[fsp] Add FileStreamReader for the reading operation.

chrome/test/data/extensions/api_test/file_system_provider/read_file/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 {number}
+ */
+var fileSystemId = 0;
+
+/**
+ * @type {?DOMFileSystem}
+ */
+var fileSystem = null;
+
+/**
+ * Map of opened files, from a <code>openRequestId</code> to <code>filePath
+ * </code>.
+ * @type {Object.<number, string>}
+ */
+var openedFiles = {};
+
+/**
+ * @type {Object}
+ * @const
+ */
+var TESTING_ROOT = Object.freeze({
+  isDirectory: true,
+  name: '',
+  size: 0,
+  modificationTime: new Date(2014, 4, 28, 10, 39, 15)
+});
+
+/**
+ * Testing contents for files.
+ * @type {string}
+ * @const
+ */
+var TESTING_TEXT = 'I have a basket full of fruits.';
+
+/**
+ * Metadata of a healthy file used to read contents from.
+ * @type {Object}
+ * @const
+ */
+var TESTING_TIRAMISU_FILE = Object.freeze({
+  isDirectory: false,
+  name: 'tiramisu.txt',
+  size: TESTING_TEXT.length,
+  modificationTime: new Date(2014, 1, 25, 7, 36, 12)
+});
+
+/**
+ * Metadata of a broken file used to read contents from.
+ * @type {Object}
+ * @const
+ */
+var TESTING_BROKEN_TIRAMISU_FILE = Object.freeze({
+  isDirectory: false,
+  name: 'broken-tiramisu.txt',
+  size: TESTING_TEXT.length,
+  modificationTime: new Date(2014, 1, 25, 7, 36, 12)
+});
+
+/**
+ * Returns entries in the requested directory.
+ *
+ * @param {number} inFileSystemId ID of the file system.
+ * @param {string} directoryPath Path of the directory.
+ * @param {function(Array.<Object>, boolean)} onSuccess Success callback with
+ *     a list of entries. May be called multiple times.
+ * @param {function(string)} onError Error callback with an error code.
+ */
+function onReadDirectoryRequested(
+    inFileSystemId, directoryPath, onSuccess, onError) {
+  if (inFileSystemId != fileSystemId) {
+    onError('SECURITY_ERROR');  // enum ProviderError.
+    return;
+  }
+
+  if (directoryPath != '/' + TESTING_HELLO_DIR.name) {
+    onError('NOT_FOUND');  // enum ProviderError.
+    return;
+  }
+
+  onSuccess([TESTING_TIRAMISU_FILE], true /* has_next */);
+  onSuccess([TESTING_BROKEN_TIRAMISU_FILE], false /* has_next */);

[hirono, 2014/05/16 04:06:47]

The comment is wrong?

[mtomasz, 2014/05/16 06:19:08]

Which comment? has_next in the comment is a name of the argument.

[hirono, 2014/05/16 06:23:41]

Ah, I misunderstood as it is the meaning of value.

+}
+
+/**
+ * Returns metadata for the requested entry.
+ *
+ * To successfully acquire a DirectoryEntry, or even a DOMFileSystem, this event
+ * must be implemented and return correct values.
+ *
+ * @param {number} inFileSystemId ID of the file system.
+ * @param {string} entryPath Path of the requested entry.
+ * @param {function(Object)} onSuccess Success callback with metadata passed
+ *     an argument.
+ * @param {function(string)} onError Error callback with an error code.
+ */
+function onGetMetadataRequested(
+    inFileSystemId, entryPath, onSuccess, onError) {
+  if (inFileSystemId != fileSystemId) {
+    onError('SECURITY_ERROR');  // enum ProviderError.
+    return;
+  }
+
+  if (entryPath == '/') {
+    onSuccess(TESTING_ROOT);
+    return;
+  }
+
+  if (entryPath == '/' + TESTING_TIRAMISU_FILE.name) {
+    onSuccess(TESTING_TIRAMISU_FILE);
+    return;
+  }
+
+  if (entryPath == '/' + TESTING_BROKEN_TIRAMISU_FILE.name) {
+    onSuccess(TESTING_BROKEN_TIRAMISU_FILE);
+    return;
+  }
+
+  onError('NOT_FOUND');  // enum ProviderError.
+}
+
+/**
+ * Requests opening a file at <code>filePath</code>. Further file operations
+ * will be associated with the <code>requestId</code>
+ *
+ * @param {number} inFileSystemId ID of the file system.
+ * @param {number} requestId ID of the opening request. Used later for reading.
+ * @param {string} filePath Path of the file to be opened.
+ * @param {string} mode Mode, either reading or writing.
+ * @param {boolean} create True to create if doesn't exist.
+ * @param {function()} onSuccess Success callback.
+ * @param {function(string)} onError Error callback.
+ */
+function onOpenFileRequested(
+    inFileSystemId, requestId, filePath, mode, create, onSuccess, onError) {
+  if (inFileSystemId != fileSystemId || mode != 'READ' || create) {
+    onError('SECURITY_ERROR');  // enum ProviderError.
+    return;
+  }
+
+  if (filePath == '/' + TESTING_TIRAMISU_FILE.name ||
+      filePath == '/' + TESTING_BROKEN_TIRAMISU_FILE.name) {
+    openedFiles[requestId] = filePath;
+    onSuccess();
+  } else {
+    onError('NOT_FOUND');  // enum ProviderError.
+  }
+}
+
+/**
+ * Requests closing a file previously opened with <code>openRequestId</code>.
+ *
+ * @param {number} inFileSystemId ID of the file system.
+ * @param {number} openRequestId ID of the request used to open the file.
+ * @param {function()} onSuccess Success callback.
+ * @param {function(string)} onError Error callback.
+ */
+function onCloseFileRequested(
+    inFileSystemId, openRequestId, onSuccess, onError) {
+  if (inFileSystemId != fileSystemId || !openedFiles[openRequestId]) {
+    onError('SECURITY_ERROR');  // enum ProviderError.
+    return;
+  }
+
+  delete openedFiles[requestId];
+  onSuccess();
+}
+
+/**
+ * Requests reading contents of a file, previously opened with <code>
+ * openRequestId</code>.
+ *
+ * @param {number} inFileSystemId ID of the file system.
+ * @param {number} openRequestId ID of the request used to open the file.
+ * @param {number} offset Offset of the file.
+ * @param {number} length Number of bytes to read.
+ * @param {function(string, boolean)} onSuccess Success callback with a chunk
+ *     of data, and information if more data will be provided later.
+ * @param {function(string)} onError Error callback.
+ */
+function onReadFileRequested(
+    inFileSystemId, openRequestId, offset, length, onSuccess, onError) {
+  var filePath = openedFiles[openRequestId];
+  if (inFileSystemId != fileSystemId || !filePath) {
+    onError('SECURITY_ERROR');  // enum ProviderError.
+    return;
+  }
+
+  if (filePath == '/' + TESTING_TIRAMISU_FILE.name) {
+    var textToSend = TESTING_TEXT.substr(offset, length);
+    var textToSendInChunks = textToSend.split('(?= )');

