Fixes #8 - Allow CurrencyExchange section to be either a single item or an array, and add element for InstructedAmount

src/RobinTTY.NordigenApiClient.Tests/Serialization/TransactionTests.cs

@@ -10,20 +10,48 @@ namespace RobinTTY.NordigenApiClient.Tests.Serialization;
 internal class TransactionTests
 {
     /// <summary>
-    /// Tests the correct deserialization of transactions.
+    /// Tests the correct deserialization of transactions with a single embedded currency exchange object.
     /// </summary>
     [Test]
-    public void DeserializeTransaction()
+    public void DeserializeTransactionWithSingleCurrencyExchange()
+    {
+        const string json =
+            "{ \"transactionId\": \"AB123456789\", \"entryReference\": \"123456789\", \"bookingDate\": \"2023-03-20\", \"bookingDateTime\": \"2023-03-20T00:00:00+00:00\", \"transactionAmount\": { \"amount\": \"-33.06\", \"currency\": \"GBP\" }, \"currencyExchange\": { \"sourceCurrency\": \"USD\", \"exchangeRate\": \"1.20961887\", \"unitCurrency\": \"USD\", \"targetCurrency\": \"GBP\", \"instructedAmount\": { \"amount\": \"-33.06\", \"currency\": \"GBP\" } }, \"remittanceInformationUnstructured\": \"my reference here\", \"additionalInformation\": \"123456789\", \"proprietaryBankTransactionCode\": \"OTHER_PURCHASE\", \"merchantCategoryCode\": \"5045\", \"internalTransactionId\": \"abcdef\" }";
+
+        var options = new JsonSerializerOptions
+        {
+            Converters = {new CultureSpecificDecimalConverter()}
+        };
+        var transaction = JsonSerializer.Deserialize<Transaction>(json, options);
+
+        Assert.Multiple(() =>
+        {
+            Assert.That(transaction!.CurrencyExchange, Is.Not.Null);
+            Assert.That(transaction.CurrencyExchange!.First().ExchangeRate, Is.EqualTo(1.20961887));
+            Assert.That(transaction.CurrencyExchange!.First().InstructedAmount!.Amount, Is.EqualTo(-33.06));
+            Assert.That(transaction.CurrencyExchange!.First().InstructedAmount!.Currency, Is.EqualTo("GBP"));
+            Assert.That(transaction.CurrencyExchange!.First().SourceCurrency, Is.EqualTo("USD"));
+            Assert.That(transaction.CurrencyExchange!.First().TargetCurrency, Is.EqualTo("GBP"));
+            Assert.That(transaction.CurrencyExchange!.First().UnitCurrency, Is.EqualTo("USD"));
+            Assert.That(transaction.CurrencyExchange!.First().QuotationDate, Is.Null);
+        });
+    }
+
+    /// <summary>
+    /// Tests the correct deserialization of transactions with multiple embedded currency exchange objects.
+    /// </summary>
+    [Test]
+    public void DeserializeTransactionWithMultipleCurrencyExchange()
     {
         const string json =
             "{ \"transactionId\": \"AB123456789\", \"entryReference\": \"123456789\", \"bookingDate\": \"2023-03-20\", \"bookingDateTime\": \"2023-03-20T00:00:00+00:00\", \"transactionAmount\": { \"amount\": \"-33.06\", \"currency\": \"GBP\" }, \"currencyExchange\":[{\"sourceCurrency\":\"USD\",\"exchangeRate\":\"1.20961887\",\"unitCurrency\":\"USD\",\"targetCurrency\":\"GBP\"}], \"remittanceInformationUnstructured\": \"my reference here\", \"additionalInformation\": \"123456789\", \"proprietaryBankTransactionCode\": \"OTHER_PURCHASE\", \"merchantCategoryCode\": \"5045\", \"internalTransactionId\": \"abcdef\" }";
 
-        // We need the culture specific decimal converter here, since it it accepting strings
         var options = new JsonSerializerOptions
         {
-            Converters = {new JsonWebTokenConverter(), new GuidConverter(), new CultureSpecificDecimalConverter()}
+            Converters = { new CultureSpecificDecimalConverter() }
         };
         var transaction = JsonSerializer.Deserialize<Transaction>(json, options);
+
         Assert.Multiple(() =>
         {
             Assert.That(transaction!.CurrencyExchange, Is.Not.Null);

