Bug 1676296 Part 1: XPCOM component for Windows Task Scheduler. r=mhowell

Differential Revision: https://phabricator.services.mozilla.com/D97841

toolkit/components/moz.build

@@ -110,6 +110,9 @@ DIRS += ["captivedetect"]
 if CONFIG["OS_TARGET"] != "Android":
     DIRS += ["terminator"]
 
+if CONFIG["MOZ_UPDATE_AGENT"]:
+    DIRS += ["taskscheduler"]
+
 DIRS += ["build"]
 
 if CONFIG["MOZ_WIDGET_TOOLKIT"] == "windows":

toolkit/components/taskscheduler/components.conf

@@ -0,0 +1,18 @@
+# -*- Mode: python; indent-tabs-mode: nil; tab-width: 40 -*-
+# vim: set filetype=python:
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+Classes = []
+
+if buildconfig.substs['OS_TARGET'] == 'WINNT':
+    Classes += [
+        {
+            'cid': '{e2113dfc-8efe-43a1-8a20-ad720dd771d6}',
+            'contract_ids': ['@mozilla.org/win-task-scheduler-service;1'],
+            'type': 'nsWinTaskSchedulerService',
+            'headers': ['nsWinTaskScheduler.h'],
+            'processes': ProcessSelector.MAIN_PROCESS_ONLY,
+        },
+    ]

toolkit/components/taskscheduler/moz.build

@@ -0,0 +1,23 @@
+# -*- Mode: python; indent-tabs-mode: nil; tab-width: 40 -*-
+# vim: set filetype=python:
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+with Files("**"):
+    BUG_COMPONENT = ("Toolkit", "Application Update")
+
+XPCSHELL_TESTS_MANIFESTS += ["tests/xpcshell/xpcshell.ini"]
+
+XPIDL_MODULE = "taskscheduler"
+XPCOM_MANIFESTS += ["components.conf"]
+
+# This whole component is currently Windows-only, but a Mac implementation is planned.
+# Only the Windows C++ interface is an XPCOM component.
+if CONFIG["OS_TARGET"] == "WINNT":
+    XPIDL_SOURCES += ["nsIWinTaskSchedulerService.idl"]
+    EXPORTS += ["nsWinTaskScheduler.h"]
+    SOURCES += ["nsWinTaskScheduler.cpp"]
+    OS_LIBS += ["taskschd"]
+
+FINAL_LIBRARY = "xul"

