Merge lp:~nataliabidart/ubuntuone-control-panel/handle-errors into lp:ubuntuone-control-panel

[Natalia Bidart]

- Added decorator to handle errors from the backend (LP: #807021).

[lp:~nataliabidart/ubuntuone-control-panel/handle-errors]

216. By Natalia Bidart on 2011-09-08

Forgotten is_processing = False.

[Diego Sarmentero (diegosarmentero)]

+1

review: Approve

[Roberto Alsina (ralsina)]

+1

review: Approve

=== modified file 'data/qt/signin.ui'
--- data/qt/signin.ui	2011-08-30 23:18:35 +0000
+++ data/qt/signin.ui	2011-09-08 01:17:23 +0000
@@ -41,13 +41,6 @@
        </widget>
       </item>
       <item>
-       <widget class="QLabel" name="warning_label">
-        <property name="text">
-         <string>warning label!</string>
-        </property>
-       </widget>
-      </item>
-      <item>
        <layout class="QHBoxLayout" name="horizontalLayout">
         <item>
          <layout class="QVBoxLayout" name="verticalLayout_2">
 
=== modified file 'ubuntuone/controlpanel/cache.py'
--- ubuntuone/controlpanel/cache.py	2011-09-02 17:59:39 +0000
+++ ubuntuone/controlpanel/cache.py	2011-09-08 01:17:23 +0000
@@ -33,13 +33,18 @@
         if self.logger is not None:
             self.logger.debug('%s: started.', self.__class__.__name__)
 
-    @property
-    def backend(self):
+    def get_backend(self):
         """A cached ControlBackend instance."""
         if not self._shared_objects:
             self._shared_objects['backend'] = backend.ControlBackend()
         return self._shared_objects['backend']
 
+    def set_backend(self, new_value):
+        """Set a new ControlBackend instance."""
+        self._shared_objects['backend'] = new_value
+
+    backend = property(fget=get_backend, fset=set_backend)
+
     def clear(self):
         """Clear all cached objects."""
         self._shared_objects = {}
 
=== modified file 'ubuntuone/controlpanel/gui/qt/__init__.py'
--- ubuntuone/controlpanel/gui/qt/__init__.py	2011-09-01 17:11:16 +0000
+++ ubuntuone/controlpanel/gui/qt/__init__.py	2011-09-08 01:17:23 +0000
@@ -18,7 +18,13 @@
 
 """The Qt graphical interface for the control panel for Ubuntu One."""
 
+import collections
+import logging
+
+from functools import wraps
+
 from PyQt4 import QtGui, QtCore
+from twisted.internet import defer
 
 
 def uri_hook(uri):
@@ -53,3 +59,46 @@
     icon.icon_name = icon_name
 
     return icon
+
+
+def handle_errors(error_handler=None, logger=None):
+    """Decorator to handle errors when calling a function.
+
+    if 'error_handler' is not None, it will be yielded on if any error happens.
+
+    """
+    if logger is None:
+        logger = logging.getLogger()
+
+    def middle(f):
+        """Decorator to handle errors when calling 'f'."""
+
+        @defer.inlineCallbacks
+        @wraps(f)
+        def inner(*args, **kwargs):
+            """Call 'f' passing 'args' and 'kwargs'.
+
+            Catch any error and show a error message.
+
+            """
+            try:
+                res = yield f(*args, **kwargs)
+            except Exception, e:  # pylint: disable=W0703
+                logger.exception(f.__name__)
+            else:
+                defer.returnValue(res)
+
+            # this code will only be executed if there was an exception
+            if error_handler is not None:
+                yield error_handler()
+
+            if len(e.args) > 0 and isinstance(e.args[0], collections.Mapping):
+                msgs = e.args[0].itervalues()
+            else:
+                msgs = [e.__class__.__name__] + map(repr, e.args)
+            msg = '\n'.join(msgs)
+            QtGui.QMessageBox.warning(None, '', msg, QtGui.QMessageBox.Close)
+
+        return inner
+
+    return middle
 
=== modified file 'ubuntuone/controlpanel/gui/qt/account.py'
--- ubuntuone/controlpanel/gui/qt/account.py	2011-08-31 17:18:56 +0000
+++ ubuntuone/controlpanel/gui/qt/account.py	2011-09-08 01:17:23 +0000
@@ -45,6 +45,7 @@
         self.ui.edit_profile_button.uri = EDIT_PROFILE_LINK
         self.ui.edit_services_button.uri = EDIT_ACCOUNT_LINK
 
+    # pylint: disable=E0202
     @defer.inlineCallbacks
     def load(self):
         """Load info."""
 
=== modified file 'ubuntuone/controlpanel/gui/qt/addfolder.py'
--- ubuntuone/controlpanel/gui/qt/addfolder.py	2011-09-02 17:59:39 +0000
+++ ubuntuone/controlpanel/gui/qt/addfolder.py	2011-09-08 01:17:23 +0000
@@ -28,6 +28,7 @@
 from ubuntuone.controlpanel import cache
 from ubuntuone.controlpanel.logger import setup_logging
 from ubuntuone.controlpanel.gui import FOLDER_INVALID_PATH
+from ubuntuone.controlpanel.gui.qt import handle_errors
 
 
 logger = setup_logging('qt.addfolder')
@@ -50,6 +51,7 @@
         self.clicked.connect(self.on_clicked)
 
     @QtCore.pyqtSlot()
+    @handle_errors(logger=logger)
     @defer.inlineCallbacks
     def on_clicked(self):
         """The 'Sync another folder' button was clicked."""
 
