Ensure "delete line" keybinding doesnt move cursor in read_only mode …

…in TextArea

src/textual/widgets/_text_area.py

@@ -1950,8 +1950,9 @@ def action_delete_line(self) -> None:
         from_location = (start_row, 0)
         to_location = (end_row + 1, 0)
 
-        self._delete_via_keyboard(from_location, to_location)
-        self.move_cursor_relative(columns=end_column, record_width=False)
+        deletion = self._delete_via_keyboard(from_location, to_location)
+        if deletion is not None:
+            self.move_cursor_relative(columns=end_column, record_width=False)
 
     def action_delete_to_start_of_line(self) -> None:
         """Deletes from the cursor location to the start of the line."""

tests/text_area/test_edit_via_api.py

@@ -5,6 +5,7 @@
 
 Note that more extensive testing for editing is done at the Document level.
 """
+
 import pytest
 
 from textual.app import App, ComposeResult
@@ -521,10 +522,11 @@ async def test_replace_fully_within_selection():
         )
         assert text_area.selected_text == "XX56"
 
+
 async def test_text_setter():
     app = TextAreaApp()
     async with app.run_test():
         text_area = app.query_one(TextArea)
         new_text = "hello\nworld\n"
         text_area.text = new_text
-        assert text_area.text == new_text
+        assert text_area.text == new_text

tests/text_area/test_edit_via_bindings.py

@@ -420,6 +420,37 @@ async def test_delete_word_right_at_end_of_line():
         assert text_area.selection == Selection.cursor((0, 5))
 
 
+@pytest.mark.parametrize(
+    "binding",
+    [
+        "enter",
+        "backspace",
+        "ctrl+u",
+        "ctrl+f",
+        "ctrl+w",
+        "ctrl+k",
+        "ctrl+x",
+        "space",
+        "1",
+        "tab",
+    ],
+)
+async def test_edit_read_only_mode_does_nothing(binding):
+    """Try out various key-presses and bindings and ensure they don't alter
+    the document when read_only=True."""
+    app = TextAreaApp()
+    async with app.run_test() as pilot:
+        text_area = app.query_one(TextArea)
+        text_area.read_only = True
+        selection = Selection.cursor((0, 2))
+        text_area.selection = selection
+
+        await pilot.press(binding)
+
+        assert text_area.text == TEXT
+        assert text_area.selection == selection
+
+
 @pytest.mark.parametrize(
     "selection",
     [

tests/text_area/test_selection_bindings.py

@@ -13,34 +13,48 @@
 
 
 class TextAreaApp(App):
+    def __init__(self, read_only: bool = False):
+        super().__init__()
+        self.read_only = read_only
+
     def compose(self) -> ComposeResult:
-        text_area = TextArea(show_line_numbers=True)
-        text_area.load_text(TEXT)
-        yield text_area
+        yield TextArea(TEXT, show_line_numbers=True, read_only=self.read_only)
+
+
+@pytest.fixture(params=[True, False])
+async def read_only_mode(request):
+    """This parametrised fixture is injected into the app fixture.
+    It means every test that uses the app fixture will run twice - once
+    for read_only=True and once for read_only=False.
+    """
+    return request.param
+
 
+@pytest.fixture
+async def app(read_only_mode: bool):
+    text_area_app = TextAreaApp(read_only_mode)
+    yield text_area_app
 
-async def test_mouse_click():
+
+async def test_mouse_click(app: TextAreaApp):
     """When you click the TextArea, the cursor moves to the expected location."""
-    app = TextAreaApp()
     async with app.run_test() as pilot:
         text_area = app.query_one(TextArea)
         await pilot.click(TextArea, Offset(x=5, y=2))
         assert text_area.selection == Selection.cursor((1, 0))
 
 
-async def test_mouse_click_clamp_from_right():
+async def test_mouse_click_clamp_from_right(app: TextAreaApp):
     """When you click to the right of the document bounds, the cursor is clamped
     to within the document bounds."""
-    app = TextAreaApp()
     async with app.run_test() as pilot:
         text_area = app.query_one(TextArea)
         await pilot.click(TextArea, Offset(x=8, y=20))
         assert text_area.selection == Selection.cursor((4, 0))
 
 
-async def test_mouse_click_gutter_clamp():
+async def test_mouse_click_gutter_clamp(app: TextAreaApp):
     """When you click the gutter, it selects the start of the line."""
-    app = TextAreaApp()
     async with app.run_test() as pilot:
         text_area = app.query_one(TextArea)
         await pilot.click(TextArea, Offset(x=0, y=3))
@@ -66,40 +80,36 @@ async def test_cursor_movement_basic():
         assert text_area.selection == Selection.cursor((0, 0))
 
