The Tor Browser: netwerk/test/unit/test_backgroundfilesaver.js@ca08bd8f51b2 (annotated)

netwerk/test/unit/test_backgroundfilesaver.js@ca08bd8f51b2 (annotated)

netwerk/test/unit/test_backgroundfilesaver.js

Wed, 31 Dec 2014 06:55:46 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Wed, 31 Dec 2014 06:55:46 +0100
changeset 1: ca08bd8f51b2
permissions: -rw-r--r--

Added tag TORBROWSER_REPLICA for changeset 6474c204b198

 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
 /* vim: set ts=2 et sw=2 tw=80: */
 /* Any copyright is dedicated to the Public Domain.
  * http://creativecommons.org/publicdomain/zero/1.0/ */
 /**
  * This file tests components that implement nsIBackgroundFileSaver.
  */
 ////////////////////////////////////////////////////////////////////////////////
 //// Globals
 Cu.import("resource://gre/modules/XPCOMUtils.jsm");
 XPCOMUtils.defineLazyModuleGetter(this, "FileUtils",
                                   "resource://gre/modules/FileUtils.jsm");
 XPCOMUtils.defineLazyModuleGetter(this, "NetUtil",
                                   "resource://gre/modules/NetUtil.jsm");
 XPCOMUtils.defineLazyModuleGetter(this, "Promise",
                                   "resource://gre/modules/Promise.jsm");
 XPCOMUtils.defineLazyModuleGetter(this, "Task",
                                   "resource://gre/modules/Task.jsm");
 const BackgroundFileSaverOutputStream = Components.Constructor(
       "@mozilla.org/network/background-file-saver;1?mode=outputstream",
       "nsIBackgroundFileSaver");
 const BackgroundFileSaverStreamListener = Components.Constructor(
       "@mozilla.org/network/background-file-saver;1?mode=streamlistener",
       "nsIBackgroundFileSaver");
 const StringInputStream = Components.Constructor(
       "@mozilla.org/io/string-input-stream;1",
       "nsIStringInputStream",
       "setData");
 const REQUEST_SUSPEND_AT = 1024 * 1024 * 4;
 const TEST_DATA_SHORT = "This test string is written to the file.";
 const TEST_FILE_NAME_1 = "test-backgroundfilesaver-1.txt";
 const TEST_FILE_NAME_2 = "test-backgroundfilesaver-2.txt";
 const TEST_FILE_NAME_3 = "test-backgroundfilesaver-3.txt";
 // A map of test data length to the expected SHA-256 hashes
 const EXPECTED_HASHES = {
   // No data
 : "e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855",
   // TEST_DATA_SHORT
 : "f37176b690e8744ee990a206c086cba54d1502aa2456c3b0c84ef6345d72a192",
   // TEST_DATA_SHORT + TEST_DATA_SHORT
 : "780c0e91f50bb7ec922cc11e16859e6d5df283c0d9470f61772e3d79f41eeb58",
   // TEST_DATA_LONG
   8388608 : "e3611a47714c42bdf326acfb2eb6ed9fa4cca65cb7d7be55217770a5bf5e7ff0",
   // TEST_DATA_LONG + TEST_DATA_LONG
   16777216 : "03a0db69a30140f307587ee746a539247c181bafd85b85c8516a3533c7d9ea1d"
 };
 const gTextDecoder = new TextDecoder();
 // Generate a long string of data in a moderately fast way.
 const TEST_256_CHARS = new Array(257).join("-");
 const DESIRED_LENGTH = REQUEST_SUSPEND_AT * 2;
 const TEST_DATA_LONG = new Array(1 + DESIRED_LENGTH / 256).join(TEST_256_CHARS);
 do_check_eq(TEST_DATA_LONG.length, DESIRED_LENGTH);
 /**
  * Returns a reference to a temporary file.  If the file is then created, it
  * will be removed when tests in this file finish.
  */
 function getTempFile(aLeafName) {
   let file = FileUtils.getFile("TmpD", [aLeafName]);
   do_register_cleanup(function GTF_cleanup() {
     if (file.exists()) {
       file.remove(false);
     }
   });
   return file;
 }
 /**
  * Helper function for converting a binary blob to its hex equivalent.
  *
  * @param str
  *        String possibly containing non-printable chars.
  * @return A hex-encoded string.
  */
 function toHex(str) {
   var hex = '';
   for (var i = 0; i < str.length; i++) {
     hex += ('0' + str.charCodeAt(i).toString(16)).slice(-2);
   }
   return hex;
 }
 /**
  * Ensures that the given file contents are equal to the given string.