=== modified file 'ubuntuone/controlpanel/gui/qt/controlpanel.py'
--- ubuntuone/controlpanel/gui/qt/controlpanel.py	2011-09-01 17:11:16 +0000
+++ ubuntuone/controlpanel/gui/qt/controlpanel.py	2011-09-08 01:17:23 +0000
@@ -72,6 +72,7 @@
         self.ui.switcher.setCurrentWidget(self.ui.management)
         self.is_processing = False
 
+    # pylint: disable=E0202
     @defer.inlineCallbacks
     def load(self):
         """Load info."""
 
=== modified file 'ubuntuone/controlpanel/gui/qt/device.py'
--- ubuntuone/controlpanel/gui/qt/device.py	2011-09-02 17:59:39 +0000
+++ ubuntuone/controlpanel/gui/qt/device.py	2011-09-08 01:17:23 +0000
@@ -27,8 +27,13 @@
 )
 from ubuntuone.controlpanel import cache
 from ubuntuone.controlpanel.gui import DEVICE_CONFIRM_REMOVE
-from ubuntuone.controlpanel.gui.qt import icon_from_name, pixmap_from_name
+from ubuntuone.controlpanel.gui.qt import (
+    handle_errors,
+    icon_from_name,
+    pixmap_from_name,
+)
 from ubuntuone.controlpanel.gui.qt.ui import device_ui
+from ubuntuone.controlpanel.logger import setup_logging
 
 COMPUTER_ICON = "computer"
 PHONE_ICON = "phone"
@@ -44,6 +49,9 @@
 YES = QtGui.QMessageBox.Yes
 
 
+logger = setup_logging('qt.device')
+
+
 def icon_name_from_type(device_type):
     """Get the icon name for the device."""
     icon_name = DEVICE_TYPE_TO_ICON_MAP.get(device_type, DEFAULT_ICON)
@@ -70,8 +78,9 @@
         pixmap = pixmap_from_name(icon_name)
         self.ui.device_icon_label.setPixmap(pixmap)
 
+    @QtCore.pyqtSlot()
+    @handle_errors(logger=logger)
     @defer.inlineCallbacks
-    @QtCore.pyqtSlot()
     def on_remove_device_button_clicked(self):
         """The user wants to remove this device."""
         msg = DEVICE_CONFIRM_REMOVE
 
=== modified file 'ubuntuone/controlpanel/gui/qt/devices.py'
--- ubuntuone/controlpanel/gui/qt/devices.py	2011-09-02 17:59:39 +0000
+++ ubuntuone/controlpanel/gui/qt/devices.py	2011-09-08 01:17:23 +0000
@@ -47,6 +47,7 @@
         super(DevicesPanel, self)._setup()
         self.ui.manage_devices_button.uri = EDIT_DEVICES_LINK
 
+    # pylint: disable=E0202
     @defer.inlineCallbacks
     def load(self):
         """Load info."""
 
=== modified file 'ubuntuone/controlpanel/gui/qt/folders.py'
--- ubuntuone/controlpanel/gui/qt/folders.py	2011-08-31 17:18:56 +0000
+++ ubuntuone/controlpanel/gui/qt/folders.py	2011-09-08 01:17:23 +0000
@@ -82,6 +82,7 @@
         icon = icon_from_name('external_icon_orange')
         self.ui.share_publish_button.setIcon(icon)
 
+    # pylint: disable=E0202
     @defer.inlineCallbacks
     def load(self):
         """Load specific tab info."""
 
=== modified file 'ubuntuone/controlpanel/gui/qt/preferences.py'
--- ubuntuone/controlpanel/gui/qt/preferences.py	2011-08-31 17:18:56 +0000
+++ ubuntuone/controlpanel/gui/qt/preferences.py	2011-09-08 01:17:23 +0000
@@ -64,6 +64,7 @@
     ui_class = preferences_ui
     logger = logger
 
+    # pylint: disable=E0202
     @defer.inlineCallbacks
     def load(self):
         """Load info."""
 
=== modified file 'ubuntuone/controlpanel/gui/qt/signin.py'
--- ubuntuone/controlpanel/gui/qt/signin.py	2011-08-31 17:18:56 +0000
+++ ubuntuone/controlpanel/gui/qt/signin.py	2011-09-08 01:17:23 +0000
@@ -19,12 +19,10 @@
 """The signin page."""
 
 from PyQt4 import QtCore
-
 from twisted.internet import defer
-from ubuntuone.platform.credentials import CredentialsError
 
 from ubuntuone.controlpanel.gui import RESET_PASSWORD_LINK
-from ubuntuone.controlpanel.gui.qt import icon_from_name
+from ubuntuone.controlpanel.gui.qt import icon_from_name, handle_errors
 from ubuntuone.controlpanel.gui.qt.ubuntuonebin import UbuntuOneBin
 from ubuntuone.controlpanel.gui.qt.ui import signin_ui
 from ubuntuone.controlpanel.logger import setup_logging, log_call
@@ -45,7 +43,6 @@
     def _setup(self):
         """Do some extra setupping for the UI."""
         super(SignInPanel, self)._setup()
-        self.ui.warning_label.setText("")
 
         self.ui.forgot_password_button.uri = RESET_PASSWORD_LINK
         icon = icon_from_name('external_icon_orange')
@@ -64,21 +61,23 @@
         self.ui.signin_button.style().unpolish(self.ui.signin_button)
         self.ui.signin_button.style().polish(self.ui.signin_button)
 
