fix: Use JSON serializer extracted from the DI container to serialize error responses (#1713)

Author: 96malhar

Libraries/src/Amazon.Lambda.Annotations.SourceGenerator/Templates/APIGatewaySetupParameters.cs

@@ -299,7 +299,8 @@
                 {
 #>
                 var errorStream = new System.IO.MemoryStream();
-                System.Text.Json.JsonSerializer.Serialize(errorStream, errorResult);
+                serializer.Serialize(errorResult, errorStream);
+                errorStream.Position = 0;
                 return errorStream;
 <#
                 }

Libraries/src/Amazon.Lambda.Annotations.SourceGenerator/Templates/APIGatewaySetupParameters.tt

@@ -52,7 +52,8 @@ public CustomizeResponseExamples_NotFoundResponseWithHeaderV1Async_Generated()
                     StatusCode = 400
                 };
                 var errorStream = new System.IO.MemoryStream();
-                System.Text.Json.JsonSerializer.Serialize(errorStream, errorResult);
+                serializer.Serialize(errorResult, errorStream);
+                errorStream.Position = 0;
                 return errorStream;
             }
 

Libraries/test/Amazon.Lambda.Annotations.SourceGenerators.Tests/Snapshots/CustomizeResponseExamples_NotFoundResponseWithHeaderV1Async_Generated.g.cs

@@ -52,7 +52,8 @@ public System.IO.Stream NotFoundResponseWithHeaderV1(Amazon.Lambda.APIGatewayEve
                     StatusCode = 400
                 };
                 var errorStream = new System.IO.MemoryStream();
-                System.Text.Json.JsonSerializer.Serialize(errorStream, errorResult);
+                serializer.Serialize(errorResult, errorStream);
+                errorStream.Position = 0;
                 return errorStream;
             }
 

Libraries/test/Amazon.Lambda.Annotations.SourceGenerators.Tests/Snapshots/CustomizeResponseExamples_NotFoundResponseWithHeaderV1_Generated.g.cs

@@ -52,7 +52,8 @@ public CustomizeResponseExamples_NotFoundResponseWithHeaderV2Async_Generated()
                     StatusCode = 400
                 };
                 var errorStream = new System.IO.MemoryStream();
-                System.Text.Json.JsonSerializer.Serialize(errorStream, errorResult);
+                serializer.Serialize(errorResult, errorStream);
+                errorStream.Position = 0;
                 return errorStream;
             }
 

Libraries/test/Amazon.Lambda.Annotations.SourceGenerators.Tests/Snapshots/CustomizeResponseExamples_NotFoundResponseWithHeaderV2Async_Generated.g.cs

@@ -52,7 +52,8 @@ public System.IO.Stream NotFoundResponseWithHeaderV2(Amazon.Lambda.APIGatewayEve
                     StatusCode = 400
                 };
                 var errorStream = new System.IO.MemoryStream();
-                System.Text.Json.JsonSerializer.Serialize(errorStream, errorResult);
+                serializer.Serialize(errorResult, errorStream);
+                errorStream.Position = 0;
                 return errorStream;
             }
 

Libraries/test/Amazon.Lambda.Annotations.SourceGenerators.Tests/Snapshots/CustomizeResponseExamples_NotFoundResponseWithHeaderV2_Generated.g.cs

@@ -52,7 +52,8 @@ public CustomizeResponseExamples_OkResponseWithHeaderAsync_Generated()
                     StatusCode = 400
                 };
                 var errorStream = new System.IO.MemoryStream();
-                System.Text.Json.JsonSerializer.Serialize(errorStream, errorResult);
+                serializer.Serialize(errorResult, errorStream);
+                errorStream.Position = 0;
                 return errorStream;
             }
 

Libraries/test/Amazon.Lambda.Annotations.SourceGenerators.Tests/Snapshots/CustomizeResponseExamples_OkResponseWithHeaderAsync_Generated.g.cs

@@ -52,7 +52,8 @@ public System.IO.Stream OkResponseWithHeader(Amazon.Lambda.APIGatewayEvents.APIG
                     StatusCode = 400
                 };
                 var errorStream = new System.IO.MemoryStream();
-                System.Text.Json.JsonSerializer.Serialize(errorStream, errorResult);
+                serializer.Serialize(errorResult, errorStream);
+                errorStream.Position = 0;
                 return errorStream;
             }
 

Libraries/test/Amazon.Lambda.Annotations.SourceGenerators.Tests/Snapshots/CustomizeResponseExamples_OkResponseWithHeader_Generated.g.cs

@@ -0,0 +1,41 @@
+using Newtonsoft.Json.Linq;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using Xunit;
+
+namespace TestServerlessApp.IntegrationTests
+{
+    [Collection("Integration Tests")]
+    public class CustomResponse
+    {
+        private readonly IntegrationTestContextFixture _fixture;
+
+        public CustomResponse(IntegrationTestContextFixture fixture)
+        {
+            _fixture = fixture;
+        }
+
+        [Fact]
+        public async Task OkResponseWithHeader_Returns200Status()
+        {
+            var response = await _fixture.HttpClient.GetAsync($"{_fixture.RestApiUrlPrefix}/okresponsewithheader/1");
+            response.EnsureSuccessStatusCode();
+            Assert.Equal("All Good", await response.Content.ReadAsStringAsync());
+        }
+
+        [Fact]
+        public async Task OkResponseWithHeader_ReturnsValidationErrors()
+        {
+            var response = await _fixture.HttpClient.GetAsync($"{_fixture.RestApiUrlPrefix}/okresponsewithheader/hello");
+            Assert.Equal(400, (int)response.StatusCode);
+            var content = await response.Content.ReadAsStringAsync();
+            var errorJson = JObject.Parse(content);
+
+            var expectedErrorMessage = "1 validation error(s) detected: Value hello at 'x' failed to satisfy constraint: Input string was not in a correct format.";
+            Assert.Equal(expectedErrorMessage, errorJson["message"]);
+        }
+    }
+}