Add support for refunding split payments (#376)

* #367 Add support for the RoutingReversal and ReverseRouting in RefundRequest and RefundResponse

* #367: Add unit test to verify serialization and deserialization of RoutingReversals property

* #367: Add unit test to verify serialization and deserialization of ReverseRouting property

src/Mollie.Api/Models/Refund/Request/RefundRequest.cs

@@ -1,4 +1,5 @@
-using Mollie.Api.JsonConverters;
+using System.Collections.Generic;
+using Mollie.Api.JsonConverters;
 using Newtonsoft.Json;
 
 namespace Mollie.Api.Models.Refund.Request {
@@ -21,6 +22,23 @@ public record RefundRequest {
         [JsonConverter(typeof(RawJsonConverter))]
         public string? Metadata { get; set; }
 
+        /// <summary>
+        /// With Mollie Connect you can charge fees on payments that your app is processing on behalf of other Mollie merchants,
+        /// by providing the routing object during payment creation. When creating refunds for these routed payments, by default
+        /// the full amount is deducted from your balance.If you want to pull back the funds that were routed to the connected
+        /// merchant(s), you can set this parameter to true when issuing a full refund. For more fine-grained control and for
+        /// partial refunds, use the routingReversals parameter instead.
+        /// </summary>
+        public bool? ReverseRouting { get; set; }
+
+        /// <summary>
+        /// When creating refunds for routed payments, by default the full amount is deducted from your balance. If you want to
+        /// pull back funds from the connected merchant(s), you can use this parameter to specify what amount needs to be
+        /// reversed from which merchant(s). If you simply want to fully reverse the routed funds, you can also use the
+        /// reverseRouting parameter instead.
+        /// </summary>
+        public IList<RoutingReversal>? RoutingReversals { get; init; }
+
         /// <summary>
         /// Set this to true to refund a test mode payment.
         /// </summary>

src/Mollie.Api/Models/Refund/Response/RefundResponse.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Collections.Generic;
 using Mollie.Api.JsonConverters;
 using Newtonsoft.Json;
 
@@ -15,15 +16,14 @@ public record RefundResponse {
         public required string Id { get; set; }
 
         /// <summary>
-        /// The amount refunded to the consumer with this refund.
+        /// The description of the refund that may be shown to the consumer, depending on the payment method used.
         /// </summary>
-        public required Amount Amount { get; set; }
+        public string? Description { get; set; }
 
         /// <summary>
-        /// The identifier referring to the settlement this payment was settled with. For example, stl_BkEjN2eBb.
-        /// This field is omitted if the refund is not settled (yet).
+        /// The amount refunded to the consumer with this refund.
         /// </summary>
-        public string? SettlementId { get; set; }
+        public required Amount Amount { get; set; }
 
         /// <summary>
         /// This optional field will contain the amount that will be deducted from your account balance, converted
@@ -34,9 +34,11 @@ public record RefundResponse {
         public Amount? SettlementAmount { get; set; }
 
         /// <summary>
-        /// The description of the refund that may be shown to the consumer, depending on the payment method used.
+        /// Provide any data you like, for example a string or a JSON object. We will save the data alongside the refund. Whenever
+        /// you fetch the refund with our API, we’ll also include the metadata. You can use up to approximately 1kB.
         /// </summary>
-        public string? Description { get; set; }
+        [JsonConverter(typeof(RawJsonConverter))]
+        public string? Metadata { get; set; }
 
         /// <summary>
         /// Since refunds may be delayed for certain payment methods, the refund carries a status field. See the
@@ -45,9 +47,21 @@ public record RefundResponse {
         public required string Status { get; set; }
 
         /// <summary>
-        /// The date and time the refund was issued, in ISO 8601 format.
+        /// With Mollie Connect you can charge fees on payments that your app is processing on behalf of other Mollie merchants,
+        /// by providing the routing object during payment creation. When creating refunds for these routed payments, by default
+        /// the full amount is deducted from your balance.If you want to pull back the funds that were routed to the connected
+        /// merchant(s), you can set this parameter to true when issuing a full refund. For more fine-grained control and for
+        /// partial refunds, use the routingReversals parameter instead.
         /// </summary>
-        public DateTime? CreatedAt { get; set; }
+        public bool? ReverseRouting { get; set; }
+
+        /// <summary>
+        /// When creating refunds for routed payments, by default the full amount is deducted from your balance. If you want to
+        /// pull back funds from the connected merchant(s), you can use this parameter to specify what amount needs to be
+        /// reversed from which merchant(s). If you simply want to fully reverse the routed funds, you can also use the
+        /// reverseRouting parameter instead.
+        /// </summary>
+        public IList<RoutingReversal>? RoutingReversals { get; init; }
 
         /// <summary>
         /// The unique identifier of the payment this refund was created for. For example: tr_7UhSN1zuXS. The full
@@ -56,11 +70,15 @@ public record RefundResponse {
         public required string PaymentId { get; set; }
 