+    # pylint: disable=E0202
+    @defer.inlineCallbacks
+    def load(self):
+        """Load specific tab info."""
+        yield self.backend.get_credentials()
+
+    @QtCore.pyqtSlot()
+    @handle_errors(logger=logger)
     @log_call(logger.debug)
     @defer.inlineCallbacks
-    @QtCore.pyqtSlot()
     def on_signin_button_clicked(self):
         """The 'Sign in' button was clicked."""
-        self.ui.warning_label.setText("")
         email = unicode(self.ui.email_entry.text())
         password = unicode(self.ui.password_entry.text())
         self.is_processing = True
         try:
             result = yield self.backend.login(email=email, password=password)
-        except CredentialsError, e:
-            logger.info('on_signin_button_clicked: %r', e)
-            self.ui.warning_label.setText(e.args[0]['message'])
-        else:
             logger.info('Emitting credentialsFound for email %r.', email)
             self.credentialsFound.emit(result)
         finally:
 
=== modified file 'ubuntuone/controlpanel/gui/qt/tests/__init__.py'
--- ubuntuone/controlpanel/gui/qt/tests/__init__.py	2011-09-02 17:59:39 +0000
+++ ubuntuone/controlpanel/gui/qt/tests/__init__.py	2011-09-08 01:17:23 +0000
@@ -22,7 +22,7 @@
 import os
 import urllib
 
-from PyQt4 import QtCore
+from PyQt4 import QtGui, QtCore
 from ubuntuone.devtools.handlers import MementoHandler
 
 from ubuntuone.controlpanel import backend, cache
@@ -126,9 +126,32 @@
         return TOKEN
 
 
-class FakedConfirmDialog(object):
+class CrashyBackendException(Exception):
+    """A faked backend crash."""
+
+
+class CrashyBackend(FakedControlPanelBackend):
+    """A faked backend that crashes."""
+
+    def __init__(self, *args, **kwargs):
+        super(CrashyBackend, self).__init__(*args, **kwargs)
+        for i in self.exposed_methods + ['get_credentials']:
+            setattr(self, i, self._fail(i))
+
+    def _fail(self, f):
+        """Crash boom bang."""
+
+        def inner(*args, **kwargs):
+            """Raise a custom exception."""
+            raise CrashyBackendException(f)
+
+        return inner
+
+
+class FakedDialog(object):
     """Fake a confirmation dialog."""
 
+    Close = 0
     response = args = kwargs = None
 
     @classmethod
@@ -163,6 +186,7 @@
     innerclass_name = None
     class_ui = None
     kwargs = {}
+    logger = None
 
     def setUp(self):
         cache.Cache._shared_objects = {}
@@ -180,11 +204,25 @@
         if getattr(self.ui, 'backend', None) is not None:
             self.addCleanup(self.ui.backend._called.clear)
 
-        if getattr(self.ui, 'logger', None) is not None:
+        logger = self.logger if self.logger is not None else \
+                 getattr(self.ui, 'logger', None)
+        self.memento = None
+        if logger is not None:
             self.memento = MementoHandler()
             self.memento.setLevel(logging.DEBUG)
-            self.ui.logger.addHandler(self.memento)
-            self.addCleanup(self.ui.logger.removeHandler, self.memento)
+            logger.addHandler(self.memento)
+            self.addCleanup(logger.removeHandler, self.memento)
+
+        # default response if user does nothing
+        FakedFileDialog.response = QtCore.QString('')
+        FakedFileDialog.args = None
+        FakedFileDialog.kwargs = None
+        self.patch(QtGui, 'QFileDialog', FakedFileDialog)
+
+        FakedDialog.response = None
+        FakedDialog.args = None
+        FakedDialog.kwargs = None
+        self.patch(QtGui, 'QMessageBox', FakedDialog)
 
     def get_pixmap_data(self, pixmap):
         """Get the raw data of a QPixmap."""
 
=== modified file 'ubuntuone/controlpanel/gui/qt/tests/test_addfolder.py'
--- ubuntuone/controlpanel/gui/qt/tests/test_addfolder.py	2011-08-29 13:28:58 +0000
+++ ubuntuone/controlpanel/gui/qt/tests/test_addfolder.py	2011-09-08 01:17:23 +0000
@@ -29,7 +29,9 @@
 from ubuntuone.controlpanel.gui.qt import addfolder as gui
 from ubuntuone.controlpanel.gui.qt.tests import (
     BaseTestCase,
-    FakedConfirmDialog,
+    CrashyBackend,
+    CrashyBackendException,
+    FakedDialog,
     FakedFileDialog,
     set_path_on_file_dialog,
 )
@@ -53,20 +55,6 @@
         os.environ['HOME'] = USER_HOME
         self.addCleanup(lambda: os.environ.__setitem__('HOME', old_home))
 
-        # default response if user does nothing
-        FakedFileDialog.response = gui.QtCore.QString('')
-        FakedFileDialog.args = None
-        FakedFileDialog.kwargs = None
-        self.patch(gui.QtGui, 'QFileDialog', FakedFileDialog)
-
-        FakedConfirmDialog.response = None
-        FakedConfirmDialog.args = None
-        FakedConfirmDialog.kwargs = None
-        self.patch(gui.QtGui, 'QMessageBox', FakedConfirmDialog)
-
-        # reset backend state
-        self.ui.backend._called.clear()
-
     @defer.inlineCallbacks
     def assert_does_nothing(self, method_call):
         """Nothing happens.
@@ -103,8 +91,8 @@
         yield self.assert_does_nothing(self.ui.click)
 
