Include err.message and err.name for debug data

err.message and err.name are not enumerable,
therefore needs to be explicited added to the data obj

lib/data-builder.js

@@ -16,9 +16,10 @@ module.exports = function buildResponseData(err, isDebugMode) {
   fillStatusCode(data, err);
 
   if (typeof err !== 'object') {
-    data.statusCode = 500;
-    data.message = '' + err;
-    err = {};
+    err = {
+      statusCode: 500,
+      message: '' + err,
+    };
   }
 
   if (isDebugMode) {
@@ -41,10 +42,8 @@ function serializeArrayOfErrors(errors) {
       continue;
     }
 
-    var data = {stack: err.stack};
-    for (var p in err) { // eslint-disable-line one-var
-      data[p] = err[p];
-    }
+    var data = {};
+    cloneAllProperties(data, err);
     details.push(data);
   }
 
@@ -63,12 +62,7 @@ function fillStatusCode(data, err) {
 }
 
 function fillDebugData(data, err) {
-  for (var p in err) {
-    if ((p in data)) continue;
-    data[p] = err[p];
-  }
-  // NOTE err.stack is not an enumerable property
-  data.stack = err.stack;
+  cloneAllProperties(data, err);
 }
 
 function fillBadRequestError(data, err) {
@@ -80,3 +74,16 @@ function fillBadRequestError(data, err) {
 function fillInternalError(data, err) {
   data.message = httpStatus[data.statusCode] || 'Unknown Error';
 }
+
+function cloneAllProperties(data, err) {
+  // NOTE err.name and err.message are not enumerable properties
+  data.name = err.name;
+  data.message = err.message;
+  for (var p in err) {
+    if ((p in data)) continue;
+    data[p] = err[p];
+  }
+  // NOTE err.stack is not an enumerable property
+  // stack is appended last to ensure order is the same for response
+  data.stack = err.stack;
+}

test/handler.test.js

@@ -191,6 +191,7 @@ describe('strong-error-handler', function() {
   context('JSON response', function() {
     it('contains all error properties when debug=true', function(done) {
       var error = new ErrorWithProps({
+        message: 'a test error message',
         details: 'some details',
         extra: 'sensitive data',
       });
@@ -199,15 +200,36 @@ describe('strong-error-handler', function() {
       requestJson().end(function(err, res) {
         if (err) return done(err);
 
-        var expectedData = {statusCode: 500, stack: error.stack};
-        for (var key in error) expectedData[key] = error[key];
-
+        var expectedData = {
+          statusCode: 500,
+          message: 'a test error message',
+          name: 'ErrorWithProps',
+          details: 'some details',
+          extra: 'sensitive data',
+          stack: error.stack,
+        };
         expect(res.body).to.have.property('error');
         expect(res.body.error).to.eql(expectedData);
         done();
       });
     });
 
+    it('contains non-enumerable Error properties when debug=true',
+      function(done) {
+        var error = new Error('a test error message');
+        givenErrorHandlerForError(error, {debug: true});
+        requestJson().end(function(err, res) {
+          if (err) return done(err);
+          expect(res.body).to.have.property('error');
+          var resError = res.body.error;
+          expect(resError).to.have.property('name', 'Error');
+          expect(resError).to.have.property('message',
+            'a test error message');
+          expect(resError).to.have.property('stack', error.stack);
+          done();
+        });
+      });
+
     it('contains subset of properties when status=4xx', function(done) {
       var error = new ErrorWithProps({
         name: 'ValidationError',