  *
  * @param aFile
  *        nsIFile whose contents should be verified.
  * @param aExpectedContents
  *        String containing the octets that are expected in the file.
  *
  * @return {Promise}
  * @resolves When the operation completes.
  * @rejects Never.
  */
 function promiseVerifyContents(aFile, aExpectedContents) {
   let deferred = Promise.defer();
   NetUtil.asyncFetch(aFile, function(aInputStream, aStatus) {
     do_check_true(Components.isSuccessCode(aStatus));
     let contents = NetUtil.readInputStreamToString(aInputStream,
                                                    aInputStream.available());
     if (contents.length <= TEST_DATA_SHORT.length * 2) {
       do_check_eq(contents, aExpectedContents);
     } else {
       // Do not print the entire content string to the test log.
       do_check_eq(contents.length, aExpectedContents.length);
       do_check_true(contents == aExpectedContents);
     }
     deferred.resolve();
   });
   return deferred.promise;
 }
 /**
  * Waits for the given saver object to complete.
  *
  * @param aSaver
  *        The saver, with the output stream or a stream listener implementation.
  * @param aOnTargetChangeFn
  *        Optional callback invoked with the target file name when it changes.
  *
  * @return {Promise}
  * @resolves When onSaveComplete is called with a success code.
  * @rejects With an exception, if onSaveComplete is called with a failure code.
  */
 function promiseSaverComplete(aSaver, aOnTargetChangeFn) {
   let deferred = Promise.defer();
   aSaver.observer = {
     onTargetChange: function BFSO_onSaveComplete(aSaver, aTarget)
     {
       if (aOnTargetChangeFn) {
         aOnTargetChangeFn(aTarget);
       }
     },
     onSaveComplete: function BFSO_onSaveComplete(aSaver, aStatus)
     {
       if (Components.isSuccessCode(aStatus)) {
         deferred.resolve();
       } else {
         deferred.reject(new Components.Exception("Saver failed.", aStatus));
       }
     },
   };
   return deferred.promise;
 }
 /**
  * Feeds a string to a BackgroundFileSaverOutputStream.
  *
  * @param aSourceString
  *        The source data to copy.
  * @param aSaverOutputStream
  *        The BackgroundFileSaverOutputStream to feed.
  * @param aCloseWhenDone
  *        If true, the output stream will be closed when the copy finishes.
  *
  * @return {Promise}
  * @resolves When the copy completes with a success code.
  * @rejects With an exception, if the copy fails.
  */
 function promiseCopyToSaver(aSourceString, aSaverOutputStream, aCloseWhenDone) {
   let deferred = Promise.defer();
   let inputStream = new StringInputStream(aSourceString, aSourceString.length);
   let copier = Cc["@mozilla.org/network/async-stream-copier;1"]
                .createInstance(Ci.nsIAsyncStreamCopier);
   copier.init(inputStream, aSaverOutputStream, null, false, true, 0x8000, true,
               aCloseWhenDone);
   copier.asyncCopy({
     onStartRequest: function () { },
     onStopRequest: function (aRequest, aContext, aStatusCode)
     {
       if (Components.isSuccessCode(aStatusCode)) {
         deferred.resolve();
       } else {
         deferred.reject(new Components.Exception(aResult));
       }
     },
   }, null);
   return deferred.promise;
 }
 /**
  * Feeds a string to a BackgroundFileSaverStreamListener.
  *
  * @param aSourceString
  *        The source data to copy.
  * @param aSaverStreamListener
  *        The BackgroundFileSaverStreamListener to feed.
  * @param aCloseWhenDone
  *        If true, the output stream will be closed when the copy finishes.
  *
  * @return {Promise}
  * @resolves When the operation completes with a success code.
  * @rejects With an exception, if the operation fails.