src/RobinTTY.NordigenApiClient/JsonConverters/SingleOrArrayConverter.cs

@@ -0,0 +1,42 @@
+using System.Text.Json;
+using System.Text.Json.Serialization;
+
+namespace RobinTTY.NordigenApiClient.JsonConverters;
+
+internal class SingleOrArrayConverter<TCollection, TItem> : JsonConverter<TCollection>
+    where TCollection : class, ICollection<TItem>, new()
+{
+    public override TCollection? Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options)
+    {
+        switch (reader.TokenType)
+        {
+            case JsonTokenType.Null:
+                return null;
+            case JsonTokenType.StartArray:
+                var list = new TCollection();
+                while (reader.Read())
+                {
+                    if (reader.TokenType == JsonTokenType.EndArray) break;
+                    var listItem = JsonSerializer.Deserialize<TItem>(ref reader, options);
+                    if (listItem != null) list.Add(listItem);
+                }
+                return list;
+            default:
+                var item = JsonSerializer.Deserialize<TItem>(ref reader, options);
+                return item != null ? new TCollection {item} : null;
+        }
+    }
+
+    public override void Write(Utf8JsonWriter writer, TCollection value, JsonSerializerOptions options)
+    {
+        if (value.Count == 1)
+            JsonSerializer.Serialize(writer, value.First(), options);
+        else
+        {
+            writer.WriteStartArray();
+            foreach (var item in value)
+                JsonSerializer.Serialize(writer, item, options);
+            writer.WriteEndArray();
+        }
+    }
+}

src/RobinTTY.NordigenApiClient/Models/Responses/AmountCurrencyPair.cs

@@ -30,4 +30,4 @@ public AmountCurrencyPair(decimal amount, string currency)
         Amount = amount;
         Currency = currency;
     }
-}
+}

src/RobinTTY.NordigenApiClient/Models/Responses/CurrencyExchange.cs

@@ -7,6 +7,12 @@ namespace RobinTTY.NordigenApiClient.Models.Responses;
 /// </summary>
 public class CurrencyExchange
 {
+    /// <summary>
+    /// The instructed amount including details about the currency the amount is denominated in.
+    /// </summary>
+    [JsonPropertyName("instructedAmount")]
+    public AmountCurrencyPair? InstructedAmount { get; }
+
     /// <summary>
     /// Currency from which an amount is to be converted in a currency conversion. ISO 4217 Alpha 3 currency code (e.g.
     /// "USD").
@@ -51,6 +57,9 @@ public class CurrencyExchange
     /// <summary>
     /// Creates a new instance of <see cref="CurrencyExchange" />.
     /// </summary>
+    /// <param name="instructedAmount">
+    /// The currency and amount as instructed by the debtor, if the actual settlement is of a different currency or amount
+    /// </param>
     /// <param name="sourceCurrency">
     /// Currency from which an amount is to be converted in a currency conversion. ISO 4217 Alpha
     /// 3 currency code (e.g. "USD").
@@ -70,9 +79,10 @@ public class CurrencyExchange
     /// </param>
     /// <param name="quotationDate">Date at which an exchange rate is quoted.</param>
     /// <param name="contractIdentification">Unique identification to unambiguously identify the foreign exchange contract.</param>
-    public CurrencyExchange(string sourceCurrency, string targetCurrency, string unitCurrency, decimal exchangeRate,
+    public CurrencyExchange(AmountCurrencyPair? instructedAmount, string sourceCurrency, string targetCurrency, string unitCurrency, decimal exchangeRate,
         DateTime? quotationDate, string? contractIdentification)
     {
+        InstructedAmount = instructedAmount;    
         SourceCurrency = sourceCurrency;
         TargetCurrency = targetCurrency;
         UnitCurrency = unitCurrency;

src/RobinTTY.NordigenApiClient/Models/Responses/Transaction.cs

@@ -1,4 +1,5 @@
-using System.Text.Json.Serialization;
+using RobinTTY.NordigenApiClient.JsonConverters;
+using System.Text.Json.Serialization;
 
 namespace RobinTTY.NordigenApiClient.Models.Responses;
 
@@ -218,7 +219,8 @@ public class Transaction
     /// Array of the report exchange rate.
     /// </summary>
     [JsonPropertyName("currencyExchange")]
-    public IEnumerable<CurrencyExchange>? CurrencyExchange { get; }
+    [JsonConverter(typeof(SingleOrArrayConverter<List<CurrencyExchange>, CurrencyExchange>))]
+    public List<CurrencyExchange>? CurrencyExchange { get; }
 
     /// <summary>
     /// The identification of the transaction as used for reference by the financial institution.
@@ -343,7 +345,7 @@ public Transaction(string? transactionId, string? debtorName, MinimalBankAccount
         DateTime? valueDateTime, string? remittanceInformationStructured,
         IEnumerable<string>? remittanceInformationStructuredArray, string? additionalInformation,
         string? additionalInformationStructured, Balance? balanceAfterTransaction, string? checkId,
-        IEnumerable<CurrencyExchange>? currencyExchange, string? entryReference, string? internalTransactionId,
+        List<CurrencyExchange>? currencyExchange, string? entryReference, string? internalTransactionId,
         string? merchantCategoryCode, DateTime? bookingDateTime)
     {
         TransactionId = transactionId;