DomStorageBrowserTest sanity check

content/test/data/dom_storage/sanity_check.js

+// Copyright (c) 2012 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.
+
+function startTestSoon() {
+  window.setTimeout(test, 0);
+}
+
+function test() {
+  try {
+    debug('Checking window.localStorage');
+    sanityCheck(window.localStorage);
+    debug('Checking window.sessionStorage');
+    sanityCheck(window.sessionStorage);
+    done();
+  } catch(e) {
+    fail(e);
+  }
+}
+
+function sanityCheck(storage) {
+  storage.clear();
+
+  checkEqual(0, storage.length,
+             "storage.length != 0 at start");
+  checkEqual(null, storage.getItem("foo"),
+             "getItem('foo') != null prior to addition");
+  checkEqual(null, storage.key(0),
+             "key(0) != null prior to addition");
+
+  storage.setItem("foo", "bar");
+
+  checkEqual(1, storage.length,
+             "storage.length != 1 after addition");
+  checkEqual("bar", storage.getItem("foo"),
+             "getItem('foo') != 'bar' after addition");
+  checkEqual("foo", storage.key(0),
+             "key(0) != 'foo' after addition");
+
+  storage.removeItem("foo");
+
+  checkEqual(null, storage.getItem("foo"),
+             "getItem('foo') != null after removal");
+
+  storage["foo"] = "baz";
+  storage["name"] = "value";
+
+  checkEqual(2, storage.length,
+             "storage.length != 2 after 2 additions");
+  checkEqual("baz", storage["foo"],
+             "storage['foo'] != 'baz' after addition");
+  checkEqual("value", storage["name"],
+             "storage['name'] != 'value' after addition");
+
+  storage.clear();
+
+  checkEqual(0, storage.length,
+             "storage.length != 0 after clear");
+
+  try {
+    storage.setItem("tooLarge", makeLargeString((5 * 1024 * 1024) + 1));
+    throw "failed to throw execption for very large value";
+  } catch(ex) {
+    checkEqual(ex.code, 22,
+               "ex.code != 22 for attempt to store a very large value");
+  }
+}
+
+function checkEqual(lhs, rhs, errorMessage) {
+  if (lhs !== rhs)
+    throw errorMessage;
+}
+
+function makeLargeString(minimumSize) {
+  return Array(minimumSize).join("X");
+}