toolkit/components/taskscheduler/nsIWinTaskSchedulerService.idl

@@ -0,0 +1,104 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsISupports.idl"
+
+/**
+ * An interface for Windows Task Scheduler 2.0.
+ * Documentation for the underlying APIs can be found at
+ * https://docs.microsoft.com/en-us/windows/win32/taskschd/task-scheduler-start-page
+ */
+[scriptable, main_process_scriptable_only, uuid(a8d36901-0b6a-46c3-a214-a9e1d5d6047a)]
+interface nsIWinTaskSchedulerService : nsISupports
+{
+  /**
+   * Register (create) a task from an XML definition.
+   * The task will be created so that it only runs as the current user
+   * (TASK_LOGON_INTERACTIVE_TOKEN).
+   *
+   * @throws NS_ERROR_FILE_NOT_FOUND if the folder does not exist.
+   * @throws NS_ERROR_FILE_ALREADY_EXISTS if the task already existed and aUpdateExisting is false.
+   *
+   * @param aFolderName     Full name of the folder in which to create the task, starting with "\".
+   *
+   * @param aTaskName       Name of the task.
+   *
+   * @param aDefinitionXML  XML definition of the task. This is passed directly to Task Scheduler,
+   *                        see the schema at
+   *                        https://docs.microsoft.com/en-us/windows/win32/taskschd/task-scheduler-schema
+   *
+   * @param aUpdateExisting Whether to update an existing task with the same name, default false.
+   */
+  void registerTask(in wstring aFolderName,
+                    in wstring aTaskName,
+                    in wstring aDefinitionXML,
+                    [optional] in boolean aUpdateExisting);
+
+  /**
+   * Validate the XML task definition with Task Scheduler without creating a task, for testing.
+   * Doesn't throw if only the final ITaskFolder::RegisterTask() fails.
+   *
+   * @param aDefinitionXML      Definition to validate.
+   * @return                    HRESULT from ITaskFolder::RegisterTask()
+   *                            Success should be S_OK (0). XML validation failure could be one of
+   *                            SCHED_E_UNEXPECTED_NODE, SCHED_E_NAMESPACE, SCHED_E_INVALIDVALUE,
+   *                            SCHED_E_MISSINGNODE, SCHED_E_MALFORMEDXML, but there may be others.
+   */
+  long validateTaskDefinition(in wstring aDefinitionXML);
+
+  /**
+   * Get the registration information for a task.
+   *
+   * @throws NS_ERROR_FILE_NOT_FOUND if the folder or task do not exist.
+   *
+   * @param aFolderName     Full name of the folder containing the task, starting with "\".
+   * @param aTaskName       Name of the task to read.
+   * @return                Registration information for the task, as XML text.
+   */
+  AString getTaskXML(in wstring aFolderName, in wstring aTaskName);
+
+  /**
+   * Delete a task.
+   *
+   * @throws NS_ERROR_FILE_NOT_FOUND if the folder or task do not exist.
+   *
+   * @param aFolderName     Full name of the folder containing the task, starting with "\".
+   * @param aTaskName       Name of the task to delete.
+   */
+  void deleteTask(in wstring aFolderName, in wstring aTaskName);
+
+  /**
+   * List the names of all tasks in a task folder.
+   *
+   * @throws NS_ERROR_FILE_NOT_FOUND if the folder doesn't exist.
+   *
+   * @param aFolderName     The full name of the task folder to enumerate, starting with "\".
+   *
+   * @return                An array with the names of the tasks found.
+   */
+  Array<AString> getFolderTasks(in wstring aFolderName);
+
+  /**
+   * Create a new task subfolder under a given parent folder.
+   *
+   * @throws NS_ERROR_FILE_NOT_FOUND if the parent folder does not exist.
+   * @throws NS_ERROR_FILE_ALREADY_EXISTS if the subfolder already exists.
+   *
+   * @param aParentFolderName       Immediate parent for the new folder, starting with "\".
+   * @param aSubFolderName          Name of the new folder to create.
+   */
+  void createFolder(in wstring aParentFolderName, in wstring aSubFolderName);
+
+  /**
+   * Delete a folder.
+   *
+   * @throws NS_ERROR_FILE_NOT_FOUND if the parent folder does not exist.
+   * @throws NS_ERROR_FILE_DIR_NOT_EMPTY if the folder was not empty.
+   *
+   * @param aParentFolderName       Immediate parent of the folder to delete, starting with "\".
+   * @param aSubFolderName          Name of the folder to delete.
+   */
+  void deleteFolder(in wstring aParentFolderName, in wstring aSubFolderName);
+};