         # the warning dialog was not opened
-        self.assertEqual(FakedConfirmDialog.args, None)
-        self.assertEqual(FakedConfirmDialog.kwargs, None)
+        self.assertEqual(FakedDialog.args, None)
+        self.assertEqual(FakedDialog.kwargs, None)
 
     @defer.inlineCallbacks
     def test_opens_warning_if_folder_path_not_valid(self):
@@ -116,9 +104,9 @@
 
         args = {'folder_path': folder_path, 'home_folder': USER_HOME}
         msg = gui.FOLDER_INVALID_PATH % args
-        self.assertEqual(FakedConfirmDialog.args,
+        self.assertEqual(FakedDialog.args,
                          (self.ui, '', msg, gui.CLOSE))
-        self.assertEqual(FakedConfirmDialog.kwargs, {})
+        self.assertEqual(FakedDialog.kwargs, {})
 
         yield self.assert_does_nothing(self.ui.click)
 
@@ -129,8 +117,8 @@
         yield self.ui.click()
 
         # no warning
-        self.assertEqual(FakedConfirmDialog.args, None)
-        self.assertEqual(FakedConfirmDialog.kwargs, None)
+        self.assertEqual(FakedDialog.args, None)
+        self.assertEqual(FakedDialog.kwargs, None)
         # backend called
         self.assert_backend_called('create_folder', folder_path=folder)
 
@@ -141,8 +129,8 @@
         yield self.ui.click()
 
         # no warning
-        self.assertEqual(FakedConfirmDialog.args, None)
-        self.assertEqual(FakedConfirmDialog.kwargs, None)
+        self.assertEqual(FakedDialog.args, None)
+        self.assertEqual(FakedDialog.kwargs, None)
         # backend called
         self.assert_backend_called('create_folder', folder_path=folder)
 
@@ -170,3 +158,12 @@
         yield self.ui.click()
 
         self.assertEqual(self._called, ((), {}))
+
+    @defer.inlineCallbacks
+    def test_backend_error_is_handled(self):
+        """Any error from the backend is properly handled."""
+        set_path_on_file_dialog()
+        self.patch(self.ui, 'backend', CrashyBackend())
+        yield self.ui.click()
+
+        self.assertTrue(self.memento.check_exception(CrashyBackendException))
 
=== renamed file 'ubuntuone/controlpanel/gui/qt/tests/test_urihook.py' => 'ubuntuone/controlpanel/gui/qt/tests/test_common.py'
--- ubuntuone/controlpanel/gui/qt/tests/test_urihook.py	2011-09-01 17:11:16 +0000
+++ ubuntuone/controlpanel/gui/qt/tests/test_common.py	2011-09-08 01:17:23 +0000
@@ -18,12 +18,17 @@
 
 """Tests for the uri_hook helper."""
 
+import logging
+
 from PyQt4 import QtGui, QtCore
-
 from twisted.internet import defer
 
-from ubuntuone.controlpanel.gui.qt import uri_hook
-from ubuntuone.controlpanel.gui.qt.tests import BaseTestCase
+from ubuntuone.controlpanel.logger import setup_logging
+from ubuntuone.controlpanel.gui.qt import uri_hook, handle_errors
+from ubuntuone.controlpanel.gui.qt.tests import (
+    BaseTestCase,
+    FakedDialog,
+)
 
