Added support for node 4

.eslintrc.yml

@@ -4,9 +4,14 @@ plugins:
 
 env:
   mocha: true
-
+  node: true
 
 rules:
   padded-blocks: off
   no-trailing-spaces: [error, skipBlankLines: true]
   comma-dangle: [error, never]
+
+  # Doesn't work in node v4
+  strict: off
+  prefer-rest-params: off
+  prefer-spread: off

.travis.yml

@@ -1,6 +1,7 @@
 language: node_js
 
 node_js:
+  - "4"
   - "6"
 
 # For code coverage:

src/index.js

@@ -1,3 +1,4 @@
+'use strict';
 
 const BbPromise = require('bluebird');
 

tests/index.test.js

@@ -1,4 +1,4 @@
-
+'use strict';
 
 const expect = require('expect.js');
 const Plugin = require('../src/index.js');
@@ -50,17 +50,19 @@ describe('serverless-plugin-lambda-dead-letter', () => {
 
   function createMockRequest(requestStub) {
 
-    return (...reqArgs) =>
+    return () => {
 
-      new BbPromise((resolve, reject) => {
-        const result = requestStub(...reqArgs);
+      const reqArgs = Array.prototype.slice.call(arguments);
+      return new BbPromise((resolve, reject) => {
+        const result = requestStub.apply(undefined, reqArgs);
         if (result !== null) {
           resolve(result);
           return;
         }
         reject(new Error(`Call to request() with unexpected arguments:  ${JSON.stringify(reqArgs)}`));
 
       });
+    };
 
 
   }