Implemented test for Progress widget

Also created a conftest file with a "default_config" fixture.

qutebrowser/test/mainwindow/conftest.py

@@ -0,0 +1,34 @@
+"""
+pytest fixtures and utilities for testing.
+
+Fixtures defined here will be visible to all test files in this directory and
+below.
+"""
+
+import pytest
+
+from qutebrowser.config.config import ConfigManager
+from qutebrowser.utils import objreg
+
+
+@pytest.yield_fixture
+def default_config():
+    """
+    Fixture that registers an empty config object into the objreg module.
+
+    Should be used by tests which create widgets that obtain their initial state
+    from the global config object.
+
+    Note:
+
+        If we declare this fixture like this:
+
+            @pytest.yield_fixture(autouse=True)
+
+        Then all tests below this file will have a default config registered
+        and ready for use. Is that desirable?
+    """
+    config_obj = ConfigManager(configdir=None, fname=None, relaxed=True)
+    objreg.register('config', config_obj)
+    yield config_obj
+    objreg.delete('config')

qutebrowser/test/mainwindow/statusbar/test_progress.py

@@ -0,0 +1,74 @@
+# vim: ft=python fileencoding=utf-8 sts=4 sw=4 et:
+
+# Copyright 2014-2015 Florian Bruhin (The Compiler) <mail@qutebrowser.org>
+#
+# This file is part of qutebrowser.
+#
+# qutebrowser is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# qutebrowser is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with qutebrowser.  If not, see <http://www.gnu.org/licenses/>.
+
+
+"""Test Percentage widget."""
+
+from collections import namedtuple
+
+import pytest
+
+from qutebrowser.browser import webview
+from qutebrowser.mainwindow.statusbar.progress import Progress
+
+
+@pytest.fixture
+def progress_widget(qtbot, default_config):
+    """
+    Creates a Progress widget and checks it initial state.
+    """
+    widget = Progress()
+    qtbot.add_widget(widget)
+    assert not widget.isVisible()
+    assert not widget.isTextVisible()
+    return widget
+
+
+def test_load_started(progress_widget):
+    """
+    Args:
+        progress_widget: Progress widget that will be tested.
+    """
+    progress_widget.on_load_started()
+    assert progress_widget.value() == 0
+    assert progress_widget.isVisible()
+
+
+# mock tab object
+Tab = namedtuple('Tab', 'progress load_status')
+
+
+@pytest.mark.parametrize('tab, expected_visible', [
+    (Tab(15, webview.LoadStatus.loading), True),
+    (Tab(100, webview.LoadStatus.success), False),
+    (Tab(100, webview.LoadStatus.error), False),
+    (Tab(100, webview.LoadStatus.warn), False),
+    (Tab(100, webview.LoadStatus.none), False),
+])
+def test_tab_changed(progress_widget, tab, expected_visible):
+    """
+    Test that progress widget value and visibility state match expectations,
+    using a dummy Tab object.
+
+    Args:
+        progress_widget: Progress widget that will be tested.
+    """
+    progress_widget.on_tab_changed(tab)
+    assert (progress_widget.value(), progress_widget.isVisible()) == \
+           (tab.progress, expected_visible)