Change order of else-if null/undefined check

Author: MichalLytek

src/driver/express/ExpressDriver.ts

@@ -278,29 +278,29 @@ export class ExpressDriver extends BaseDriver implements Driver {
                 options.next();
             });
         } 
-        else if (result != null) { // send regular result
-            if (action.isJsonTyped) {
-                options.response.json(result);
-            } else {
-                options.response.send(result);
-            }
-            options.next();
-        }
         else if (result === undefined) { // throw NotFoundError on undefined response
             const notFoundError = new NotFoundError();
             if (action.undefinedResultCode) {
                 notFoundError.httpCode = action.undefinedResultCode as number;
             }
             throw notFoundError;
         }
-        else { // send null response
+        else if (result === null) { // send null response
             if (action.isJsonTyped) {
                 options.response.json(null);
             } else {
                 options.response.send(null);
             }
             options.next();
         }
+        else { // send regular result
+            if (action.isJsonTyped) {
+                options.response.json(result);
+            } else {
+                options.response.send(result);
+            }
+            options.next();
+        }
     }
 
     /**

src/driver/koa/KoaDriver.ts

@@ -247,36 +247,36 @@ export class KoaDriver extends BaseDriver implements Driver {
 
             return options.next();
         }
-        else if (result != null) { // send regular result
-            if (result instanceof Object) {
-                options.response.body = result;
-            } else {
-                options.response.body = result;
-            }
-
-            return options.next();
-        }
         else if (result === undefined) { // throw NotFoundError on undefined response
             const notFoundError = new NotFoundError();
             if (action.undefinedResultCode) {
                 notFoundError.httpCode = action.undefinedResultCode as number;
             }
             throw notFoundError;
         }
-        else { // send null response
+        else if (result === null) { // send null response
             if (action.isJsonTyped) {
                 options.response.body = null;
             } else {
                 options.response.body = null;
             }
-
+            
             // Setting `null` as a `response.body` means to koa that there is no content to return
             // so we must reset the status codes here.
             if (action.nullResultCode) {
                 options.response.status = action.nullResultCode;
             } else {
                 options.response.status = 204;
             }
+            
+            return options.next();
+        }
+        else { // send regular result
+            if (result instanceof Object) {
+                options.response.body = result;
+            } else {
+                options.response.body = result;
+            }
 
             return options.next();
         }