 
 class UriHookTestCase(BaseTestCase):
@@ -45,3 +50,161 @@
         expected = 'http://foo.bar/?next=https://one.ubuntu.com/'
         uri_hook(expected)
         self.assertEqual(self._called, ((QtCore.QUrl(expected),), {}))
+
+
+class HandleErrorTestCase(BaseTestCase):
+    """Test suite for the generic error handler."""
+
+    error_handler = None
+    use_logger = False
+    logger = logging.getLogger()  # root logger
+
+    @defer.inlineCallbacks
+    def setUp(self):
+        yield super(HandleErrorTestCase, self).setUp()
+        self.called = None
+        self.result = None
+        self.failure = None
+        self.error_handler_called = None
+
+        if self.use_logger:
+            logger = self.logger
+        else:
+            logger = None
+
+        self.decorate_me = handle_errors(error_handler=self.error_handler,
+                                         logger=logger)(self._decorate_me)
+
+    @defer.inlineCallbacks
+    def _decorate_me(self, *args, **kwargs):
+        """Helper to test thye decorator."""
+        if self.failure:
+            # Raising only classes, instances or string are allowed
+            # pylint: disable=E0702
+            raise self.failure
+
+        yield
+        self.called = (args, kwargs)
+        defer.returnValue(self.result)
+
+    @defer.inlineCallbacks
+    def test_is_decorator(self):
+        """Is a decorator."""
+        yield self.decorate_me()
+
+    @defer.inlineCallbacks
+    def test_params_are_passed(self):
+        """Named and unnamed arguments are passed."""
+        args = ({}, object(), 'foo')
+        kwargs = {'1': 1, 'test': None, '0': ['a']}
+        yield self.decorate_me(*args, **kwargs)
+
+        self.assertTrue(self.called, (args, kwargs))
+
+    @defer.inlineCallbacks
+    def test_result_is_returned(self):
+        """Result is returned."""
+        self.result = object()
+        result = yield self.decorate_me()
+
+        self.assertEqual(self.result, result)
+
+    def test_name_is_preserved(self):
+        """The method name is not masqueraded."""
+        self.assertEqual(self.decorate_me.__name__, self._decorate_me.__name__)
+
+    @defer.inlineCallbacks
+    def test_exeptions_are_handled(self):
+        """Any exception is handled and logged in the root logger."""
+        msg = 'This is me failing badly.'
+        self.failure = Exception(msg)
+
+        yield self.decorate_me()
+
+        logged = self.memento.check_exception(self.failure.__class__, msg)
+        recs = '\n'.join(rec.exc_text for rec in self.memento.records)
+        self.assertTrue(logged, 'Exception must be logged, got:\n%s' % recs)
+
+    @defer.inlineCallbacks
+    def test_show_error_message(self):
+        """On error, show an error message."""
+        self.failure = Exception()
+
+        yield self.decorate_me()
+
+        msg = self.failure.__class__.__name__
+        self.assertEqual(FakedDialog.args,
+                         (None, '', msg, QtGui.QMessageBox.Close))
+        self.assertEqual(FakedDialog.kwargs, {})
+
+    @defer.inlineCallbacks
+    def test_show_error_message_if_args(self):
+        """On error, show an error message."""
+        msg1 = 'This is me failing badly.'
+        msg2 = 'More details about what went wrong.'
+        obj = object()
+        self.failure = Exception(msg1, msg2, obj)
+
+        yield self.decorate_me()
+
+        msg = '\n'.join(map(repr, (msg1, msg2, obj)))
+        msg = self.failure.__class__.__name__ + '\n' + msg
+        self.assertEqual(FakedDialog.args,
+                         (None, '', msg, QtGui.QMessageBox.Close))
+        self.assertEqual(FakedDialog.kwargs, {})
+
+    @defer.inlineCallbacks
+    def test_show_error_message_if_mapping(self):
+        """On error, show an error message."""
+        msg1 = 'This is me failing badly.'
+        msg2 = 'More details about what went wrong.'
+        errdict = {'foo': msg1, 'bar': msg2}
+        self.failure = Exception(errdict)
+
+        yield self.decorate_me()
+
+        msg = '\n'.join((msg1, msg2))
+        self.assertEqual(FakedDialog.args,
+                         (None, '', msg, QtGui.QMessageBox.Close))
+        self.assertEqual(FakedDialog.kwargs, {})
+
+    @defer.inlineCallbacks
+    def test_no_error_message_if_no_exception(self):
+        """On success, do not show an error message."""
+        yield self.decorate_me()
+
+        self.assertEqual(FakedDialog.args, None)
+        self.assertEqual(FakedDialog.kwargs, None)
+
+    @defer.inlineCallbacks
+    def test_call_error_handler(self):
+        """On success, do not execute error_handler."""
+        yield self.decorate_me()
+        self.assertFalse(self.error_handler_called)
+
+
+class HandleErrorWithCustomLoggerTestCase(HandleErrorTestCase):
+    """Test suite for the generic error handler."""
+
+    use_logger = True
+    logger = setup_logging('HandleErrorWithoutLoggerTestCase')  # custom logger
+
+
+class HandleErrorWithHandlerTestCase(HandleErrorTestCase):
+    """Test suite for the generic error handler when using a custom handler."""
+
+    @defer.inlineCallbacks
+    def error_handler(self, *a, **kw):
+        """Implement an error handler."""
+        self.error_handler_called = (a, kw)
+        yield
+
+    @defer.inlineCallbacks
+    def test_call_error_handler(self):
+        """On error, execute error_handler."""
+        msg = 'This is me failing badly.'
+        self.failure = Exception(msg)
+
+        yield self.decorate_me()
+
+        self.assertEqual(self.error_handler_called, ((), {}))
 
=== modified file 'ubuntuone/controlpanel/gui/qt/tests/test_device.py'
--- ubuntuone/controlpanel/gui/qt/tests/test_device.py	2011-09-02 17:59:39 +0000
+++ ubuntuone/controlpanel/gui/qt/tests/test_device.py	2011-09-08 01:17:23 +0000
@@ -23,7 +23,9 @@
 from ubuntuone.controlpanel.gui.qt import device as gui
 from ubuntuone.controlpanel.gui.qt.tests import (
     BaseTestCase,
-    FakedConfirmDialog,
+    CrashyBackend,
+    CrashyBackendException,
+    FakedDialog,
     SAMPLE_COMPUTER_INFO,
     SAMPLE_PHONE_INFO,
 )
@@ -41,6 +43,7 @@
     class_ui = gui.DeviceWidget
     device_id = 'zaraza'
     kwargs = {'device_id': device_id}
+    logger = gui.logger
 
     def test_has_id(self):
         """The device as an id, None by default."""
@@ -98,10 +101,7 @@
     @defer.inlineCallbacks
     def setUp(self):
         yield super(RemoveDeviceTestCase, self).setUp()
-        FakedConfirmDialog.response = gui.NO
-        FakedConfirmDialog.args = None
-        FakedConfirmDialog.kwargs = None
-        self.patch(gui.QtGui, 'QMessageBox', FakedConfirmDialog)
+        FakedDialog.response = gui.YES
 
     def test_remove_device_opens_confirmation_dialog(self):
         """A confirmation dialog is opened when user clicks 'delete device'."""
@@ -109,13 +109,13 @@
 
         msg = gui.DEVICE_CONFIRM_REMOVE
         buttons = gui.YES | gui.NO
-        self.assertEqual(FakedConfirmDialog.args,
+        self.assertEqual(FakedDialog.args,
                          (self.ui, '', msg, buttons, gui.NO))
-        self.assertEqual(FakedConfirmDialog.kwargs, {})
+        self.assertEqual(FakedDialog.kwargs, {})
 
     def test_remove_device_does_not_remove_if_answer_is_no(self):
         """The device is not removed is answer is No."""
-        FakedConfirmDialog.response = gui.NO
+        FakedDialog.response = gui.NO
         self.ui.removed.connect(self._set_called)
         self.ui.ui.remove_device_button.click()
 
