fix (invoke-handler) error with string code causes exception on server

Author: vengrov

lib/server-code/runners/tasks/util/result-wrapper.js

@@ -20,15 +20,16 @@ exports.invocationResult = function(err, args) {
   };
 };
 
-
 /**
  * @param {?Error|ExceptionWrapper|String} err
  * @returns {Object}
  */
 exports.exception = function(err) {
+  const errCode = typeof err.code === 'number' ? err.code : 0;
+  
   return {
     ___jsonclass    : err.___jsonclass || 'com.backendless.commons.exception.ExceptionWrapper',
-    code            : err.code || 0,
+    code            : errCode,
     exceptionClass  : err.exceptionClass || 'java.lang.Exception',
     exceptionMessage: err.exceptionMessage || err.message || err
   };

test/invoke-handler-task.js

@@ -141,6 +141,21 @@ describe('[invoke-handler] task executor', function() {
       });
     });
 
+    it('and escape string error code', function() {
+      function handler() {
+        const err = new Error('StreamError');
+        err.code = 'ENOTFOUND';
+
+        throw err;
+      }
+
+      return invokeAndParse(createTask(BEFORE_CREATE), modelStub(handler)).then(res => {
+        should.exist(res.exception);
+        res.exception.code.should.equal(0);
+        res.exception.exceptionMessage.should.equal('StreamError');
+      });
+    });
+
     it('async errors raised in the event handler behind the promise', function() {
       function handler() {
         process.nextTick(() => {