[fsp] Simplify browser tests by extracting the common code.

chrome/test/data/extensions/api_test/file_system_provider/get_metadata/test.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.
 
 'use strict';
 
 /**
- * @type {DOMFileSystem}
- */
-var fileSystem = null;
-
-/**
- * @type {string}
- * @const
- */
-var FILE_SYSTEM_ID = 'vanilla';
-
-/**
  * @type {Object}
  * @const
  */
 var TESTING_ROOT = Object.freeze({
   isDirectory: true,
   name: '',
   size: 0,
   modificationTime: new Date(2013, 3, 27, 9, 38, 14)
 });
 
@@ skipping 13 matching lines @@
  * @const
  */
 var TESTING_WRONG_TIME_FILE = Object.freeze({
   isDirectory: false,
   name: 'invalid-time.txt',
   size: 4096,
   modificationTime: new Date('Invalid date.')
 });
 
 /**
- * Gets volume information for the provided file system.
- *
- * @param {string} fileSystemId Id of the provided file system.
- * @param {function(Object)} callback Callback to be called on result, with the
- *     volume information object in case of success, or null if not found.
- */
-function getVolumeInfo(fileSystemId, callback) {
-  chrome.fileBrowserPrivate.getVolumeMetadataList(function(volumeList) {
-    for (var i = 0; i < volumeList.length; i++) {
-      if (volumeList[i].extensionId == chrome.runtime.id &&
-          volumeList[i].fileSystemId == fileSystemId) {
-        callback(volumeList[i]);
-        return;
-      }
-    }
-    callback(null);
-  });
-}
-
-/**
  * Returns metadata for a requested entry.
  *
  * @param {GetMetadataRequestedOptions} options Options.
  * @param {function(Object)} onSuccess Success callback with metadata passed
  *     an argument.
  * @param {function(string)} onError Error callback with an error code.
  */
 function onGetMetadataRequested(options, onSuccess, onError) {
-  if (options.fileSystemId != FILE_SYSTEM_ID) {
+  if (options.fileSystemId != test_util.FILE_SYSTEM_ID) {
     onError('SECURITY');  // enum ProviderError.
     return;
   }
 
   if (options.entryPath == '/') {
     onSuccess(TESTING_ROOT);
     return;
   }
 
   if (options.entryPath == '/' + TESTING_FILE.name) {
     onSuccess(TESTING_FILE);
     return;
   }
 
   if (options.entryPath == '/' + TESTING_WRONG_TIME_FILE.name) {
     onSuccess(TESTING_WRONG_TIME_FILE);
     return;
   }
 
   onError('NOT_FOUND');  // enum ProviderError.
 }
 
 /**
  * Sets up the tests. Called once per all test cases. In case of a failure,
  * the callback is not called.
  *
  * @param {function()} callback Success callback.
  */
 function setUp(callback) {
-  chrome.fileSystemProvider.mount(
-      {fileSystemId: FILE_SYSTEM_ID, displayName: 'chocolate.zip'},
-      function() {
-        chrome.fileSystemProvider.onGetMetadataRequested.addListener(
-            onGetMetadataRequested);
-
-        getVolumeInfo(FILE_SYSTEM_ID, function(volumeInfo) {
-          chrome.test.assertTrue(!!volumeInfo);
-          chrome.fileBrowserPrivate.requestFileSystem(
-              volumeInfo.volumeId,
-              function(inFileSystem) {
-                chrome.test.assertTrue(!!inFileSystem);
-
-                fileSystem = inFileSystem;
-                callback();
-              });
-        });
-      },
-      function() {
-        chrome.test.fail();
-      });
+  chrome.fileSystemProvider.onGetMetadataRequested.addListener(
+      onGetMetadataRequested);
+  test_util.mountFileSystem(callback);
 }
 
 /**
  * Runs all of the test cases, one by one.
  */
 function runTests() {
   chrome.test.runTests([
     // Read metadata of the root.
     function getFileMetadataSuccess() {
       var onSuccess = chrome.test.callbackPass();
-      fileSystem.root.getMetadata(
+      test_util.fileSystem.root.getMetadata(
         function(metadata) {
           chrome.test.assertEq(TESTING_ROOT.size, metadata.size);
           chrome.test.assertEq(
               TESTING_ROOT.modificationTime.toString(),
               metadata.modificationTime.toString());
           onSuccess();
         }, function(error) {
           chrome.test.fail(error.name);
         });
     },
     // Read metadata of an existing testing file.
     function getFileMetadataSuccess() {
       var onSuccess = chrome.test.callbackPass();
-      fileSystem.root.getFile(
+      test_util.fileSystem.root.getFile(
           TESTING_FILE.name,
           {create: false},
           function(fileEntry) {
             chrome.test.assertEq(TESTING_FILE.name, fileEntry.name);
             chrome.test.assertEq(
                 TESTING_FILE.isDirectory, fileEntry.isDirectory);
             fileEntry.getMetadata(function(metadata) {
               chrome.test.assertEq(TESTING_FILE.size, metadata.size);
               chrome.test.assertEq(
                   TESTING_FILE.modificationTime.toString(),
                   metadata.modificationTime.toString());
               onSuccess();
             }, function(error) {
               chrome.test.fail(error.name);
             });
           },
           function(error) {
             chrome.test.fail(error.name);
           });
     },
     // Read metadata of an existing testing file, which however has an invalid
     // modification time. It should not cause an error, but an invalid date
     // should be passed to fileapi instead. The reason is, that there is no
     // easy way to verify an incorrect modification time at early stage.
     function getFileMetadataWrongTimeSuccess() {
       var onSuccess = chrome.test.callbackPass();
-      fileSystem.root.getFile(
+      test_util.fileSystem.root.getFile(
           TESTING_WRONG_TIME_FILE.name,
           {create: false},
           function(fileEntry) {
             chrome.test.assertEq(TESTING_WRONG_TIME_FILE.name, fileEntry.name);
             fileEntry.getMetadata(function(metadata) {
               chrome.test.assertTrue(
                   Number.isNaN(metadata.modificationTime.getTime()));
               onSuccess();
             }, function(error) {
               chrome.test.fail(error.name);
             });
           }, function(error) {
             chrome.test.fail(error.name);
           });
     },
     // Read metadata of a directory which does not exist, what should return an
     // error. DirectoryEntry.getDirectory() causes fetching metadata.
     function getFileMetadataNotFound() {
       var onSuccess = chrome.test.callbackPass();
-      fileSystem.root.getDirectory(
+      test_util.fileSystem.root.getDirectory(
           'cranberries',
           {create: false},
           function(dirEntry) {
             chrome.test.fail();
           },
           function(error) {
             chrome.test.assertEq('NotFoundError', error.name);
             onSuccess();
           });
     },
     // Read metadata of a file using getDirectory(). An error should be returned
     // because of type mismatching. DirectoryEntry.getDirectory() causes
     // fetching metadata.
     function getFileMetadataWrongType() {
       var onSuccess = chrome.test.callbackPass();
-      fileSystem.root.getDirectory(
+      test_util.fileSystem.root.getDirectory(
           TESTING_FILE.name,
           {create: false},
           function(fileEntry) {
             chrome.test.fail();
           },
           function(error) {
             chrome.test.assertEq('TypeMismatchError', error.name);
             onSuccess();
           });
     }
   ]);
 }
 
 // Setup and run all of the test cases.
 setUp(runTests);