 
-async def test_cursor_selection_right():
+async def test_cursor_selection_right(app: TextAreaApp):
     """When you press shift+right the selection is updated correctly."""
-    app = TextAreaApp()
     async with app.run_test() as pilot:
         text_area = app.query_one(TextArea)
         await pilot.press(*["shift+right"] * 3)
         assert text_area.selection == Selection((0, 0), (0, 3))
 
 
-async def test_cursor_selection_right_to_previous_line():
+async def test_cursor_selection_right_to_previous_line(app: TextAreaApp):
     """When you press shift+right resulting in the cursor moving to the next line,
     the selection is updated correctly."""
-    app = TextAreaApp()
     async with app.run_test() as pilot:
         text_area = app.query_one(TextArea)
         text_area.selection = Selection.cursor((0, 15))
         await pilot.press(*["shift+right"] * 4)
         assert text_area.selection == Selection((0, 15), (1, 2))
 
 
-async def test_cursor_selection_left():
+async def test_cursor_selection_left(app: TextAreaApp):
     """When you press shift+left the selection is updated correctly."""
-    app = TextAreaApp()
     async with app.run_test() as pilot:
         text_area = app.query_one(TextArea)
         text_area.selection = Selection.cursor((2, 5))
         await pilot.press(*["shift+left"] * 3)
         assert text_area.selection == Selection((2, 5), (2, 2))
 
 
-async def test_cursor_selection_left_to_previous_line():
+async def test_cursor_selection_left_to_previous_line(app: TextAreaApp):
     """When you press shift+left resulting in the cursor moving back to the previous line,
     the selection is updated correctly."""
-    app = TextAreaApp()
     async with app.run_test() as pilot:
         text_area = app.query_one(TextArea)
         text_area.selection = Selection.cursor((2, 2))
@@ -110,9 +120,8 @@ async def test_cursor_selection_left_to_previous_line():
         assert text_area.selection == Selection((2, 2), (1, end_of_previous_line))
 
 
-async def test_cursor_selection_up():
+async def test_cursor_selection_up(app: TextAreaApp):
     """When you press shift+up the selection is updated correctly."""
-    app = TextAreaApp()
     async with app.run_test() as pilot:
         text_area = app.query_one(TextArea)
         text_area.move_cursor((2, 3))
@@ -121,9 +130,8 @@ async def test_cursor_selection_up():
         assert text_area.selection == Selection((2, 3), (1, 3))
 
 
-async def test_cursor_selection_up_when_cursor_on_first_line():
+async def test_cursor_selection_up_when_cursor_on_first_line(app: TextAreaApp):
     """When you press shift+up the on the first line, it selects to the start."""
-    app = TextAreaApp()
     async with app.run_test() as pilot:
         text_area = app.query_one(TextArea)
         text_area.move_cursor((0, 4))
@@ -134,8 +142,7 @@ async def test_cursor_selection_up_when_cursor_on_first_line():
         assert text_area.selection == Selection((0, 4), (0, 0))
 
 
-async def test_cursor_selection_down():
-    app = TextAreaApp()
+async def test_cursor_selection_down(app: TextAreaApp):
     async with app.run_test() as pilot:
         text_area = app.query_one(TextArea)
         text_area.move_cursor((2, 5))
@@ -144,8 +151,7 @@ async def test_cursor_selection_down():
         assert text_area.selection == Selection((2, 5), (3, 5))
 
 
-async def test_cursor_selection_down_when_cursor_on_last_line():
-    app = TextAreaApp()
+async def test_cursor_selection_down_when_cursor_on_last_line(app: TextAreaApp):
     async with app.run_test() as pilot:
         text_area = app.query_one(TextArea)
         text_area.load_text("ABCDEF\nGHIJK")
@@ -157,8 +163,7 @@ async def test_cursor_selection_down_when_cursor_on_last_line():
         assert text_area.selection == Selection((1, 2), (1, 5))
 
 
-async def test_cursor_word_right():
-    app = TextAreaApp()
+async def test_cursor_word_right(app: TextAreaApp):
     async with app.run_test() as pilot:
         text_area = app.query_one(TextArea)
         text_area.load_text("ABC DEF\nGHIJK")
@@ -168,8 +173,7 @@ async def test_cursor_word_right():
         assert text_area.selection == Selection.cursor((0, 3))
 
 
-async def test_cursor_word_right_select():
-    app = TextAreaApp()
+async def test_cursor_word_right_select(app: TextAreaApp):
     async with app.run_test() as pilot:
         text_area = app.query_one(TextArea)
         text_area.load_text("ABC DEF\nGHIJK")
@@ -179,8 +183,7 @@ async def test_cursor_word_right_select():
         assert text_area.selection == Selection((0, 0), (0, 3))
 
