Quickstart base structure for views.

quickstart/tests/cli/test_views.py

+# This file is part of the Juju Quickstart Plugin, which lets users set up a
+# Juju environment in very few steps (https://launchpad.net/juju-quickstart).
+# Copyright (C) 2013 Canonical Ltd.
+#
+# This program is free software: you can redistribute it and/or modify it under
+# the terms of the GNU Affero General Public License version 3, as published by
+# the Free Software Foundation.
+#
+# This program is distributed in the hope that it will be useful, but WITHOUT
+# ANY WARRANTY; without even the implied warranties of MERCHANTABILITY,
+# SATISFACTORY QUALITY, or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+# Affero General Public License for more details.
+#
+# You should have received a copy of the GNU Affero General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+"""Tests for the Juju Quickstart CLI application views."""
+
+from __future__ import unicode_literals
+
+from contextlib import contextmanager
+import unittest
+
+import mock
+
+from quickstart.cli import (
+    ui,
+    views,
+)
+
+
+class TestShow(unittest.TestCase):
+
+    @contextmanager
+    def patch_setup_urwid_app(self, run_side_effect=None):
+        """Patch the base.setup_urwid_app function.
+
+        The context manager returns a tuple (mock_loop, mock_app) containing
+        the two mock objects returned by the mock call.
+
+        The run_side_effect argument can be provided to specify the side
+        effects of the mock_loop.run call.
+        """
+        mock_loop = mock.Mock()
+        mock_loop.run = mock.Mock(side_effect=run_side_effect)
+        mock_setup_urwid_app = mock.Mock(return_value=(mock_loop, mock.Mock()))
+        setup_urwid_app_path = 'quickstart.cli.views.base.setup_urwid_app'
+        with mock.patch(setup_urwid_app_path, mock_setup_urwid_app):
+            yield mock_setup_urwid_app()
+
+    def test_show_view(self):
+        # The loop and app objects are properly used by the show function:
+        # the loop is run and the app is passed to the view.
+        view = mock.Mock()
+        with self.patch_setup_urwid_app() as (mock_loop, mock_app):
+            views.show(view)
+        view.assert_called_once_with(mock_app)
+        mock_loop.run.assert_called_once_with()
+
+    def test_view_exit(self):
+        # An ui.AppExit correctly quits the application. The return value
+        # encapsulated on the exception is also returned by the show function.
+        view = mock.Mock()
+        run_side_effect = ui.AppExit('bad wolf')
+        with self.patch_setup_urwid_app(run_side_effect=run_side_effect):
+            return_value = views.show(view)
+        self.assertEqual('bad wolf', return_value)
+
+    def test_unhandled_input(self):
+        # The unhandled_input callable is properly set up and registered to
+        # the main loop.
+        view = mock.Mock(return_value=42)
+        with self.patch_setup_urwid_app() as (mock_loop, mock_app):
+            views.show(view)
+        unhandled_input = mock_loop.set_unhandled_input.call_args[0][0]
+        with self.assertRaises(ui.AppExit) as context_manager:
+            unhandled_input(ui.EXIT_KEY)
+        self.assertEqual(42, context_manager.exception.return_value)
+
+    def test_view_arguments(self):
+        # The view is invoked passing the app and all the optional show
+        # function arguments.
+        view = mock.Mock()
+        with self.patch_setup_urwid_app() as (mock_loop, mock_app):
+            views.show(view, 'arg1', 'arg2')
+        view.assert_called_once_with(mock_app, 'arg1', 'arg2')