session.Query<Money>().FirstOrDefault();
-
-            result.Should().Be(euros);
-        }
+            Licensing = { ThrowOnInvalidOrMissingLicense = false }
+        });
     }
 
     [Fact]
@@ -48,7 +31,7 @@ public void WhenObjectWithMoneyAttribute_ThenThisMustWork()
             }
 
             WaitForIndexing(store);
-            WaitForUserToContinueTheTest(store); // Sometimes we want to debug the test itself, this redirect us to the studio
+            //WaitForUserToContinueTheTest(store); // Sometimes we want to debug the test itself, this redirect us to the studio
 
             // Read from RavenDb
             using (var session = store.OpenSession())