  */
 function promisePumpToSaver(aSourceString, aSaverStreamListener,
                             aCloseWhenDone) {
   let deferred = Promise.defer();
   aSaverStreamListener.QueryInterface(Ci.nsIStreamListener);
   let inputStream = new StringInputStream(aSourceString, aSourceString.length);
   let pump = Cc["@mozilla.org/network/input-stream-pump;1"]
              .createInstance(Ci.nsIInputStreamPump);
   pump.init(inputStream, -1, -1, 0, 0, true);
   pump.asyncRead({
     onStartRequest: function PPTS_onStartRequest(aRequest, aContext)
     {
       aSaverStreamListener.onStartRequest(aRequest, aContext);
     },
     onStopRequest: function PPTS_onStopRequest(aRequest, aContext, aStatusCode)
     {
       aSaverStreamListener.onStopRequest(aRequest, aContext, aStatusCode);
       if (Components.isSuccessCode(aStatusCode)) {
         deferred.resolve();
       } else {
         deferred.reject(new Components.Exception(aResult));
       }
     },
     onDataAvailable: function PPTS_onDataAvailable(aRequest, aContext,
                                                    aInputStream, aOffset,
                                                    aCount)
     {
       aSaverStreamListener.onDataAvailable(aRequest, aContext, aInputStream,
                                            aOffset, aCount);
     },
   }, null);
   return deferred.promise;
 }
 let gStillRunning = true;
 ////////////////////////////////////////////////////////////////////////////////
 //// Tests
 function run_test()
 {
   run_next_test();
 }
 add_task(function test_setup()
 {
   // Wait 10 minutes, that is half of the external xpcshell timeout.
   do_timeout(10 * 60 * 1000, function() {
     if (gStillRunning) {
       do_throw("Test timed out.");
     }
   })
 });
 add_task(function test_normal()
 {
   // This test demonstrates the most basic use case.
   let destFile = getTempFile(TEST_FILE_NAME_1);
   // Create the object implementing the output stream.
   let saver = new BackgroundFileSaverOutputStream();
   // Set up callbacks for completion and target file name change.
   let receivedOnTargetChange = false;
   function onTargetChange(aTarget) {
     do_check_true(destFile.equals(aTarget));
     receivedOnTargetChange = true;
   }
   let completionPromise = promiseSaverComplete(saver, onTargetChange);
   // Set the target file.
   saver.setTarget(destFile, false);
   // Write some data and close the output stream.
   yield promiseCopyToSaver(TEST_DATA_SHORT, saver, true);
   // Indicate that we are ready to finish, and wait for a successful callback.
   saver.finish(Cr.NS_OK);
   yield completionPromise;
   // Only after we receive the completion notification, we can also be sure that
   // we've received the target file name change notification before it.
   do_check_true(receivedOnTargetChange);
   // Clean up.
   destFile.remove(false);
 });
 add_task(function test_combinations()
 {
   let initialFile = getTempFile(TEST_FILE_NAME_1);
   let renamedFile = getTempFile(TEST_FILE_NAME_2);
   // Keep track of the current file.
   let currentFile = null;
   function onTargetChange(aTarget) {
     currentFile = null;
     do_print("Target file changed to: " + aTarget.leafName);
     currentFile = aTarget;
   }
   // Tests various combinations of events and behaviors for both the stream
   // listener and the output stream implementations.
   for (let testFlags = 0; testFlags < 32; testFlags++) {
     let keepPartialOnFailure = !!(testFlags & 1);
     let renameAtSomePoint = !!(testFlags & 2);
     let cancelAtSomePoint = !!(testFlags & 4);
     let useStreamListener = !!(testFlags & 8);
     let useLongData = !!(testFlags & 16);
     let startTime = Date.now();
     do_print("Starting keepPartialOnFailure = " + keepPartialOnFailure +
                     ", renameAtSomePoint = " + renameAtSomePoint +
                     ", cancelAtSomePoint = " + cancelAtSomePoint +
                     ", useStreamListener = " + useStreamListener +
                     ", useLongData = " + useLongData);
     // Create the object and register the observers.
     currentFile = null;
     let saver = useStreamListener
                 ? new BackgroundFileSaverStreamListener()
                 : new BackgroundFileSaverOutputStream();
     saver.enableSha256();
     let completionPromise = promiseSaverComplete(saver, onTargetChange);
     // Start feeding the first chunk of data to the saver.  In case we are using
     // the stream listener, we only write one chunk.
     let testData = useLongData ? TEST_DATA_LONG : TEST_DATA_SHORT;
     let feedPromise = useStreamListener
                       ? promisePumpToSaver(testData + testData, saver)
                       : promiseCopyToSaver(testData, saver, false);
     // Set a target output file.
     saver.setTarget(initialFile, keepPartialOnFailure);
     // Wait for the first chunk of data to be copied.
     yield feedPromise;
     if (renameAtSomePoint) {
       saver.setTarget(renamedFile, keepPartialOnFailure);
     }
     if (cancelAtSomePoint) {
       saver.finish(Cr.NS_ERROR_FAILURE);
     }
     // Feed the second chunk of data to the saver.
