Fix already built incompatible payload thrown error

changelog.md

@@ -16,6 +16,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 - [Fix missing error of invalid inbound request parameter for forward() method](https://github.com/ballerina-platform/ballerina-standard-library/issues/311)
 - [Fix HTTP Circuit Breaker failure when status codes are not provided in the configuration](https://github.com/ballerina-platform/ballerina-standard-library/issues/339)
 - [Fix HTTP FailOver client failure when status codes are overridden by an empty array](https://github.com/ballerina-platform/ballerina-standard-library/issues/1598)
+- [Fix already built incompatible payload thrown error](https://github.com/ballerina-platform/ballerina-standard-library/issues/1600) 
 
 ### Changed
 - Rename `http:ListenerLdapUserStoreBasicAuthProvider` as `http:ListenerLdapUserStoreBasicAuthHandler`

http-ballerina-tests/tests/service_native_in_response_native_function_negative.bal

@@ -173,3 +173,63 @@ function negativeTestAddCookieWithInvalidMaxAge() {
     res.addCookie(cookie);
     test:assertEquals(res.getCookies().length(), 0, msg = "Output mismatched");
 }
+
+listener http:Listener inResponseCachedPayloadListener = new(inResponseCachedPayloadTestPort);
+listener http:Listener inResponseCachedPayloadBEListener = new(inResponseCachedPayloadTestBEPort);
+http:Client inRespCacheTestClient = check new("http://localhost:" + inResponseCachedPayloadTestPort.toString());
+
+service / on inResponseCachedPayloadListener {
+    resource function get checkJson() returns json|error {
+        http:Client diseaseEndpoint = check new ("http://localhost:" + inResponseCachedPayloadTestBEPort.toString());
+        http:Response resp = check diseaseEndpoint -> get("/getXml");
+        byte[] b = check resp.getBinaryPayload(); // represents cache behaviour
+        return resp.getJsonPayload();
+    }
+
+    resource function get checkXml() returns xml|error {
+        http:Client diseaseEndpoint = check new ("http://localhost:" + inResponseCachedPayloadTestBEPort.toString());
+        http:Response resp = check diseaseEndpoint -> get("/getJson");
+        byte[] b = check resp.getBinaryPayload(); // represents cache behaviour
+        return resp.getXmlPayload();
+    }
+}
+
+service / on inResponseCachedPayloadBEListener {
+    resource function get getXml(http:Caller caller) {
+        http:Response response = new;
+        xml xmlStr = xml `<name>Ballerina</name>`;
+        response.setXmlPayload(xmlStr);
+        error? result = caller->respond(response);
+    }
+
+    resource function get getJson(http:Caller caller) {
+        http:Response response = new;
+        json jsonStr = {"Ballerina" : "hello"};
+        response.setJsonPayload(jsonStr);
+        error? result = caller->respond(response);
+    }
+}
+
+@test:Config {}
+function testInRespGetJsonWhenAlreadyBuildBlobNegative() {
+    http:Response|error response = inRespCacheTestClient->get("/checkJson");
+    if (response is http:Response) {
+        test:assertEquals(response.statusCode, 500, msg = "Found unexpected output");
+        assertTextPayload(response.getTextPayload(), "Error occurred while retrieving the json payload from " +
+            "the response");
+    } else {
+        test:assertFail(msg = "Found unexpected output type: " + response.message());
+    }
+}
+
+@test:Config {}
+function testInRespGetXmlWhenAlreadyBuildBlobNegative() {
+    http:Response|error response = inRespCacheTestClient->get("/checkXml");
+    if (response is http:Response) {
+        test:assertEquals(response.statusCode, 500, msg = "Found unexpected output");
+        assertTextPayload(response.getTextPayload(), "Error occurred while retrieving the xml payload from " +
+            "the response");
+    } else {
+        test:assertFail(msg = "Found unexpected output type: " + response.message());
+    }
+}

http-ballerina-tests/tests/test_service_ports.bal

@@ -118,6 +118,8 @@ const int cBClientWithoutStatusCodesTestPort1 = 9569;
 const int cBClientWithoutStatusCodesTestPort2 = 9570;
 const int foClientWithoutStatusCodeTestPort1 = 9571;
 const int foClientWithoutStatusCodeTestPort2 = 9572;
+const int inResponseCachedPayloadTestPort = 9573;
+const int inResponseCachedPayloadTestBEPort = 9574;
 
 //HTTP2
 const int serverPushTestPort1 = 9601;

http-native/src/main/java/org/ballerinalang/net/http/nativeimpl/ExternHttpDataSourceBuilder.java

@@ -76,7 +76,7 @@ public static Object getNonBlockingByteArray(Environment env, BObject entityObj)
             balFuture = env.markAsync();
             constructNonBlockingDataSource(balFuture, entityObj, SourceType.BLOB);
         } catch (Exception exception) {
-            notifyError(balFuture, exception, "blob");
+            return notifyError(balFuture, exception, "blob");
         }
         return null;
     }
@@ -96,7 +96,7 @@ public static Object getNonBlockingJson(Environment env, BObject entityObj) {
              balFuture = env.markAsync();
             constructNonBlockingDataSource(balFuture, entityObj, SourceType.JSON);
         } catch (Exception exception) {
-            notifyError(balFuture, exception, "json");
+            return notifyError(balFuture, exception, "json");
         }
         return null;
     }
@@ -116,7 +116,7 @@ public static Object getNonBlockingText(Environment env, BObject entityObj) {
             balFuture = env.markAsync();
             constructNonBlockingDataSource(balFuture, entityObj, SourceType.TEXT);
         } catch (Exception exception) {
-            notifyError(balFuture, exception, "text");
+            return notifyError(balFuture, exception, "text");
         }
         return null;
     }
@@ -137,7 +137,7 @@ public static Object getNonBlockingXml(Environment env, BObject entityObj) {
             balFuture = env.markAsync();
             constructNonBlockingDataSource(balFuture, entityObj, SourceType.XML);
         } catch (Exception exception) {
-            notifyError(balFuture, exception, "xml");
+            return notifyError(balFuture, exception, "xml");
         }
         return null;
     }
@@ -210,9 +210,13 @@ public void onError(Exception ex) {
         });
     }
 
-    private static void notifyError(Future balFuture, Exception exception, String type) {
+    private static Object notifyError(Future balFuture, Exception exception, String type) {
         BError error = (BError) createError(exception, type);
-        setReturnValuesAndNotify(balFuture, error);
+        if (balFuture != null) {
+            setReturnValuesAndNotify(balFuture, error);
+            return null;
+        }
+        return error;
     }
 
     private static void createErrorAndNotify(Future balFuture, String errMsg) {