toolkit/components/taskscheduler/nsWinTaskScheduler.cpp

@@ -0,0 +1,308 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode:nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsWinTaskScheduler.h"
+
+#include <windows.h>
+#include <comdef.h>
+#include <taskschd.h>
+
+#include "nsString.h"
+
+#include "mozilla/RefPtr.h"
+#include "mozilla/ResultVariant.h"
+
+using namespace mozilla;
+
+struct SysFreeStringDeleter {
+  void operator()(BSTR aPtr) { ::SysFreeString(aPtr); }
+};
+using BStrPtr = mozilla::UniquePtr<OLECHAR, SysFreeStringDeleter>;
+
+static nsresult ToNotFoundOrFailure(HRESULT hr) {
+  if (hr == HRESULT_FROM_WIN32(ERROR_FILE_NOT_FOUND)) {
+    return NS_ERROR_FILE_NOT_FOUND;
+  } else {
+    return NS_ERROR_FAILURE;
+  }
+}
+
+static nsresult ToAlreadyExistsOrFailure(HRESULT hr) {
+  if (hr == HRESULT_FROM_WIN32(ERROR_ALREADY_EXISTS)) {
+    return NS_ERROR_FILE_ALREADY_EXISTS;
+  } else {
+    return NS_ERROR_FAILURE;
+  }
+}
+
+[[nodiscard]] static Result<RefPtr<ITaskFolder>, HRESULT> GetTaskFolder(
+    const char16_t* aFolderName) {
+  HRESULT hr;
+  RefPtr<ITaskService> scheduler = nullptr;
+
+  hr = CoCreateInstance(CLSID_TaskScheduler, nullptr, CLSCTX_INPROC_SERVER,
+                        IID_ITaskService, getter_AddRefs(scheduler));
+  if (FAILED(hr)) {
+    return Err(hr);
+  }
+
+  // Connect to the local Task Scheduler.
+  hr = scheduler->Connect(VARIANT{}, VARIANT{}, VARIANT{}, VARIANT{});
+  if (FAILED(hr)) {
+    return Err(hr);
+  }
+
+  BStrPtr bstrFolderName =
+      BStrPtr(::SysAllocString(reinterpret_cast<const OLECHAR*>(aFolderName)));
+
+  RefPtr<ITaskFolder> folder = nullptr;
+  hr = scheduler->GetFolder(bstrFolderName.get(), getter_AddRefs(folder));
+  if (FAILED(hr)) {
+    return Err(hr);
+  }
+
+  return folder;
+}
+
+[[nodiscard]] static Result<RefPtr<IRegisteredTask>, HRESULT> GetRegisteredTask(
+    const char16_t* aFolderName, const char16_t* aTaskName) {
+  auto folder = GetTaskFolder(aFolderName);
+  if (!folder.isOk()) {
+    return Err(folder.unwrapErr());
+  }
+
+  BStrPtr bstrTaskName =
+      BStrPtr(::SysAllocString(reinterpret_cast<const OLECHAR*>(aTaskName)));
+
+  RefPtr<IRegisteredTask> task = nullptr;
+  HRESULT hr =
+      folder.unwrap()->GetTask(bstrTaskName.get(), getter_AddRefs(task));
+  if (FAILED(hr)) {
+    return Err(hr);
+  }
+
+  return task;
+}
+
+NS_IMPL_ISUPPORTS(nsWinTaskSchedulerService, nsIWinTaskSchedulerService)
+
+NS_IMETHODIMP
+nsWinTaskSchedulerService::GetTaskXML(const char16_t* aFolderName,
+                                      const char16_t* aTaskName,
+                                      nsAString& aResult) {
+  if (!aFolderName || !aTaskName) {
+    return NS_ERROR_NULL_POINTER;
+  }
+
+  auto task = GetRegisteredTask(aFolderName, aTaskName);
+  if (!task.isOk()) {
+    return ToNotFoundOrFailure(task.unwrapErr());
+  }
+
+  {
+    BSTR bstrXml = nullptr;
+    if (FAILED(task.unwrap()->get_Xml(&bstrXml))) {
+      return NS_ERROR_FAILURE;
+    }
+
+    aResult.Assign(bstrXml, ::SysStringLen(bstrXml));
