tests: Add accounts_service mock service

This is a shrunk copy of the accounts_service.py service previously
found in upstream python-dbusmock. It also adds parental control
properties to make GNOME Shell happy.

Part-of: <https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/1349>

tests/dbusmock-templates/accounts_service.py

@@ -0,0 +1,136 @@
+'''Accounts Service D-Bus mock template'''
+
+# This program is free software; you can redistribute it and/or modify it under
+# the terms of the GNU Lesser General Public License as published by the Free
+# Software Foundation; either version 3 of the License, or (at your option) any
+# later version.  See http://www.gnu.org/copyleft/lgpl.html for the full text
+# of the license.
+
+__author__ = 'Marco Trevisan'
+__email__ = 'marco.trevisan@canonical.com'
+__copyright__ = '(c) 2021 Canonical Ltd.'
+__license__ = 'LGPL 3+'
+
+import sys
+import time
+
+import dbus
+import dbusmock
+from dbusmock import MOCK_IFACE, mockobject
+
+BUS_NAME = 'org.freedesktop.Accounts'
+MAIN_OBJ = '/org/freedesktop/Accounts'
+MAIN_IFACE = 'org.freedesktop.Accounts'
+USER_IFACE = MAIN_IFACE + '.User'
+SYSTEM_BUS = True
+
+DEFAULT_USER_PASSWORD = 'Pa$$wo0rd'
+
+
+def get_user_path(uid):
+    return f'/org/freedesktop/Accounts/User{uid}'
+
+
+def load(mock, parameters=None):
+    parameters = parameters if parameters else {}
+    mock.mock_users = {}
+    mock.users_auto_uids = 2000
+
+    mock.AddProperties(MAIN_IFACE, {
+        'HasNoUsers': dbus.Boolean(True),
+        'HasMultipleUsers': dbus.Boolean(False),
+    })
+
+    for uid, name in parameters.get('users', {}):
+        mock.AddUser(uid, name, '', {})
+
+
+@dbus.service.method(MOCK_IFACE, in_signature='xssa{sv}',
+                     out_signature='o')
+def AddUser(self, uid, username, password, overrides):
+    '''Add user via uid and username and optionally overriding properties
+
+    Returns the new object path.
+    '''
+    path = get_user_path(uid)
+    default_props = {
+        'Uid': dbus.UInt64(uid),
+        'UserName': username,
+        'RealName': username[0].upper() + username[1:] + ' Fake',
+        'AccountType': dbus.Int32(1),
+        'AutomaticLogin': False,
+        'BackgroundFile': '',
+        'Email': f'{username}@python-dbusmock.org',
+        'FormatsLocale': 'C',
+        'HomeDirectory': f'/nonexisting/mock-home/{username}',
+        'IconFile': '',
+        'InputSources': dbus.Array([], signature='a{ss}'),
+        'Language': 'C',
+        'LocalAccount': True,
+        'Location': '',
+        'Locked': False,
+        'LoginFrequency': dbus.UInt64(0),
+        'LoginHistory': dbus.Array([], signature='(xxa{sv})'),
+        'LoginTime': dbus.Int64(0),
+        'PasswordHint': 'Remember it, come on!',
+        'PasswordMode': 0,
+        'Session': 'mock-session',
+        'SessionType': 'wayland',
+        'Shell': '/usr/bin/zsh',
+        'SystemAccount': False,
+        'XHasMessages': False,
+        'XKeyboardLayouts': dbus.Array([], signature='s'),
+        'XSession': 'mock-xsession',
+    }
+    default_props.update(overrides if overrides else {})
+    self.AddObject(path, USER_IFACE, default_props, [])
+    user_object = mockobject.objects[path]
+
+    user_object.AddProperty(
+            'com.endlessm.ParentalControls.AppFilter',
+            'AppFilter', dbus.Struct([
+                             False, dbus.Array(signature='s')
+                         ], variant_level=1),
+            )
+
+    user = mockobject.objects[path]
+    user.password = password
+    user.properties = default_props
+    self.mock_users[uid] = default_props
+
+    self.EmitSignal(MAIN_IFACE, 'UserAdded', 'o', [path])
+
+    self.UpdateProperties(MAIN_IFACE, {
+        'HasNoUsers': dbus.Boolean(len(self.mock_users) == 0),
+        'HasMultipleUsers': dbus.Boolean(len(self.mock_users) > 1),
+    })
+
+    return path
+
+
+@dbus.service.method(MOCK_IFACE, in_signature='', out_signature='ao')
+def ListMockUsers(self):
+    """ List the mock users that have been created """
+    return [get_user_path(uid) for uid in self.mock_users.keys()]
+
+
+@dbus.service.method(MAIN_IFACE, in_signature='x', out_signature='o')
+def FindUserById(_self, uid):
+    """ Finds an user by its user id """
+    user = mockobject.objects.get(get_user_path(uid), None)
+    if not user:
+        raise dbus.exceptions.DBusException(
+            'No such user exists',
+            name='org.freedesktop.Accounts.Error.Failed')
+    return get_user_path(uid)
+
+
+@dbus.service.method(MAIN_IFACE, in_signature='s', out_signature='o')
+def FindUserByName(self, username):
+    """ Finds an user form its name """
+    try:
+        [user_id] = [uid for uid, props in self.mock_users.items()
+                     if props['UserName'] == username]
+    except ValueError as e:
+        raise dbus.exceptions.DBusException(f'No such user exists: {e}', name='org.freedesktop.Accounts.Error.Failed')
+    return get_user_path(user_id)