     if (!useStreamListener) {
       yield promiseCopyToSaver(testData, saver, true);
     }
     // Wait for completion, and ensure we succeeded or failed as expected.
     if (!cancelAtSomePoint) {
       saver.finish(Cr.NS_OK);
     }
     try {
       yield completionPromise;
       if (cancelAtSomePoint) {
         do_throw("Failure expected.");
       }
     } catch (ex if cancelAtSomePoint && ex.result == Cr.NS_ERROR_FAILURE) { }
     if (!cancelAtSomePoint) {
       // In this case, the file must exist.
       do_check_true(currentFile.exists());
       let expectedContents = testData + testData;
       yield promiseVerifyContents(currentFile, expectedContents);
       do_check_eq(EXPECTED_HASHES[expectedContents.length],
                   toHex(saver.sha256Hash));
       currentFile.remove(false);
       // If the target was really renamed, the old file should not exist.
       if (renamedFile.equals(currentFile)) {
         do_check_false(initialFile.exists());
       }
     } else if (!keepPartialOnFailure) {
       // In this case, the file must not exist.
       do_check_false(initialFile.exists());
       do_check_false(renamedFile.exists());
     } else {
       // In this case, the file may or may not exist, because canceling can
       // interrupt the asynchronous operation at any point, even before the file
       // has been created for the first time.
       if (initialFile.exists()) {
         initialFile.remove(false);
       }
       if (renamedFile.exists()) {
         renamedFile.remove(false);
       }
     }
     do_print("Test case completed in " + (Date.now() - startTime) + " ms.");
   }
 });
 add_task(function test_setTarget_after_close_stream()
 {
   // This test checks the case where we close the output stream before we call
   // the setTarget method.  All the data should be buffered and written anyway.
   let destFile = getTempFile(TEST_FILE_NAME_1);
   // Test the case where the file does not already exists first, then the case
   // where the file already exists.
   for (let i = 0; i < 2; i++) {
     let saver = new BackgroundFileSaverOutputStream();
     saver.enableSha256();
     let completionPromise = promiseSaverComplete(saver);
     // Copy some data to the output stream of the file saver.  This data must
     // be shorter than the internal component's pipe buffer for the test to
     // succeed, because otherwise the test would block waiting for the write to
     // complete.
     yield promiseCopyToSaver(TEST_DATA_SHORT, saver, true);
     // Set the target file and wait for the output to finish.
     saver.setTarget(destFile, false);
     saver.finish(Cr.NS_OK);
     yield completionPromise;
     // Verify results.
     yield promiseVerifyContents(destFile, TEST_DATA_SHORT);
     do_check_eq(EXPECTED_HASHES[TEST_DATA_SHORT.length],
                 toHex(saver.sha256Hash));
   }
   // Clean up.
   destFile.remove(false);
 });
 add_task(function test_setTarget_fast()
 {
   // This test checks a fast rename of the target file.
   let destFile1 = getTempFile(TEST_FILE_NAME_1);
   let destFile2 = getTempFile(TEST_FILE_NAME_2);
   let saver = new BackgroundFileSaverOutputStream();
   let completionPromise = promiseSaverComplete(saver);
   // Set the initial name after the stream is closed, then rename immediately.
   yield promiseCopyToSaver(TEST_DATA_SHORT, saver, true);
   saver.setTarget(destFile1, false);
   saver.setTarget(destFile2, false);
   // Wait for all the operations to complete.
   saver.finish(Cr.NS_OK);
   yield completionPromise;
   // Verify results and clean up.
   do_check_false(destFile1.exists());
   yield promiseVerifyContents(destFile2, TEST_DATA_SHORT);
   destFile2.remove(false);
 });
 add_task(function test_setTarget_multiple()
 {
   // This test checks multiple renames of the target file.
   let destFile = getTempFile(TEST_FILE_NAME_1);
   let saver = new BackgroundFileSaverOutputStream();
   let completionPromise = promiseSaverComplete(saver);
   // Rename both before and after the stream is closed.
   saver.setTarget(getTempFile(TEST_FILE_NAME_2), false);
   saver.setTarget(getTempFile(TEST_FILE_NAME_3), false);
   yield promiseCopyToSaver(TEST_DATA_SHORT, saver, true);
   saver.setTarget(getTempFile(TEST_FILE_NAME_2), false);
   saver.setTarget(destFile, false);
   // Wait for all the operations to complete.