+    ::SysFreeString(bstrXml);
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsWinTaskSchedulerService::RegisterTask(const char16_t* aFolderName,
+                                        const char16_t* aTaskName,
+                                        const char16_t* aDefinitionXML,
+                                        bool aUpdateExisting) {
+  if (!aFolderName || !aTaskName || !aDefinitionXML) {
+    return NS_ERROR_NULL_POINTER;
+  }
+
+  auto folder = GetTaskFolder(aFolderName);
+  if (!folder.isOk()) {
+    return ToNotFoundOrFailure(folder.unwrapErr());
+  }
+
+  BStrPtr bstrTaskName =
+      BStrPtr(::SysAllocString(reinterpret_cast<const OLECHAR*>(aTaskName)));
+  BStrPtr bstrXml = BStrPtr(
+      ::SysAllocString(reinterpret_cast<const OLECHAR*>(aDefinitionXML)));
+  LONG flags = aUpdateExisting ? TASK_CREATE_OR_UPDATE : TASK_CREATE;
+  TASK_LOGON_TYPE logonType = TASK_LOGON_INTERACTIVE_TOKEN;
+
+  // The outparam is not needed, but not documented as optional.
+  RefPtr<IRegisteredTask> unusedTaskOutput = nullptr;
+  HRESULT hr = folder.unwrap()->RegisterTask(
+      bstrTaskName.get(), bstrXml.get(), flags, VARIANT{} /* userId */,
+      VARIANT{} /* password */, logonType, VARIANT{} /* sddl */,
+      getter_AddRefs(unusedTaskOutput));
+
+  if (FAILED(hr)) {
+    return ToAlreadyExistsOrFailure(hr);
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsWinTaskSchedulerService::ValidateTaskDefinition(
+    const char16_t* aDefinitionXML, int32_t* aResult) {
+  if (!aDefinitionXML) {
+    return NS_ERROR_NULL_POINTER;
+  }
+
+  auto folder = GetTaskFolder(reinterpret_cast<const char16_t*>(L"\\"));
+  if (!folder.isOk()) {
+    return NS_ERROR_FAILURE;
+  }
+
+  BStrPtr bstrXml = BStrPtr(
+      ::SysAllocString(reinterpret_cast<const OLECHAR*>(aDefinitionXML)));
+  LONG flags = TASK_VALIDATE_ONLY;
+  TASK_LOGON_TYPE logonType = TASK_LOGON_INTERACTIVE_TOKEN;
+
+  // The outparam is not needed, but not documented as optional.
+  RefPtr<IRegisteredTask> unusedTaskOutput = nullptr;
+  HRESULT hr = folder.unwrap()->RegisterTask(
+      nullptr /* path */, bstrXml.get(), flags, VARIANT{} /* userId */,
+      VARIANT{} /* password */, logonType, VARIANT{} /* sddl */,
+      getter_AddRefs(unusedTaskOutput));
+
+  if (aResult) {
+    *aResult = hr;
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsWinTaskSchedulerService::DeleteTask(const char16_t* aFolderName,
+                                      const char16_t* aTaskName) {
+  if (!aFolderName || !aTaskName) {
+    return NS_ERROR_NULL_POINTER;
+  }
+
+  auto folder = GetTaskFolder(aFolderName);
+  if (!folder.isOk()) {
+    return ToNotFoundOrFailure(folder.unwrapErr());
+  }
+
+  BStrPtr bstrTaskName =
+      BStrPtr(::SysAllocString(reinterpret_cast<const OLECHAR*>(aTaskName)));
+
+  HRESULT hr = folder.unwrap()->DeleteTask(bstrTaskName.get(), 0 /* flags */);
+  if (FAILED(hr)) {
+    return ToNotFoundOrFailure(hr);
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsWinTaskSchedulerService::GetFolderTasks(const char16_t* aFolderName,
