test(post): response header should contain location of new resource

Issue #21

Author: jaredcnance

src/JsonApiDotNetCore/Controllers/JsonApiController.cs

@@ -144,7 +144,7 @@ public virtual async Task<IActionResult> PostAsync([FromBody] T entity)
 
             await _entities.CreateAsync(entity);
 
-            return Created(HttpContext.Request.Path, entity);
+            return Created($"{HttpContext.Request.Path}/{entity.Id}", entity);
         }
 
         [HttpPatch("{id}")]

test/JsonApiDotNetCoreExampleTests/Acceptance/Spec/CreatingDataTests.cs

@@ -68,5 +68,42 @@ public async Task Request_With_ClientGeneratedId_Returns_403()
             // assert
             Assert.Equal(HttpStatusCode.Forbidden, response.StatusCode);
         }
+
+        [Fact]
+        public async Task PostRequest_ShouldReceiveLocationHeader_InResponse()
+        {
+            // arrange
+            var builder = new WebHostBuilder()
+                .UseStartup<Startup>();
+            var httpMethod = new HttpMethod("POST");
+            var route = "/api/v1/todo-items";
+            var server = new TestServer(builder);
+            var client = server.CreateClient();
+            var request = new HttpRequestMessage(httpMethod, route);
+            var todoItem = _todoItemFaker.Generate();
+            var content = new
+            {
+                data = new
+                {
+                    type = "todo-items",
+                    attributes = new
+                    {
+                        description = todoItem.Description,
+                        ordinal = todoItem.Ordinal
+                    }
+                }
+            };
+            request.Content = new StringContent(JsonConvert.SerializeObject(content));
+            request.Content.Headers.ContentType = new MediaTypeHeaderValue("application/vnd.api+json");
+            
+            // act
+            var response = await client.SendAsync(request);
+            var body = await response.Content.ReadAsStringAsync();
+            var deserializedBody = (TodoItem)JsonApiDeSerializer.Deserialize(body, _jsonApiContext);
+
+            // assert
+            Assert.Equal(HttpStatusCode.Created, response.StatusCode);
+            Assert.Equal($"/api/v1/todo-items/{deserializedBody.Id}", response.Headers.Location.ToString());
+        }
     }
 }