Initial ServiceWorker CacheStorage API polyfill.

Source/modules/serviceworkers/polyfills/cacheStoragePolyfill.js

+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// A simple, incomplete implementation of the CacheStorage API, intended to facilitate
+// end to end serviceworker testing.
+
+// See https://slightlyoff.github.io/ServiceWorker/spec/service_worker/index.html#cache-storage
+
+(function(global) {
+    var CacheStorage = function() {
+        this.cachesByName = {};
+    };
+
+    CacheStorage.prototype.get = function(key) {
+        if (this.cachesByName.hasOwnProperty(key)) {
+            return Promise.resolve(this.cachesByName[key]);
+        }
+        return Promise.reject('not found');
+    };
+
+    CacheStorage.prototype.has = function(key) {
+        return Promise.resolve(this.cachesByName.hasOwnProperty(key));
+    };
+
+    // FIXME: Engage standardization on removing this method from the spec.
+    CacheStorage.prototype.set = Promise.reject.bind(Promise, 'CacheStorage.prototype.set() not implemented.');
+
+    // FIXME: Engage standardization on adding this method to the spec.
+    CacheStorage.prototype.create = function(key) {
+        this.cachesByName[key] = new Cache();
+
+        return Promise.resolve();
+    };
+
+    // FIXME: Engage standarization on adding this method to the spec.
+    CacheStorage.prototype.rename = function(fromKey, toKey) {
+        if (!this.cachesByName.hasOwnProperty(fromKey)) {
+            return Promise.reject('not found');
+        }
+        this.cachesByName[toKey] = this.cachesByName[fromKey];
+        delete this.cachesByName[fromKey];
+
+        return Promise.resolve();
+    };
+
+    CacheStorage.prototype.clear = function() {
+        this.cachesByName = {};
+
+        return Promise.resolve();
+    };
+
+    CacheStorage.prototype.delete = function(key) {
+        delete this.cachesByName[key];
+
+        return Promise.resolve();
+    };
+
+    CacheStorage.prototype.forEach = function(callback, thisArg) {
+        Object.keys(this.cachesByName).map(function(key) {
+            thisArg.callback(this.cachesByName[key], key, this);
+        });
+        return Promise.resolve();
+    };
+
+    // FIXME: Implement this.
+    CacheStorage.prototype.entries = Promise.reject.bind(Promise, 'CacheStorage.prototype.entries() not implemented.');
+
+    CacheStorage.prototype.keys = function() {
+        return Promise.resolve(Object.keys(this.cachesByName));
+    };
+
+    CacheStorage.prototype.values = function() {
+        return Promise.resolve(Object.keys(this.cachesByName).map(function(key) {
+            return this.cachesByName[key];
+        }));
+    };
+
+    CacheStorage.prototype.size = function() {
+        return Promise.resolve(Object.keys(this.cachesByName).length);
+    };
+
+    // FIXME: Figure out what should be done with undefined or poorly defined |cacheName| values.
+    CacheStorage.prototype.match = function(url, cacheName) {
+        return this.get(cacheName).then(function(cache) {
+            return cache.match(url);
+        });
+    };
+
+    global.caches = global.caches || new CacheStorage();
+}(self));  // window or worker global scope.