@@ -124,7 +124,7 @@
 
     def test_remove_device_does_remove_if_answer_is_yes(self):
         """The device is removed is answer is Yes."""
-        FakedConfirmDialog.response = gui.YES
+        FakedDialog.response = gui.YES
         self.ui.ui.remove_device_button.click()
 
         self.assert_backend_called('remove_device', device_id=self.device_id)
@@ -138,7 +138,7 @@
             """Fire deferred when the device was removed."""
             d.callback(device_id)
 
-        FakedConfirmDialog.response = gui.YES
+        FakedDialog.response = gui.YES
         self.ui.removed.connect(self._set_called)
         self.patch(self.ui.backend, 'remove_device', check)
         self.ui.ui.remove_device_button.click()
@@ -148,8 +148,16 @@
 
     def test_remove_device_emits_signal_when_not_removed(self):
         """The signal 'removeCanceled' is emitted when user cancels removal."""
-        FakedConfirmDialog.response = gui.NO
+        FakedDialog.response = gui.NO
         self.ui.removeCanceled.connect(self._set_called)
         self.ui.ui.remove_device_button.click()
 
         self.assertEqual(self._called, ((), {}))
+
+    @defer.inlineCallbacks
+    def test_backend_error_is_handled(self):
+        """Any error from the backend is properly handled."""
+        self.patch(self.ui, 'backend', CrashyBackend())
+        yield self.ui.ui.remove_device_button.click()
+
+        self.assertTrue(self.memento.check_exception(CrashyBackendException))
 
=== modified file 'ubuntuone/controlpanel/gui/qt/tests/test_devices.py'
--- ubuntuone/controlpanel/gui/qt/tests/test_devices.py	2011-09-01 17:11:16 +0000
+++ ubuntuone/controlpanel/gui/qt/tests/test_devices.py	2011-09-08 01:17:23 +0000
@@ -22,7 +22,6 @@
 
 from ubuntuone.controlpanel.gui.qt import devices as gui
 from ubuntuone.controlpanel.gui.qt.tests import (
-    FakedConfirmDialog,
     SAMPLE_DEVICES_INFO,
 )
 from ubuntuone.controlpanel.gui.qt.tests.test_ubuntuonebin import (
@@ -41,7 +40,6 @@
     def setUp(self):
         yield super(DevicesPanelTestCase, self).setUp()
         self.ui.backend.next_result = SAMPLE_DEVICES_INFO
-        self.patch(gui.QtGui, 'QMessageBox', FakedConfirmDialog)
 
     def test_is_processing_while_asking_info(self):
         """The ui is processing while the contents are loaded."""
 
=== modified file 'ubuntuone/controlpanel/gui/qt/tests/test_folders.py'
--- ubuntuone/controlpanel/gui/qt/tests/test_folders.py	2011-09-01 17:11:16 +0000
+++ ubuntuone/controlpanel/gui/qt/tests/test_folders.py	2011-09-08 01:17:23 +0000
@@ -33,8 +33,7 @@
 )
 from ubuntuone.controlpanel.gui.qt import folders as gui
 from ubuntuone.controlpanel.gui.qt.tests import (
-    FakedConfirmDialog,
-    FakedFileDialog,
+    FakedDialog,
 )
 from ubuntuone.controlpanel.gui.qt.tests.test_ubuntuonebin import (
     UbuntuOneBinTestCase,
@@ -320,17 +319,6 @@
         # reset backend state
         self.ui.backend._called.clear()
 
-        # default response if user does nothing
-        FakedFileDialog.response = gui.QtCore.QString('')
-        FakedFileDialog.args = None
-        FakedFileDialog.kwargs = None
-        self.patch(gui.QtGui, 'QFileDialog', FakedFileDialog)
-
-        FakedConfirmDialog.response = None
-        FakedConfirmDialog.args = None
-        FakedConfirmDialog.kwargs = None
-        self.patch(gui.QtGui, 'QMessageBox', FakedConfirmDialog)
-
     def test_not_is_processing(self):
         """Before clicking the add folder button, the UI is not processing."""
         self.assertFalse(self.ui.is_processing, 'ui must not be processing')
@@ -354,10 +342,7 @@
     def setUp(self):
         yield super(FoldersPanelSubscriptionTestCase, self).setUp()
         self.patch(gui.os.path, 'exists', lambda path: True)
-        FakedConfirmDialog.response = gui.YES
-        FakedConfirmDialog.args = None
-        FakedConfirmDialog.kwargs = None
-        self.patch(gui.QtGui, 'QMessageBox', FakedConfirmDialog)
+        FakedDialog.response = gui.YES
 
         self.ui.process_info(FAKE_VOLUMES_MINIMAL_INFO)
         # the music folder
@@ -436,9 +421,9 @@
         volume_path = self.item.volume_path
         msg = gui.FOLDERS_CONFIRM_MERGE % {'folder_path': volume_path}
         buttons = gui.YES | gui.NO | gui.CANCEL
-        self.assertEqual(FakedConfirmDialog.args,
+        self.assertEqual(FakedDialog.args,
                          (self.ui, '', msg, buttons, gui.YES))
-        self.assertEqual(FakedConfirmDialog.kwargs, {})
+        self.assertEqual(FakedDialog.kwargs, {})
 
