tests: conftest/ui/ui_tools: refactor: Extract key params as fixture.

Added a fixture, navigation_key_expected_key_pair, in `conftest.py`
to generate test cases for keypress tests related to navigation. This
helps in reducing code duplication through the sharing of the common
fixture among different navigation tests.

Tests amended for navigation keypresses in View and HelpView to
leverage the fixture.

Author: preetmishra

tests/conftest.py

@@ -4,6 +4,7 @@
 
 import pytest
 
+from zulipterminal.config.keys import keys_for_command
 from zulipterminal.helper import initial_index as helper_initial_index
 from zulipterminal.ui_tools.boxes import MessageBox
 from zulipterminal.ui_tools.buttons import (
@@ -756,3 +757,27 @@ def classified_unread_counts():
             99: 1
         }
     }
+
+# --------------- UI Fixtures -----------------------------------------
+
+
+@pytest.fixture(params=[
+        (key, expected_key)
+        for keys, expected_key in [
+            (keys_for_command('GO_UP'), 'up'),
+            (keys_for_command('GO_DOWN'), 'down'),
+            (keys_for_command('SCROLL_UP'), 'page up'),
+            (keys_for_command('SCROLL_DOWN'), 'page down'),
+            (keys_for_command('GO_TO_BOTTOM'), 'end'),
+        ]
+        for key in keys
+    ],
+    ids=lambda param: 'key:{}-expected_key:{}'.format(*param)
+)
+def navigation_key_expected_key_pair(request):
+    """
+    Fixture to generate pairs of navigation keys with their respective
+    expected key.
+    The expected key is the one which is passed to the super `keypress` calls.
+    """
+    return request.param

tests/ui/test_ui.py

@@ -181,19 +181,9 @@ def test_show_right_panel(self, mocker, view,
         else:
             view.body.options.assert_not_called()
 
-    @pytest.mark.parametrize('key, expected_key', [
-        (key, expected_key)
-        for keys, expected_key in [
-            (keys_for_command('GO_UP'), 'up'),
-            (keys_for_command('GO_DOWN'), 'down'),
-            (keys_for_command('SCROLL_UP'), 'page up'),
-            (keys_for_command('SCROLL_DOWN'), 'page down'),
-            (keys_for_command('GO_TO_BOTTOM'), 'end'),
-        ]
-        for key in keys
-    ])
     def test_keypress_normal_mode_navigation(self, view, mocker,
-                                             key, expected_key):
+                                             navigation_key_expected_key_pair):
+        key, expected_key = navigation_key_expected_key_pair
         view.users_view = mocker.Mock()
         view.body = mocker.Mock()
         view.user_search = mocker.Mock()

tests/ui/test_ui_tools.py

@@ -1112,18 +1112,9 @@ def test_keypress_GO_BACK(self, key):
         self.help_view.keypress(size, key)
         assert self.controller.exit_popup.called
 
-    @pytest.mark.parametrize('key, expected_key', [
-        (key, expected_key)
-        for keys, expected_key in [
-            (keys_for_command('GO_UP'), 'up'),
-            (keys_for_command('GO_DOWN'), 'down'),
-            (keys_for_command('SCROLL_UP'), 'page up'),
-            (keys_for_command('SCROLL_DOWN'), 'page down'),
-            (keys_for_command('GO_TO_BOTTOM'), 'end'),
-        ]
-        for key in keys
-    ])
-    def test_keypress_navigation(self, mocker, key, expected_key):
+    def test_keypress_navigation(self, mocker,
+                                 navigation_key_expected_key_pair):
+        key, expected_key = navigation_key_expected_key_pair
         size = (200, 20)
         super_keypress = mocker.patch(VIEWS + '.urwid.ListBox.keypress')
         self.help_view.keypress(size, key)