[hirono, 2014/05/16 04:06:47]

/(?= )/
This one?

[mtomasz, 2014/05/16 06:19:08]

Very good catch. It revealed a bug in the code. Done. Fixed.

+
+    textToSendInChunks.forEach(function(item, index) {
+      onSuccess(item, index < textToSendInChunks.length - 1 /* has_next */);
+    });
+    return;
+  }
+
+  if (filePath == '/' + TESTING_BROKEN_TIRAMISU_FILE.name) {
+    onError('ACCESS_DENIED');  // enum ProviderError.
+    return;
+  }
+
+  onError('INVALID_OPERATION');  // 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('chocolate.zip', function(id) {
+    fileSystemId = id;
+    chrome.fileSystemProvider.onReadDirectoryRequested.addListener(
+        onReadDirectoryRequested);
+    chrome.fileSystemProvider.onGetMetadataRequested.addListener(
+        onGetMetadataRequested);
+    chrome.fileSystemProvider.onOpenFileRequested.addListener(
+        onOpenFileRequested);
+    chrome.fileSystemProvider.onReadFileRequested.addListener(
+        onReadFileRequested);
+    var volumeId =
+        'provided:' + chrome.runtime.id + '-' + fileSystemId + '-user';
+
+    chrome.fileBrowserPrivate.requestFileSystem(
+        volumeId,
+        function(inFileSystem) {
+          chrome.test.assertTrue(!!inFileSystem);
+
+          fileSystem = inFileSystem;
+          callback();
+        });
+  }, function() {
+    chrome.test.fail();
+  });
+}
+
+/**
+ * Runs all of the test cases, one by one.
+ */
+function runTests() {
+  chrome.test.runTests([
+    // Read contents of the /tiramisu.txt file. This file exists, so it should
+    // succeed.
+    function readFileSuccess() {
+      var onTestSuccess = chrome.test.callbackPass(function() {});

[hirono, 2014/05/16 04:06:47]

I just noticed we don't need "function() {}".
chrome.test.callbackPass() returns a function that we want.

[mtomasz, 2014/05/16 06:19:08]

Done.

+      fileSystem.root.getFile(
+          TESTING_TIRAMISU_FILE.name,
+          {create: false},
+          function(fileEntry) {
+            fileEntry.file(function(file) {
+              var fileReader = new FileReader();
+              fileReader.onload = function(e) {
+                var text = fileReader.result;
+                chrome.test.assertEq(TESTING_TEXT, text);
+                onTestSuccess();
+              };
+              fileReader.onerror = function(e) {
+                chrome.test.fail(fileReader.error.name);
+              };
+              fileReader.readAsText(file);
+            },
+            function(error) {
+              chrome.test.fail(error.name);
+            });
+          },
+          function(error) {
+            chrome.test.fail(error.name);
+          });
+    },
+    // Read contents of a file file, but with an error on the way. This should
+    // result in an error.
+    function readEntriesError() {
+      var onTestSuccess = chrome.test.callbackPass(function() {});
+      fileSystem.root.getFile(
+          TESTING_BROKEN_TIRAMISU_FILE.name,
+          {create: false},
+          function(fileEntry) {
+            fileEntry.file(function(file) {
+              var fileReader = new FileReader();
+              fileReader.onload = function(e) {
+                chrome.test.fail();
+              };
+              fileReader.onerror = function(e) {
+                chrome.test.assertEq('NotReadableError', fileReader.error.name);
+                onTestSuccess();
+              };
+              fileReader.readAsText(file);
+            },
+            function(error) {
+              chrome.test.fail();
+            });
+          },
+          function(error) {
+            chrome.test.fail(error.name);
+          });
+    }
+  ]);
+}
+
+// Setup and run all of the test cases.
+setUp(runTests);