     @defer.inlineCallbacks
     def test_confirm_dialog_if_path_does_not_exist(self):
@@ -452,14 +437,13 @@
 
         yield self.ui.on_folders_itemChanged(self.item)
 
-        self.assertEqual(FakedConfirmDialog.args, None)
-        self.assertEqual(FakedConfirmDialog.kwargs, None)
+        self.assertEqual(FakedDialog.args, None)
+        self.assertEqual(FakedDialog.kwargs, None)
 
     @defer.inlineCallbacks
     def test_subscribe_does_not_call_backend_if_dialog_closed(self):
         """Backend is not called if users closes the confirmation dialog."""
-        FakedConfirmDialog.response = gui.CANCEL
-        self.patch(gui.QtGui, 'QMessageBox', FakedConfirmDialog)
+        FakedDialog.response = gui.CANCEL
 
         # make sure the item is subscribed
         self.ui.is_processing = True
@@ -468,7 +452,7 @@
 
         yield self.ui.on_folders_itemChanged(self.item)
 
-        self.assertFalse(FakedConfirmDialog.args is None, 'warning was called')
+        self.assertFalse(FakedDialog.args is None, 'warning was called')
         self.assertNotIn('change_volume_settings', self.ui.backend._called)
         self.assertFalse(self.ui.is_processing)
 
@@ -478,8 +462,7 @@
     @defer.inlineCallbacks
     def test_subscribe_does_not_call_backend_if_answer_is_no(self):
         """Backend is not called if users clicks on 'No'."""
-        FakedConfirmDialog.response = gui.NO
-        self.patch(gui.QtGui, 'QMessageBox', FakedConfirmDialog)
+        FakedDialog.response = gui.NO
 
         # make sure the item is subscribed
         self.ui.is_processing = True
@@ -488,7 +471,7 @@
 
         yield self.ui.on_folders_itemChanged(self.item)
 
-        self.assertFalse(FakedConfirmDialog.args is None, 'warning was called')
+        self.assertFalse(FakedDialog.args is None, 'warning was called')
         self.assertNotIn('change_volume_settings', self.ui.backend._called)
         self.assertFalse(self.ui.is_processing)
 
@@ -504,10 +487,10 @@
         self.ui.is_processing = False
 
         # the confirm dialog was not called so far
-        assert FakedConfirmDialog.args is None
-        assert FakedConfirmDialog.kwargs is None
+        assert FakedDialog.args is None
+        assert FakedDialog.kwargs is None
 
         yield self.ui.on_folders_itemChanged(self.item)
 
-        self.assertTrue(FakedConfirmDialog.args is None, 'dialog was not run')
-        self.assertTrue(FakedConfirmDialog.kwargs is None, 'dialog was hid')
+        self.assertTrue(FakedDialog.args is None, 'dialog was not run')
+        self.assertTrue(FakedDialog.kwargs is None, 'dialog was hid')
 
=== modified file 'ubuntuone/controlpanel/gui/qt/tests/test_signin.py'
--- ubuntuone/controlpanel/gui/qt/tests/test_signin.py	2011-08-31 17:18:56 +0000
+++ ubuntuone/controlpanel/gui/qt/tests/test_signin.py	2011-09-08 01:17:23 +0000
@@ -22,6 +22,10 @@
 
 from ubuntuone.controlpanel.gui import qt
 from ubuntuone.controlpanel.gui.qt import signin as gui
+from ubuntuone.controlpanel.gui.qt.tests import (
+    CrashyBackend,
+    CrashyBackendException,
+)
 from ubuntuone.controlpanel.gui.qt.tests.test_ubuntuonebin import (
     UbuntuOneBinTestCase,
 )
@@ -36,7 +40,7 @@
 
 def fail(*a, **kw):
     """Emit CredentialsError."""
-    raise gui.CredentialsError(MSG)
+    raise TypeError(MSG)
 
 
 class BaseSignInPanelTestCase(UbuntuOneBinTestCase):
@@ -81,10 +85,6 @@
         yield self.ui.ui.signin_button.click()
         self.assertFalse(self.ui.is_processing)
 
-    def test_warning_label_empty(self):
-        """The warning_label is empty at startup."""
-        self.assertEqual('', unicode(self.ui.ui.warning_label.text()))
-
     def test_signin_disabled_at_startup(self):
         """The signin_button is disabled at startup."""
         self.assertFalse(self.ui.ui.signin_button.isEnabled())
@@ -139,31 +139,7 @@
         yield self.ui.ui.signin_button.click()
 
         self.assertEqual(self._called, ((TOKEN,), {}))
-        self.assertEqual('', unicode(self.ui.ui.warning_label.text()))
-        self.assertFalse(self.ui.is_processing)
-
-    @defer.inlineCallbacks
-    def test_signin_credentials_error(self):
-        """Show error when CredentialsError was raised from the backend."""
-        self.patch(self.ui.backend, 'login', fail)
-        self.ui.credentialsFound.connect(self._set_called)
-        yield self.ui.ui.signin_button.click()
-
-        self.assertFalse(self._called, 'credentialsFound must not be emitted.')
-        self.assertEqual(MSG['message'],
-                         unicode(self.ui.ui.warning_label.text()))
-        self.assertFalse(self.ui.is_processing)
-        self.assertTrue(self.memento.check_info('signin_button_clicked',
-                                                repr(MSG)))
-
-    @defer.inlineCallbacks
-    def test_signin_success_after_error(self):
-        """Emit credentialsFound on signin success."""
-        self.patch(self.ui.backend, 'login', fail)  # login failed
-        yield self.ui.ui.signin_button.click()
-
-        self.patch(self.ui.backend, 'login', lambda *a, **kw: TOKEN)  # success
-        yield self.test_signin_success()
+        self.assertFalse(self.ui.is_processing)
 