 
-async def test_cursor_word_left():
-    app = TextAreaApp()
+async def test_cursor_word_left(app: TextAreaApp):
     async with app.run_test() as pilot:
         text_area = app.query_one(TextArea)
         text_area.load_text("ABC DEF\nGHIJK")
@@ -191,8 +194,7 @@ async def test_cursor_word_left():
         assert text_area.selection == Selection.cursor((0, 4))
 
 
-async def test_cursor_word_left_select():
-    app = TextAreaApp()
+async def test_cursor_word_left_select(app: TextAreaApp):
     async with app.run_test() as pilot:
         text_area = app.query_one(TextArea)
         text_area.load_text("ABC DEF\nGHIJK")
@@ -204,9 +206,8 @@ async def test_cursor_word_left_select():
 
 
 @pytest.mark.parametrize("key", ["end", "ctrl+e"])
-async def test_cursor_to_line_end(key):
+async def test_cursor_to_line_end(key, app: TextAreaApp):
     """You can use the keyboard to jump the cursor to the end of the current line."""
-    app = TextAreaApp()
     async with app.run_test() as pilot:
         text_area = app.query_one(TextArea)
         text_area.selection = Selection.cursor((2, 2))
@@ -217,9 +218,8 @@ async def test_cursor_to_line_end(key):
 
 
 @pytest.mark.parametrize("key", ["home", "ctrl+a"])
-async def test_cursor_to_line_home_basic_behaviour(key):
+async def test_cursor_to_line_home_basic_behaviour(key, app: TextAreaApp):
     """You can use the keyboard to jump the cursor to the start of the current line."""
-    app = TextAreaApp()
     async with app.run_test() as pilot:
         text_area = app.query_one(TextArea)
         text_area.selection = Selection.cursor((2, 2))
@@ -239,11 +239,12 @@ async def test_cursor_to_line_home_basic_behaviour(key):
         ((0, 15), (0, 4)),
     ],
 )
-async def test_cursor_line_home_smart_home(cursor_start, cursor_destination):
+async def test_cursor_line_home_smart_home(
+    cursor_start, cursor_destination, app: TextAreaApp
+):
     """If the line begins with whitespace, pressing home firstly goes
     to the start of the (non-whitespace) content. Pressing it again takes you to column
     0. If you press it again, it goes back to the first non-whitespace column."""
-    app = TextAreaApp()
     async with app.run_test() as pilot:
         text_area = app.query_one(TextArea)
         text_area.load_text("    hello world")
@@ -252,9 +253,8 @@ async def test_cursor_line_home_smart_home(cursor_start, cursor_destination):
         assert text_area.selection == Selection.cursor(cursor_destination)
 
 
-async def test_cursor_page_down():
+async def test_cursor_page_down(app: TextAreaApp):
     """Pagedown moves the cursor down 1 page, retaining column index."""
-    app = TextAreaApp()
     async with app.run_test() as pilot:
         text_area = app.query_one(TextArea)
         text_area.load_text("XXX\n" * 200)
@@ -266,9 +266,8 @@ async def test_cursor_page_down():
         )
 
 
-async def test_cursor_page_up():
+async def test_cursor_page_up(app: TextAreaApp):
     """Pageup moves the cursor up 1 page, retaining column index."""
-    app = TextAreaApp()
     async with app.run_test() as pilot:
         text_area = app.query_one(TextArea)
         text_area.load_text("XXX\n" * 200)
@@ -280,10 +279,9 @@ async def test_cursor_page_up():
         )
 
 
-async def test_cursor_vertical_movement_visual_alignment_snapping():
+async def test_cursor_vertical_movement_visual_alignment_snapping(app: TextAreaApp):
     """When you move the cursor vertically, it should stay vertically
     aligned even when double-width characters are used."""
-    app = TextAreaApp()
     async with app.run_test() as pilot:
         text_area = app.query_one(TextArea)
         text_area.text = "こんにちは\n012345"
@@ -301,8 +299,7 @@ async def test_cursor_vertical_movement_visual_alignment_snapping():
         assert text_area.selection == Selection.cursor((1, 3))
 
 
-async def test_select_line_binding():
-    app = TextAreaApp()
+async def test_select_line_binding(app: TextAreaApp):
     async with app.run_test() as pilot:
         text_area = app.query_one(TextArea)
         text_area.move_cursor((2, 2))
@@ -312,8 +309,7 @@ async def test_select_line_binding():
         assert text_area.selection == Selection((2, 0), (2, 56))
 
 
-async def test_select_all_binding():
-    app = TextAreaApp()
+async def test_select_all_binding(app: TextAreaApp):
     async with app.run_test() as pilot:
         text_area = app.query_one(TextArea)