   saver.finish(Cr.NS_OK);
   yield completionPromise;
   // Verify results and clean up.
   do_check_false(getTempFile(TEST_FILE_NAME_2).exists());
   do_check_false(getTempFile(TEST_FILE_NAME_3).exists());
   yield promiseVerifyContents(destFile, TEST_DATA_SHORT);
   destFile.remove(false);
 });
 add_task(function test_enableAppend()
 {
   // This test checks append mode with hashing disabled.
   let destFile = getTempFile(TEST_FILE_NAME_1);
   // Test the case where the file does not already exists first, then the case
   // where the file already exists.
   for (let i = 0; i < 2; i++) {
     let saver = new BackgroundFileSaverOutputStream();
     saver.enableAppend();
     let completionPromise = promiseSaverComplete(saver);
     saver.setTarget(destFile, false);
     yield promiseCopyToSaver(TEST_DATA_LONG, saver, true);
     saver.finish(Cr.NS_OK);
     yield completionPromise;
     // Verify results.
     let expectedContents = (i == 0 ? TEST_DATA_LONG
                                    : TEST_DATA_LONG + TEST_DATA_LONG);
     yield promiseVerifyContents(destFile, expectedContents);
   }
   // Clean up.
   destFile.remove(false);
 });
 add_task(function test_enableAppend_setTarget_fast()
 {
   // This test checks a fast rename of the target file in append mode.
   let destFile1 = getTempFile(TEST_FILE_NAME_1);
   let destFile2 = getTempFile(TEST_FILE_NAME_2);
   // Test the case where the file does not already exists first, then the case
   // where the file already exists.
   for (let i = 0; i < 2; i++) {
     let saver = new BackgroundFileSaverOutputStream();
     saver.enableAppend();
     let completionPromise = promiseSaverComplete(saver);
     yield promiseCopyToSaver(TEST_DATA_SHORT, saver, true);
     // The first time, we start appending to the first file and rename to the
     // second file.  The second time, we start appending to the second file,
     // that was created the first time, and rename back to the first file.
     let firstFile = (i == 0) ? destFile1 : destFile2;
     let secondFile = (i == 0) ? destFile2 : destFile1;
     saver.setTarget(firstFile, false);
     saver.setTarget(secondFile, false);
     saver.finish(Cr.NS_OK);
     yield completionPromise;
     // Verify results.
     do_check_false(firstFile.exists());
     let expectedContents = (i == 0 ? TEST_DATA_SHORT
                                    : TEST_DATA_SHORT + TEST_DATA_SHORT);
     yield promiseVerifyContents(secondFile, expectedContents);
   }
   // Clean up.
   destFile1.remove(false);
 });
 add_task(function test_enableAppend_hash()
 {
   // This test checks append mode, also verifying that the computed hash
   // includes the contents of the existing data.
   let destFile = getTempFile(TEST_FILE_NAME_1);
   // Test the case where the file does not already exists first, then the case
   // where the file already exists.
   for (let i = 0; i < 2; i++) {
     let saver = new BackgroundFileSaverOutputStream();
     saver.enableAppend();
     saver.enableSha256();
     let completionPromise = promiseSaverComplete(saver);
     saver.setTarget(destFile, false);
     yield promiseCopyToSaver(TEST_DATA_LONG, saver, true);
     saver.finish(Cr.NS_OK);
     yield completionPromise;
     // Verify results.
     let expectedContents = (i == 0 ? TEST_DATA_LONG
                                    : TEST_DATA_LONG + TEST_DATA_LONG);
     yield promiseVerifyContents(destFile, expectedContents);
     do_check_eq(EXPECTED_HASHES[expectedContents.length],
                 toHex(saver.sha256Hash));
   }
   // Clean up.
   destFile.remove(false);
 });
 add_task(function test_finish_only()
 {
   // This test checks creating the object and doing nothing.
   let destFile = getTempFile(TEST_FILE_NAME_1);
   let saver = new BackgroundFileSaverOutputStream();
   function onTargetChange(aTarget) {
     do_throw("Should not receive the onTargetChange notification.");
   }
   let completionPromise = promiseSaverComplete(saver, onTargetChange);
   saver.finish(Cr.NS_OK);
   yield completionPromise;
 });
 add_task(function test_empty()
 {
   // This test checks we still create an empty file when no data is fed.
