Additional unit tests on Jersey to validate that it honors the produces annotations (#250)

Author: sapessi

aws-serverless-java-container-jersey/src/test/java/com/amazonaws/serverless/proxy/jersey/EchoJerseyResource.java

@@ -41,6 +41,7 @@
 import java.io.IOException;
 import java.io.InputStream;
 import java.util.Enumeration;
+import java.util.HashMap;
 import java.util.List;
 import java.util.Random;
 
@@ -272,4 +273,11 @@ public Response fileSize(@FormDataParam("file") final File uploadedFile,
             return Response.status(500).build();
         }
     }
+
+    @Path("/plain") @GET
+    @Produces(MediaType.TEXT_PLAIN)
+    @Consumes(MediaType.APPLICATION_JSON)
+    public Response plain() {
+        return Response.status(200).entity("Hello!").build();
+    }
 }

aws-serverless-java-container-jersey/src/test/java/com/amazonaws/serverless/proxy/jersey/JerseyAwsProxyTest.java

@@ -363,6 +363,20 @@ public void refererHeader_headerParam_expectCorrectInjection() {
         validateSingleValueModel(resp, refererValue);
     }
 
+    @Test
+    public void textPlainContent_plain_responseHonorsContentType() {
+        AwsProxyRequest req = getRequestBuilder("/echo/plain", "GET")
+                                            .nullBody()
+                                            .header(HttpHeaders.CONTENT_TYPE, MediaType.APPLICATION_JSON)
+                                            .header(HttpHeaders.ACCEPT, MediaType.TEXT_PLAIN)
+                                            .build();
+
+        AwsProxyResponse resp = handler.proxy(req, lambdaContext);
+        assertEquals(200, resp.getStatusCode());
+        assertTrue(resp.getMultiValueHeaders().containsKey(HttpHeaders.CONTENT_TYPE));
+        assertEquals(MediaType.TEXT_PLAIN, resp.getMultiValueHeaders().get(HttpHeaders.CONTENT_TYPE).get(0));
+    }
+
     private void validateMapResponseModel(AwsProxyResponse output) {
         validateMapResponseModel(output, CUSTOM_HEADER_KEY, CUSTOM_HEADER_VALUE);
     }