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 /* Any copyright is dedicated to the Public Domain.

    http://creativecommons.org/publicdomain/zero/1.0/ */

 // This tests are for a sessionstore.js atomic backup.

 // Each test will wait for a write to the Session Store

 // before executing.

 let tmp = {};

 Cu.import("resource://gre/modules/osfile.jsm", tmp);

 Cu.import("resource:///modules/sessionstore/SessionFile.jsm", tmp);

 const {OS, SessionFile} = tmp;

 const PREF_SS_INTERVAL = "browser.sessionstore.interval";

 // Full paths for sessionstore.js and sessionstore.bak.

 const path = OS.Path.join(OS.Constants.Path.profileDir, "sessionstore.js");

 const backupPath = OS.Path.join(OS.Constants.Path.profileDir,

   "sessionstore.bak");

 // A text decoder.

 let gDecoder = new TextDecoder();

 // Global variables that contain sessionstore.js and sessionstore.bak data for

 // comparison between tests.

 let gSSData;

 let gSSBakData;

 add_task(function* testAfterFirstWrite() {

   // Ensure sessionstore.bak is not created. We start with a clean

   // profile so there was nothing to move to sessionstore.bak before

   // initially writing sessionstore.js

   let ssExists = yield OS.File.exists(path);

   let ssBackupExists = yield OS.File.exists(backupPath);

   ok(ssExists, "sessionstore.js should exist.");

   ok(!ssBackupExists, "sessionstore.bak should not have been created, yet");

   // Save sessionstore.js data to compare to the sessionstore.bak data in the

   // next test.

   let array = yield OS.File.read(path);

   gSSData = gDecoder.decode(array);

   // Manually move to the backup since the first write has already happened

   // and a backup would not be triggered again.

   yield OS.File.move(path, backupPath);

   yield forceSaveState();

 });

 add_task(function* testReadBackup() {

   // Ensure sessionstore.bak is finally created.

   let ssExists = yield OS.File.exists(path);

   let ssBackupExists = yield OS.File.exists(backupPath);

   ok(ssExists, "sessionstore.js exists.");

   ok(ssBackupExists, "sessionstore.bak should now be created.");

   // Read sessionstore.bak data.

   let array = yield OS.File.read(backupPath);

   gSSBakData = gDecoder.decode(array);

   // Make sure that the sessionstore.bak is identical to the last

   // sessionstore.js.

   is(gSSBakData, gSSData, "sessionstore.js is backed up correctly.");

   // Read latest sessionstore.js.

   array = yield OS.File.read(path);

   gSSData = gDecoder.decode(array);

   // Read sessionstore.js with SessionFile.read.

   let ssDataRead = yield SessionFile.read();

   is(ssDataRead, gSSData, "SessionFile.read read sessionstore.js correctly.");

   // Remove sessionstore.js to test fallback onto sessionstore.bak.

   yield OS.File.remove(path);

   ssExists = yield OS.File.exists(path);

   ok(!ssExists, "sessionstore.js should be removed now.");

   // Read sessionstore.bak with SessionFile.read.

   ssDataRead = yield SessionFile.read();

   is(ssDataRead, gSSBakData,

     "SessionFile.read read sessionstore.bak correctly.");

   yield forceSaveState();

 });

 add_task(function* testBackupUnchanged() {

   // Ensure sessionstore.bak is backed up only once.

   // Read sessionstore.bak data.

   let array = yield OS.File.read(backupPath);

   let ssBakData = gDecoder.decode(array);

   // Ensure the sessionstore.bak did not change.

   is(ssBakData, gSSBakData, "sessionstore.bak is unchanged.");

 });

 add_task(function* cleanup() {

   // Cleaning up after the test: removing the sessionstore.bak file.

   yield OS.File.remove(backupPath);

 });