Add a PostDocumentAsync with extra generic for new doc type.

arangodb-net-standard.Test/DocumentApi/DocumentApiClientTest.cs

@@ -430,6 +430,26 @@ public async Task PostDocument_ShouldSucceed_WhenNewDocIsReturned()
             Assert.Equal(123, (int)response.New.test);
         }
 
+        [Fact]
+        public async Task PostDocument_ShouldSucceed_WhenNewDocIsReturnedWithDifferentType()
+        {
+            var doc = new PostDocumentMockModelNew
+            {
+                Message = "Hello"
+            };
+            var response = await _docClient.PostDocumentAsync<PostDocumentMockModelNew, PostDocumentMockModel>(
+                _testCollection,
+                doc,
+                new PostDocumentsQuery
+                {
+                    ReturnNew = true
+                });
+            Assert.Null(response.Old);
+            Assert.NotNull(response.New);
+            Assert.Equal(doc.Message, response.New.Message);
+            Assert.Equal(response._id, response.New._id);
+        }
+
         [Fact]
         public async Task PostDocument_ShouldFail_WhenDocumentIsInvalid()
         {

arangodb-net-standard.Test/DocumentApi/Models/PostDocumentMockModel.cs

@@ -0,0 +1,9 @@
+using ArangoDBNetStandard.DocumentApi.Models;
+
+namespace ArangoDBNetStandardTest.DocumentApi.Models
+{
+    public class PostDocumentMockModel : DocumentBase
+    {
+        public string Message { get; set; }
+    }
+}

arangodb-net-standard.Test/DocumentApi/Models/PostDocumentMockModelNew.cs

@@ -0,0 +1,9 @@
+using System.Collections.Generic;
+
+namespace ArangoDBNetStandardTest.DocumentApi.Models
+{
+    public class PostDocumentMockModelNew
+    {
+        public string Message { get; set; }
+    }
+}

arangodb-net-standard/DocumentApi/DocumentApiClient.cs

@@ -55,7 +55,34 @@ public DocumentApiClient(IApiClientTransport client, IApiClientSerialization ser
         /// <param name="serializationOptions">The serialization options. When the value is null the
         /// the serialization options should be provided by the serializer, otherwise the given options should be used.</param>
         /// <returns></returns>
-        public virtual async Task<PostDocumentResponse<T>> PostDocumentAsync<T>(
+        public virtual Task<PostDocumentResponse<T>> PostDocumentAsync<T>(
+            string collectionName,
+            T document,
+            PostDocumentsQuery query = null,
+            ApiClientSerializationOptions serializationOptions = null)
+        {
+            return PostDocumentAsync<T, T>(
+                collectionName,
+                document,
+                query,
+                serializationOptions);
+        }
+
+        /// <summary>
+        /// Post a single document with the possibility to specify a different type
+        /// for the new document object returned in the response.
+        /// </summary>
+        /// <typeparam name="T">The type of the post object used to record a new document.</typeparam>
+        /// <typeparam name="U">Type of the returned document, only applies when
+        /// <see cref="PostDocumentsQuery.ReturnNew"/> or <see cref="PostDocumentsQuery.ReturnOld"/>
+        /// are used.</typeparam>
+        /// <param name="collectionName"></param>
+        /// <param name="document"></param>
+        /// <param name="query"></param>
+        /// <param name="serializationOptions">The serialization options. When the value is null the
+        /// the serialization options should be provided by the serializer, otherwise the given options should be used.</param>
+        /// <returns></returns>
+        public virtual async Task<PostDocumentResponse<U>> PostDocumentAsync<T, U>(
             string collectionName,
             T document,
             PostDocumentsQuery query = null,
@@ -72,7 +99,7 @@ public virtual async Task<PostDocumentResponse<T>> PostDocumentAsync<T>(
                 if (response.IsSuccessStatusCode)
                 {
                     var stream = await response.Content.ReadAsStreamAsync();
-                    return DeserializeJsonFromStream<PostDocumentResponse<T>>(stream);
+                    return DeserializeJsonFromStream<PostDocumentResponse<U>>(stream);
                 }
                 throw await GetApiErrorException(response);
             }

arangodb-net-standard/DocumentApi/IDocumentApiClient.cs

@@ -14,7 +14,7 @@ public interface IDocumentApiClient
         /// <summary>
         /// Post a single document.
         /// </summary>
-        /// <typeparam name="T"></typeparam>
+        /// <typeparam name="T">The type of the post object used to record a new document.</typeparam>
         /// <param name="collectionName"></param>
         /// <param name="document"></param>
         /// <param name="query"></param>
@@ -27,6 +27,26 @@ Task<PostDocumentResponse<T>> PostDocumentAsync<T>(
            PostDocumentsQuery query = null,
            ApiClientSerializationOptions serializationOptions = null);
 
+        /// <summary>
+        /// Post a single document with the possibility to specify a different type
+        /// for the new document object returned in the response.
+        /// </summary>
+        /// <typeparam name="T">The type of the post object used to record a new document.</typeparam>
+        /// <typeparam name="U">Type of the returned document, only applies when
+        /// <see cref="PostDocumentsQuery.ReturnNew"/> or <see cref="PostDocumentsQuery.ReturnOld"/>
+        /// are used.</typeparam>
+        /// <param name="collectionName"></param>
+        /// <param name="document"></param>
+        /// <param name="query"></param>
+        /// <param name="serializationOptions">The serialization options. When the value is null the
+        /// the serialization options should be provided by the serializer, otherwise the given options should be used.</param>
+        /// <returns></returns>
+        Task<PostDocumentResponse<U>> PostDocumentAsync<T, U>(
+           string collectionName,
+           T document,
+           PostDocumentsQuery query = null,
+           ApiClientSerializationOptions serializationOptions = null);
+
         /// <summary>
         /// Post multiple documents in a single request.
         /// </summary>