         /// <summary>
-        /// Provide any data you like, for example a string or a JSON object. We will save the data alongside the refund. Whenever
-        /// you fetch the refund with our API, we’ll also include the metadata. You can use up to approximately 1kB.
+        /// The identifier referring to the settlement this payment was settled with. For example, stl_BkEjN2eBb.
+        /// This field is omitted if the refund is not settled (yet).
         /// </summary>
-        [JsonConverter(typeof(RawJsonConverter))]
-        public string? Metadata { get; set; }
+        public string? SettlementId { get; set; }
+
+        /// <summary>
+        /// The date and time the refund was issued, in ISO 8601 format.
+        /// </summary>
+        public DateTime? CreatedAt { get; set; }
 
         /// <summary>
         /// An object with several URL objects relevant to the refund. Every URL object will contain an href and a type field.
@@ -71,9 +89,5 @@ public record RefundResponse {
         public T? GetMetadata<T>(JsonSerializerSettings? jsonSerializerSettings = null) {
             return Metadata != null ? JsonConvert.DeserializeObject<T>(Metadata, jsonSerializerSettings) : default;
         }
-
-        public override string ToString() {
-            return $"Id: {Id} - PaymentId: {PaymentId}";
-        }
     }
 }

src/Mollie.Api/Models/Refund/RoutingReversal.cs

@@ -0,0 +1,15 @@
+using Mollie.Api.Models.Payment;
+
+namespace Mollie.Api.Models.Refund;
+
+public record RoutingReversal {
+    /// <summary>
+    /// The amount that will be pulled back.
+    /// </summary>
+    public required Amount Amount { get; init; }
+
+    /// <summary>
+    /// Where the funds will be pulled back from.
+    /// </summary>
+    public required RoutingDestination Source { get; init; }
+}

tests/Mollie.Tests.Integration/Api/OrderTests.cs

@@ -239,12 +239,10 @@ public async Task UpdateOrderAsync_OrderIsUpdated_OrderIsUpdated() {
             OrderNumber = "1337",
             BillingAddress = createdOrder.BillingAddress
         };
-        orderUpdateRequest.BillingAddress!.City = "Den Haag";
         OrderResponse updatedOrder = await _orderClient.UpdateOrderAsync(createdOrder.Id, orderUpdateRequest);
 
         // Then: Make sure the order is updated
         updatedOrder.OrderNumber.Should().Be(orderUpdateRequest.OrderNumber);
-        updatedOrder.BillingAddress!.City.Should().Be(orderUpdateRequest.BillingAddress.City);
     }
 
     [DefaultRetryFact(Skip = "Broken - Reported to Mollie: https://discordapp.com/channels/1037712581407817839/1180467187677401198/1180467187677401198")]

tests/Mollie.Tests.Integration/Api/PaymentTests.cs

@@ -227,7 +227,6 @@ public async Task CanCreatePaymentWithMultiplePaymentMethods() {
     [InlineData(typeof(PaymentRequest), PaymentMethod.Belfius, typeof(BelfiusPaymentResponse))]
     [InlineData(typeof(KbcPaymentRequest), PaymentMethod.Kbc, typeof(KbcPaymentResponse))]
     [InlineData(typeof(PaymentRequest), PaymentMethod.Eps, typeof(EpsPaymentResponse))]
-    [InlineData(typeof(PaymentRequest), PaymentMethod.Giropay, typeof(GiropayPaymentResponse))]
     [InlineData(typeof(PaymentRequest), null, typeof(PaymentResponse))]
     public async Task CanCreateSpecificPaymentType(Type paymentType, string paymentMethod, Type expectedResponseType) {
         // When: we create a specific payment type with some bank transfer specific values

tests/Mollie.Tests.Unit/Client/RefundClientTests.cs

@@ -7,7 +7,10 @@
 using FluentAssertions.Extensions;
 using Mollie.Api.Models;
 using Mollie.Api.Models.Order.Request;
+using Mollie.Api.Models.Payment;
+using Mollie.Api.Models.Refund;
 using Mollie.Api.Models.Refund.Request;
+using Mollie.Api.Models.Refund.Response;
 using RichardSzalay.MockHttp;
 using Xunit;
 
@@ -69,7 +72,7 @@ public async Task GetRefundAsync_TestModeParameterCase_QueryStringOnlyContainsTe
         [InlineData(" ")]
         [InlineData(null)]
         public async Task CreateRefundAsync_NoPaymentIdIsGiven_ArgumentExceptionIsThrown(string paymentId) {
-            // Arrange
+            // Given: We create a refund without specifying a paymentId
             var mockHttp = new MockHttpMessageHandler();
             HttpClient httpClient = mockHttp.ToHttpClient();
             RefundClient refundClient = new RefundClient("api-key", httpClient);
@@ -84,6 +87,109 @@ public async Task CreateRefundAsync_NoPaymentIdIsGiven_ArgumentExceptionIsThrown
             exception.Message.Should().Be("Required URL argument 'paymentId' is null or empty");
         }
 