+                                          nsTArray<nsString>& aResult) {
+  if (!aFolderName) {
+    return NS_ERROR_NULL_POINTER;
+  }
+
+  auto folder = GetTaskFolder(aFolderName);
+  if (!folder.isOk()) {
+    return ToNotFoundOrFailure(folder.unwrapErr());
+  }
+
+  RefPtr<IRegisteredTaskCollection> taskCollection = nullptr;
+  if (FAILED(folder.unwrap()->GetTasks(TASK_ENUM_HIDDEN,
+                                       getter_AddRefs(taskCollection)))) {
+    return NS_ERROR_FAILURE;
+  }
+
+  LONG taskCount = 0;
+  if (FAILED(taskCollection->get_Count(&taskCount))) {
+    return NS_ERROR_FAILURE;
+  }
+
+  aResult.Clear();
+
+  for (LONG i = 0; i < taskCount; ++i) {
+    RefPtr<IRegisteredTask> task = nullptr;
+
+    // nb: Collections are indexed from 1.
+    if (FAILED(taskCollection->get_Item(_variant_t(i + 1),
+                                        getter_AddRefs(task)))) {
+      return NS_ERROR_FAILURE;
+    }
+
+    BStrPtr bstrTaskName;
+    {
+      BSTR tempTaskName = nullptr;
+      if (FAILED(task->get_Name(&tempTaskName))) {
+        return NS_ERROR_FAILURE;
+      }
+      bstrTaskName = BStrPtr(tempTaskName);
+    }
+
+    aResult.AppendElement(nsString(bstrTaskName.get()));
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsWinTaskSchedulerService::CreateFolder(const char16_t* aParentFolderName,
+                                        const char16_t* aSubFolderName) {
+  if (!aParentFolderName || !aSubFolderName) {
+    return NS_ERROR_NULL_POINTER;
+  }
+
+  auto parentFolder = GetTaskFolder(aParentFolderName);
+  if (!parentFolder.isOk()) {
+    return ToNotFoundOrFailure(parentFolder.unwrapErr());
+  }
+
+  BStrPtr bstrSubFolderName = BStrPtr(
+      ::SysAllocString(reinterpret_cast<const OLECHAR*>(aSubFolderName)));
+
+  HRESULT hr = parentFolder.unwrap()->CreateFolder(bstrSubFolderName.get(),
+                                                   VARIANT{},  // sddl
+                                                   nullptr);   // ppFolder
+
+  if (FAILED(hr)) {
+    return ToAlreadyExistsOrFailure(hr);
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsWinTaskSchedulerService::DeleteFolder(const char16_t* aParentFolderName,
+                                        const char16_t* aSubFolderName) {
+  if (!aParentFolderName || !aSubFolderName) {
+    return NS_ERROR_NULL_POINTER;
+  }
+
+  auto parentFolder = GetTaskFolder(aParentFolderName);
+  if (!parentFolder.isOk()) {
+    return ToNotFoundOrFailure(parentFolder.unwrapErr());
+  }
+
+  BStrPtr bstrSubFolderName = BStrPtr(
+      ::SysAllocString(reinterpret_cast<const OLECHAR*>(aSubFolderName)));
+
+  HRESULT hr = parentFolder.unwrap()->DeleteFolder(bstrSubFolderName.get(),
+                                                   0 /* flags */);
+
+  if (FAILED(hr)) {
+    if (hr == HRESULT_FROM_WIN32(ERROR_DIR_NOT_EMPTY)) {
+      return NS_ERROR_FILE_DIR_NOT_EMPTY;
+    } else {
+      return ToNotFoundOrFailure(hr);
+    }
+  }
+
+  return NS_OK;
+}

