Allow passing in a promise dependency

.jshintrc

@@ -20,7 +20,6 @@
 
     "predef"        : [  // Extra globals.
         "__dirname",
-        "Promise",
         "Buffer",
         "event",
         "exports",

lib/caching.js

@@ -29,6 +29,8 @@ var caching = function(args) {
     // do we handle a cache error the same as a cache miss?
     self.ignoreCacheErrors = args.ignoreCacheErrors || false;
 
+    var Promise = args.promiseDependency || global.Promise;
+
     var callbackFiller = new CallbackFiller();
 
     if (typeof args.isCacheableValue === 'function') {

lib/multi_caching.js

@@ -19,6 +19,8 @@ var multiCaching = function(caches, options) {
     var self = {};
     options = options || {};
 
+    var Promise = options.promiseDependency || global.Promise;
+
     if (!Array.isArray(caches)) {
         throw new Error('multiCaching requires an array of caches');
     }

lib/stores/memory.js

@@ -4,6 +4,7 @@ var memoryStore = function(args) {
     args = args || {};
     var self = {};
     self.name = 'memory';
+    var Promise = args.promiseDependency || global.Promise;
     self.usePromises = (typeof Promise === 'undefined' || args.noPromises) ? false : true;
 
     var ttl = args.ttl;

test/caching.unit.js

@@ -8,6 +8,8 @@ var checkErr = support.checkErr;
 var caching = require('../index').caching;
 var memoryStore = require('../lib/stores/memory');
 
+var Promise = require('es6-promise').Promise;
+
 var methods = {
     getWidget: function(name, cb) {
         process.nextTick(function() {
@@ -27,7 +29,7 @@ describe("caching", function() {
         ['memory'].forEach(function(store) {
             context("using " + store + " store", function() {
                 beforeEach(function() {
-                    cache = caching({store: store});
+                    cache = caching({store: store, promiseDependency: Promise});
                     key = support.random.string(20);
                     value = support.random.string();
                 });

test/multi_caching.unit.js

@@ -7,6 +7,8 @@ var caching = require('../index').caching;
 var multiCaching = require('../index').multiCaching;
 var memoryStore = require('../lib/stores/memory');
 
+var Promise = require('es6-promise').Promise;
+
 var methods = {
     getWidget: function(name, cb) {
         process.nextTick(function() {
@@ -29,9 +31,9 @@ describe("multiCaching", function() {
         memoryTtl = 0.1;
         defaultTtl = 5;
 
-        memoryCache = caching({store: 'memory', ttl: memoryTtl});
+        memoryCache = caching({store: 'memory', ttl: memoryTtl, promiseDependency: Promise});
-        memoryCache2 = caching({store: 'memory', ttl: memoryTtl});
+        memoryCache2 = caching({store: 'memory', ttl: memoryTtl, promiseDependency: Promise});
-        memoryCache3 = caching({store: 'memory', ttl: memoryTtl});
+        memoryCache3 = caching({store: 'memory', ttl: memoryTtl, promiseDependency: Promise});
 
         key = support.random.string(20);
         name = support.random.string();

test/run.js

@@ -6,10 +6,6 @@ var Mocha = require('mocha');
 var optimist = require('optimist');
 var walkDir = require('./support').walkDir;
 
-if (typeof Promise === "undefined") {
-    global.Promise = require('es6-promise').Promise;
-}
-
 var argv = optimist
 .usage("Usage: $0 -t [types] --reporter [reporter] --timeout [timeout]")['default'](
     {types: 'unit,functional', reporter: 'spec', timeout: 6000})