   let destFile = getTempFile(TEST_FILE_NAME_1);
   let saver = new BackgroundFileSaverOutputStream();
   let completionPromise = promiseSaverComplete(saver);
   saver.setTarget(destFile, false);
   yield promiseCopyToSaver("", saver, true);
   saver.finish(Cr.NS_OK);
   yield completionPromise;
   // Verify results.
   do_check_true(destFile.exists());
   do_check_eq(destFile.fileSize, 0);
   // Clean up.
   destFile.remove(false);
 });
 add_task(function test_empty_hash()
 {
   // This test checks the hash of an empty file, both in normal and append mode.
   let destFile = getTempFile(TEST_FILE_NAME_1);
   // Test normal mode first, then append mode.
   for (let i = 0; i < 2; i++) {
     let saver = new BackgroundFileSaverOutputStream();
     if (i == 1) {
       saver.enableAppend();
     }
     saver.enableSha256();
     let completionPromise = promiseSaverComplete(saver);
     saver.setTarget(destFile, false);
     yield promiseCopyToSaver("", saver, true);
     saver.finish(Cr.NS_OK);
     yield completionPromise;
     // Verify results.
     do_check_eq(destFile.fileSize, 0);
     do_check_eq(EXPECTED_HASHES[0], toHex(saver.sha256Hash));
   }
   // Clean up.
   destFile.remove(false);
 });
 add_task(function test_invalid_hash()
 {
   let saver = new BackgroundFileSaverStreamListener();
   let completionPromise = promiseSaverComplete(saver);
   // We shouldn't be able to get the hash if hashing hasn't been enabled
   try {
     let hash = saver.sha256Hash;
     do_throw("Shouldn't be able to get hash if hashing not enabled");
   } catch (ex if ex.result == Cr.NS_ERROR_NOT_AVAILABLE) { }
   // Enable hashing, but don't feed any data to saver
   saver.enableSha256();
   let destFile = getTempFile(TEST_FILE_NAME_1);
   saver.setTarget(destFile, false);
   // We don't wait on promiseSaverComplete, so the hash getter can run before
   // or after onSaveComplete is called. However, the expected behavior is the
   // same in both cases since the hash is only valid when the save completes
   // successfully.
   saver.finish(Cr.NS_ERROR_FAILURE);
   try {
     let hash = saver.sha256Hash;
     do_throw("Shouldn't be able to get hash if save did not succeed");
   } catch (ex if ex.result == Cr.NS_ERROR_NOT_AVAILABLE) { }
   // Wait for completion so that the worker thread finishes dealing with the
   // target file. We expect it to fail.
   try {
     yield completionPromise;
     do_throw("completionPromise should throw");
   } catch (ex if ex.result == Cr.NS_ERROR_FAILURE) { }
 });
 add_task(function test_signature()
 {
   // Check that we get a signature if the saver is finished.
   let destFile = getTempFile(TEST_FILE_NAME_1);
   let saver = new BackgroundFileSaverOutputStream();
   let completionPromise = promiseSaverComplete(saver);
   try {
     let signatureInfo = saver.signatureInfo;
     do_throw("Can't get signature if saver is not complete");
   } catch (ex if ex.result == Cr.NS_ERROR_NOT_AVAILABLE) { }
   saver.enableSignatureInfo();
   saver.setTarget(destFile, false);
   yield promiseCopyToSaver(TEST_DATA_SHORT, saver, true);
   saver.finish(Cr.NS_OK);
   yield completionPromise;
   yield promiseVerifyContents(destFile, TEST_DATA_SHORT);
   // signatureInfo is an empty nsIArray
   do_check_eq(0, saver.signatureInfo.length);
   // Clean up.
   destFile.remove(false);
 });
 add_task(function test_signature_not_enabled()
 {
   // Check that we get a signature if the saver is finished on Windows.
   let destFile = getTempFile(TEST_FILE_NAME_1);
   let saver = new BackgroundFileSaverOutputStream();
   let completionPromise = promiseSaverComplete(saver);
   saver.setTarget(destFile, false);
   yield promiseCopyToSaver(TEST_DATA_SHORT, saver, true);
   saver.finish(Cr.NS_OK);
   yield completionPromise;
   try {
     let signatureInfo = saver.signatureInfo;
     do_throw("Can't get signature if not enabled");
   } catch (ex if ex.result == Cr.NS_ERROR_NOT_AVAILABLE) { }
   // Clean up.
   destFile.remove(false);
 });
 add_task(function test_teardown()
 {
   gStillRunning = false;
 });