Fix the page up/down bindings for OptionList (#3024)

* Fix the page up/down bindings for OptionList

I'd had page_up and page_down bound when the actual names of the bindings
are pageup and pagedown. This has always worked by sheer fluke because of
where OptionList inherits from and by the coincidence of the action names.

In other words: this commit has no substantive impact; but it does fix code
that wasn't helpful and also makes the documentation more correct.

* Correct the page up/down keys in the option list movement tests

Turns out the pilot lets you press keys that don't actually exist. Who
knew?!?

Author: davep

src/textual/widgets/_option_list.py

@@ -130,8 +130,8 @@ class OptionList(ScrollView, can_focus=True):
         Binding("end", "last", "Last", show=False),
         Binding("enter", "select", "Select", show=False),
         Binding("home", "first", "First", show=False),
-        Binding("page_down", "page_down", "Page Down", show=False),
-        Binding("page_up", "page_up", "Page Up", show=False),
+        Binding("pagedown", "page_down", "Page Down", show=False),
+        Binding("pageup", "page_up", "Page Up", show=False),
         Binding("up", "cursor_up", "Up", show=False),
     ]
     """
@@ -141,8 +141,8 @@ class OptionList(ScrollView, can_focus=True):
     | end | Move the highlight to the last option. |
     | enter | Select the current option. |
     | home | Move the highlight to the first option. |
-    | page_down | Move the highlight down a page of options. |
-    | page_up | Move the highlight up a page of options. |
+    | pagedown | Move the highlight down a page of options. |
+    | pageup | Move the highlight up a page of options. |
     | up | Move the highlight up. |
     """
 

tests/option_list/test_option_list_movement.py

@@ -33,7 +33,7 @@ async def test_cleared_movement_does_nothing() -> None:
         option_list = pilot.app.query_one(OptionList)
         option_list.clear_options()
         assert option_list.highlighted is None
-        await pilot.press("tab", "down", "up", "page_down", "page_up", "home", "end")
+        await pilot.press("tab", "down", "up", "pagedown", "pageup", "home", "end")
         assert option_list.highlighted is None
 
 
@@ -90,7 +90,7 @@ async def test_move_home() -> None:
 async def test_page_down_from_start_short_list() -> None:
     """Doing a page down from the start of a short list should move to the end."""
     async with OptionListApp().run_test() as pilot:
-        await pilot.press("tab", "page_down")
+        await pilot.press("tab", "pagedown")
         assert pilot.app.query_one(OptionList).highlighted == 5
 
 
@@ -101,7 +101,7 @@ async def test_page_up_from_end_short_list() -> None:
         assert option_list.highlighted == 0
         option_list.highlighted = 5
         assert option_list.highlighted == 5
-        await pilot.press("tab", "page_up")
+        await pilot.press("tab", "pageup")
         assert option_list.highlighted == 0
 
 
@@ -112,14 +112,14 @@ async def test_page_down_from_end_short_list() -> None:
         assert option_list.highlighted == 0
         option_list.highlighted = 5
         assert option_list.highlighted == 5
-        await pilot.press("tab", "page_down")
+        await pilot.press("tab", "pagedown")
         assert option_list.highlighted == 5
 
 
 async def test_page_up_from_start_short_list() -> None:
     """Doing a page up from the start of a short list go nowhere."""
     async with OptionListApp().run_test() as pilot:
-        await pilot.press("tab", "page_up")
+        await pilot.press("tab", "pageup")
         assert pilot.app.query_one(OptionList).highlighted == 0
 
 
@@ -135,7 +135,7 @@ async def test_empty_list_movement() -> None:
     async with EmptyOptionListApp().run_test() as pilot:
         option_list = pilot.app.query_one(OptionList)
         await pilot.press("tab")
-        for movement in ("up", "down", "home", "end", "page_up", "page_down"):
+        for movement in ("up", "down", "home", "end", "pageup", "pagedown"):
             await pilot.press(movement)
             assert option_list.highlighted is None
 
@@ -147,8 +147,8 @@ async def test_no_highlight_movement() -> None:
         ("down", 0),
         ("home", 0),
         ("end", 99),
-        ("page_up", 0),
-        ("page_down", 99),
+        ("pageup", 0),
+        ("pagedown", 99),
     ):
         async with EmptyOptionListApp().run_test() as pilot:
             option_list = pilot.app.query_one(OptionList)