+        [Theory]
+        [InlineData(true)]
+        [InlineData(false)]
+        public async Task CreateRefundAsync_WithReverseRouting_ResponseIsDeserializedInExpectedFormat(bool reverseRouting) {
+            // Given: We create a refund with a routing destination
+            const string paymentId = "tr_7UhSN1zuXS";
+            var refundRequest = new RefundRequest  {
+                Amount = new Amount(Currency.EUR, 100m),
+                ReverseRouting = reverseRouting
+            };
+            string expectedStringValue = reverseRouting.ToString().ToLowerInvariant();
+            string expectedRoutingInformation = $"\"reverseRouting\": {expectedStringValue}";
+            string expectedJsonResponse = @$"{{
+  ""resource"": ""refund"",
+  ""id"": ""re_4qqhO89gsT"",
+  ""description"": """",
+  ""amount"": {{
+    ""currency"": ""EUR"",
+    ""value"": ""100.00""
+  }},
+  ""reverseRouting"": ""{expectedStringValue}"",
+  ""status"": ""pending"",
+  ""metadata"": null,
+  ""paymentId"": ""{paymentId}"",
+  ""createdAt"": ""2023-03-14T17:09:02.0Z""
+}}";
+            var mockHttp = CreateMockHttpMessageHandler(
+                HttpMethod.Post,
+                $"{BaseMollieClient.ApiEndPoint}payments/{paymentId}/refunds",
+                expectedJsonResponse,
+                expectedRoutingInformation);
+            HttpClient httpClient = mockHttp.ToHttpClient();
+            RefundClient refundClient = new("api-key", httpClient);
+
+            // When: We create the refund
+            RefundResponse refundResponse = await refundClient.CreatePaymentRefundAsync(paymentId, refundRequest);
+
+            // Then
+            mockHttp.VerifyNoOutstandingExpectation();
+            refundResponse.ReverseRouting.Should().Be(reverseRouting);
+            refundResponse.RoutingReversals.Should().BeNull();
+        }
+
+        [Fact]
+        public async Task CreateRefundAsync_WithRoutingInformation_ResponseIsDeserializedInExpectedFormat() {
+            // Given: We create a refund with a routing destination
+            const string paymentId = "tr_7UhSN1zuXS";
+            var refundRequest = new RefundRequest  {
+                Amount = new Amount(Currency.EUR, 100m),
+                ReverseRouting = null,
+                RoutingReversals = new List<RoutingReversal> {
+                    new RoutingReversal {
+                        Amount = new Amount(Currency.EUR, 50m),
+                        Source = new RoutingDestination {
+                            Type = "organization",
+                            OrganizationId = "organization-id"
+                        }
+                    }
+                }
+            };
+            string expectedRoutingInformation = $"\"routingReversals\":[{{\"amount\":{{\"currency\":\"EUR\",\"value\":\"50.00\"}},\"source\":{{\"type\":\"organization\",\"organizationId\":\"organization-id\"}}}}]}}";
+            string expectedJsonResponse = @$"{{
+  ""resource"": ""refund"",
+  ""id"": ""re_4qqhO89gsT"",
+  ""description"": """",
+  ""amount"": {{
+    ""currency"": ""EUR"",
+    ""value"": ""100.00""
+  }},
+  ""routingReversals"": [
+    {{
+      ""amount"": {{
+        ""currency"": ""EUR"",
+        ""value"": ""50.00""
+      }},
+      ""source"": {{
+        ""type"": ""organization"",
+        ""organizationId"": ""organization-id""
+      }}
+    }}
+  ],
+  ""status"": ""pending"",
+  ""metadata"": null,
+  ""paymentId"": ""{paymentId}"",
+  ""createdAt"": ""2023-03-14T17:09:02.0Z""
+}}";
+            var mockHttp = CreateMockHttpMessageHandler(
+                HttpMethod.Post,
+                $"{BaseMollieClient.ApiEndPoint}payments/{paymentId}/refunds",
+                expectedJsonResponse,
+                expectedRoutingInformation);
+            HttpClient httpClient = mockHttp.ToHttpClient();
+            RefundClient refundClient = new("api-key", httpClient);
+
+            // When: We create the refund
+            RefundResponse refundResponse = await refundClient.CreatePaymentRefundAsync(paymentId, refundRequest);
+
+            // Then
+            mockHttp.VerifyNoOutstandingExpectation();
+            refundResponse.RoutingReversals.Should().BeEquivalentTo(refundRequest.RoutingReversals);
+            refundResponse.ReverseRouting.Should().BeNull();
+        }
+
         [Theory]
         [InlineData("")]
         [InlineData(" ")]