     def test_signin_enabled_if_email_and_password(self):
         """Enable signin_button if email and password are non empty."""
@@ -182,3 +158,11 @@
             self.assertEqual(1, receivers)
 
             self._called = False
+
+    @defer.inlineCallbacks
+    def test_backend_error_is_handled(self):
+        """Any error from the backend is properly handled."""
+        self.patch(self.ui, 'backend', CrashyBackend())
+        yield self.ui.ui.signin_button.click()
+
+        self.assertTrue(self.memento.check_exception(CrashyBackendException))
 
=== modified file 'ubuntuone/controlpanel/gui/qt/tests/test_ubuntuonebin.py'
--- ubuntuone/controlpanel/gui/qt/tests/test_ubuntuonebin.py	2011-09-02 17:59:39 +0000
+++ ubuntuone/controlpanel/gui/qt/tests/test_ubuntuonebin.py	2011-09-08 01:17:23 +0000
@@ -18,10 +18,15 @@
 
 """Tests for the Ubuntu One Bin."""
 
+from twisted.internet import defer
 from ubuntuone.devtools.testcase import skipIfOS
 
 from ubuntuone.controlpanel.gui.qt import ubuntuonebin as gui
-from ubuntuone.controlpanel.gui.qt.tests import BaseTestCase
+from ubuntuone.controlpanel.gui.qt.tests import (
+    BaseTestCase,
+    CrashyBackend,
+    CrashyBackendException,
+)
 
 # Attribute 'yyy' defined outside __init__, access to a protected member
 # pylint: disable=W0201, W0212
@@ -45,6 +50,7 @@
     def test_is_enabled_if_not_processing(self):
         """If not processing, the UI is enabled."""
         self.ui.show()  # need to show to test widgets visibility
+        self.addCleanup(self.ui.hide)
 
         self.ui.is_processing = False
 
@@ -55,8 +61,20 @@
     def test_is_not_enabled_if_processing(self):
         """If processing, the UI is disabled."""
         self.ui.show()  # need to show to test widgets visibility
+        self.addCleanup(self.ui.hide)
 
         self.ui.is_processing = True
 
         self.assertFalse(self.ui.isEnabled())
         self.assertTrue(self.ui.overlay.isVisible())
+
+    @defer.inlineCallbacks
+    def test_backend_error_is_handled(self):
+        """Any error from the backend is properly handled."""
+        self.patch(self.ui, 'backend', CrashyBackend())
+        yield self.ui.load()
+
+        self.assertFalse(self.ui.is_processing)
+        if self.memento:
+            logged = self.memento.check_exception(CrashyBackendException)
+            self.assertTrue(logged)
 
=== modified file 'ubuntuone/controlpanel/gui/qt/ubuntuonebin.py'
--- ubuntuone/controlpanel/gui/qt/ubuntuonebin.py	2011-09-02 17:59:39 +0000
+++ ubuntuone/controlpanel/gui/qt/ubuntuonebin.py	2011-09-08 01:17:23 +0000
@@ -21,6 +21,7 @@
 from PyQt4 import QtGui
 
 from ubuntuone.controlpanel import cache
+from ubuntuone.controlpanel.gui.qt import handle_errors
 from ubuntuone.controlpanel.gui.qt.loadingoverlay import LoadingOverlay
 
 
@@ -45,6 +46,11 @@
         self._is_processing = None
         self.is_processing = False
 
+        # pylint: disable=E0202
+        handler = handle_errors(logger=self.logger,
+                                error_handler=self._error_handler)
+        self.load = handler(self.load)
+
         self._setup()
 
     def _get_is_processing(self):
@@ -64,6 +70,10 @@
 
     is_processing = property(fget=_get_is_processing, fset=_set_is_processing)
 
+    def _error_handler(self):
+        """Custom error handler, unset is_processing."""
+        self.is_processing = False
+
     def _setup(self):
         """Do some extra setupping for the UI."""
 
@@ -82,5 +92,6 @@
 
     # pylint: enable=C0103
 
+    # pylint: disable=E0202
     def load(self):
         """Load the widget with specific info."""
 
=== modified file 'ubuntuone/controlpanel/tests/test_cache.py'
--- ubuntuone/controlpanel/tests/test_cache.py	2011-09-02 18:10:13 +0000
+++ ubuntuone/controlpanel/tests/test_cache.py	2011-09-08 01:17:23 +0000
@@ -39,6 +39,13 @@
         """The backend instance is successfully created."""
         self.assertIsInstance(self.obj.backend, cache.backend.ControlBackend)
 
+    def test_set_backend(self):
+        """The backend instance is successfully assigned."""
+        expected = object()
+        assert self.obj.backend is not expected
+        self.obj.backend = expected
+        self.assertTrue(self.obj.backend is expected)
+
     def test_backend_is_cached(self):
         """The backend instance is cached."""
         obj2 = cache.Cache()