toolkit/components/taskscheduler/nsWinTaskScheduler.h

@@ -0,0 +1,22 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef WINTASKSCHEDULER_H_
+#define WINTASKSCHEDULER_H_
+
+#include "nsIWinTaskSchedulerService.h"
+
+class nsWinTaskSchedulerService : public nsIWinTaskSchedulerService {
+ public:
+  NS_DECL_ISUPPORTS
+  NS_DECL_NSIWINTASKSCHEDULERSERVICE
+
+  nsWinTaskSchedulerService() = default;
+
+ protected:
+  virtual ~nsWinTaskSchedulerService() = default;
+};
+
+#endif /* WINTASKSCHEDULER_H_ */

toolkit/components/taskscheduler/tests/xpcshell/test_WinTaskSchedulerService.js

@@ -0,0 +1,191 @@
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/
+ */
+"use strict";
+
+// Unit tests for access to the Windows Task Scheduler via nsIWinTaskSchedulerService.
+
+const svc = Cc["@mozilla.org/win-task-scheduler-service;1"].getService(
+  Ci.nsIWinTaskSchedulerService
+);
+
+const uuidGenerator = Cc["@mozilla.org/uuid-generator;1"].getService(
+  Ci.nsIUUIDGenerator
+);
+
+function randomName() {
+  return (
+    "moz-taskschd-test-" +
+    uuidGenerator
+      .generateUUID()
+      .toString()
+      .slice(1, -1)
+  );
+}
+
+const gParentFolderName = randomName();
+const gParentFolderPath = `\\${gParentFolderName}`;
+const gSubFolderName = randomName();
+const gSubFolderPath = `\\${gParentFolderName}\\${gSubFolderName}`;
+// This folder will not be created
+const gMissingFolderName = randomName();
+const gMissingFolderPath = `\\${gParentFolderName}\\${gMissingFolderName}`;
+
+const gValidTaskXML = `<Task xmlns="http://schemas.microsoft.com/windows/2004/02/mit/task">
+  <Triggers />
+  <Settings>
+    <Enabled>false</Enabled>
+  </Settings>
+  <Actions>
+    <Exec>
+      <Command>xyz123.exe</Command>
+    </Exec>
+  </Actions>
+</Task>`;
+
+// Missing actions
+const gInvalidTaskXML = `<Task xmlns="http://schemas.microsoft.com/windows/2004/02/mit/task">
+  <Triggers />
+  <Settings>
+    <Enabled>false</Enabled>
+  </Settings>
+</Task>`;
+
+function cleanup() {
+  let tasksToDelete = svc.getFolderTasks(gSubFolderPath);
+
+  for (const task of tasksToDelete) {
+    svc.deleteTask(gSubFolderPath, task);
+  }
+
+  svc.deleteFolder(gParentFolderPath, gSubFolderName);
+
+  svc.deleteFolder("\\", gParentFolderPath);
+}
+
+registerCleanupFunction(() => {
+  try {
+    cleanup();
+  } catch (_ex) {
+    // Folders may not exist
+  }
+});
+
+add_task(async function test_svc() {
+  /***** FOLDERS *****/
+
+  // Try creating subfolder before parent folder exists
+  Assert.throws(
+    () => svc.createFolder(gParentFolderPath, gSubFolderName),
+    /NS_ERROR_FILE_NOT_FOUND/
+  );
+
+  // Create parent folder
+  svc.createFolder("\\", gParentFolderName);
+
+  // Create subfolder
+  svc.createFolder(gParentFolderPath, gSubFolderName);
+
+  // Try creating existing folder
+  Assert.throws(
+    () => svc.createFolder(gParentFolderPath, gSubFolderName),
+    /NS_ERROR_FILE_ALREADY_EXISTS/
+  );
+
+  // Try deleting nonexistent subfolder
+  Assert.throws(
+    () => svc.deleteFolder(gParentFolderPath, gMissingFolderName),
+    /NS_ERROR_FILE_NOT_FOUND/
+  );
+
+  /***** TASKS *****/
+  const taskNames = [randomName(), randomName(), randomName()];
+
+  // Try enumerating nonexistent subfolder
+  Assert.throws(
+    () => svc.getFolderTasks(gMissingFolderPath),
+    /NS_ERROR_FILE_NOT_FOUND/
+  );
+
+  // List empty subfolder
+  Assert.deepEqual(svc.getFolderTasks(gSubFolderPath), []);
+
+  // Try to create task in nonexistent subfolder
+  Assert.throws(
+    () => svc.registerTask(gMissingFolderPath, taskNames[0], gValidTaskXML),
+    /NS_ERROR_FILE_NOT_FOUND/
+  );
+
+  // Create task 0
+
+  svc.registerTask(gSubFolderPath, taskNames[0], gValidTaskXML);
+
+  // Try to recreate task 0
+  Assert.throws(
+    () => svc.registerTask(gSubFolderPath, taskNames[0], gValidTaskXML),
+    /NS_ERROR_FILE_ALREADY_EXISTS/
+  );
+
+  // Update task 0
+  svc.registerTask(
+    gSubFolderPath,
+    taskNames[0],
+    gValidTaskXML,
+    true /* aUpdateExisting */
+  );
+
+  // Read back XML
+  Assert.ok(svc.getTaskXML(gSubFolderPath, taskNames[0]));
+
+  // Create remaining tasks
+  for (const task of taskNames.slice(1)) {
+    svc.registerTask(gSubFolderPath, task, gValidTaskXML);
+  }
+
+  // Try to create with invalid XML
+  Assert.throws(
+    () => svc.registerTask(gSubFolderPath, randomName(), gInvalidTaskXML),
+    /NS_ERROR_FAILURE/
+  );
+
+  // Validate XML
+  Assert.equal(svc.validateTaskDefinition(gValidTaskXML), 0 /* S_OK */);
+
+  // Try to validate invalid XML
+  Assert.notEqual(svc.validateTaskDefinition(gInvalidTaskXML), 0 /* S_OK */);
+
+  // Test enumeration
+  {
+    let foundTasks = svc.getFolderTasks(gSubFolderPath);
+    foundTasks.sort();
+
+    let allTasks = taskNames.slice();
+    allTasks.sort();
+
+    Assert.deepEqual(foundTasks, allTasks);
+  }
+
+  // Try deleting non-empty folder
+  Assert.throws(
+    () => svc.deleteFolder(gParentFolderPath, gSubFolderName),
+    /NS_ERROR_FILE_DIR_NOT_EMPTY/
+  );
+
+  const missingTaskName = randomName();
+
+  // Try deleting non-existent task
+  Assert.throws(
+    () => svc.deleteTask(gSubFolderName, missingTaskName),
+    /NS_ERROR_FILE_NOT_FOUND/
+  );
+
+  // Try reading non-existent task
+  Assert.throws(
+    () => svc.getTaskXML(gSubFolderPath, missingTaskName),
+    /NS_ERROR_FILE_NOT_FOUND/
+  );
+
+  /***** Cleanup *****/
+  // Explicitly call cleanup() to test that it removes the folder without error.
+  cleanup();
+});

toolkit/components/taskscheduler/tests/xpcshell/xpcshell.ini

@@ -0,0 +1,2 @@
+[test_WinTaskSchedulerService.js]
+run-if = os == "win" # Test of Windows only service