views: Migrate mouse_event to use keys_for_command.

The migration helps in using keys_for_command in the test as well.

Tests amended for Streams/UsersView and added for TopicsView.

Author: preetmishra

tests/ui/test_ui_tools.py

@@ -461,8 +461,8 @@ def test_keypress_navigation(self, mocker, stream_view,
         super_view.assert_called_once_with(size, expected_key)
 
     @pytest.mark.parametrize('event, button, key', [
-        ('mouse press', 4, 'up'),
-        ('mouse press', 5, 'down'),
+        ('mouse press', 4, keys_for_command('GO_UP').pop()),
+        ('mouse press', 5, keys_for_command('GO_DOWN').pop()),
     ])
     def test_mouse_event(self, mocker, stream_view, event, button, key):
         size = (200, 20)
@@ -652,6 +652,16 @@ def test_keypress_navigation(self, mocker, topic_view,
         topic_view.keypress(size, key)
         super_view.assert_called_once_with(size, expected_key)
 
+    @pytest.mark.parametrize('event, button, key', [
+        ('mouse press', 4, keys_for_command('GO_UP').pop()),
+        ('mouse press', 5, keys_for_command('GO_DOWN').pop()),
+    ])
+    def test_mouse_event(self, mocker, topic_view, event, button, key):
+        mocker.patch.object(topic_view, 'keypress')
+        size = (200, 20)
+        topic_view.mouse_event(size, event, button, 1, 1, 'WIDGET')
+        topic_view.keypress.assert_called_with(size, key)
+
 
 class TestUsersView:
 
@@ -669,8 +679,8 @@ def test_keypress_navigation(self, mocker, user_view,
         super_view.assert_called_once_with(size, expected_key)
 
     @pytest.mark.parametrize('event, button, key', [
-        ('mouse press', 4, 'up'),
-        ('mouse press', 5, 'down'),
+        ('mouse press', 4, keys_for_command('GO_UP').pop()),
+        ('mouse press', 5, keys_for_command('GO_DOWN').pop()),
     ])
     def test_mouse_event(self, mocker, user_view, event, button, key):
         mocker.patch.object(user_view, 'keypress')

zulipterminal/ui_tools/views.py

@@ -284,10 +284,10 @@ def mouse_event(self, size: urwid_Size, event: str, button: int, col: int,
                     row: int, focus: bool) -> bool:
         if event == 'mouse press':
             if button == 4:
-                self.keypress(size, 'up')
+                self.keypress(size, keys_for_command('GO_UP').pop())
                 return True
             elif button == 5:
-                self.keypress(size, 'down')
+                self.keypress(size, keys_for_command('GO_DOWN').pop())
                 return True
         return super().mouse_event(size, event, button, col, row, focus)
 
@@ -377,10 +377,10 @@ def mouse_event(self, size: urwid_Size, event: str, button: int, col: int,
                     row: int, focus: bool) -> bool:
         if event == 'mouse press':
             if button == 4:
-                self.keypress(size, 'up')
+                self.keypress(size, keys_for_command('GO_UP').pop())
                 return True
             elif button == 5:
-                self.keypress(size, 'down')
+                self.keypress(size, keys_for_command('GO_DOWN').pop())
                 return True
         return super().mouse_event(size, event, button, col, row, focus)
 
@@ -422,11 +422,11 @@ def mouse_event(self, size: urwid_Size, event: str, button: int, col: int,
         if event == 'mouse press':
             if button == 4:
                 for _ in range(5):
-                    self.keypress(size, 'up')
+                    self.keypress(size, keys_for_command('GO_UP').pop())
                 return True
             elif button == 5:
                 for _ in range(5):
-                    self.keypress(size, 'down')
+                    self.keypress(size, keys_for_command('GO_DOWN').pop())
         return super().mouse_event(size, event, button, col, row, focus)
 
     def keypress(self, size: urwid_Size, key: str) -> Optional[str]: