Cover a few more cases when testing #4301

Co-authored-by: TomJGooding <[email protected]>

tests/text_area/test_issue_4301.py

@@ -1,12 +1,13 @@
+from itertools import product
+
+import pytest
+
 from textual.app import App, ComposeResult
 from textual.widgets import TextArea
 from textual.widgets.text_area import Selection
 
 TEST_TEXT = "\n".join(f"01234567890 - {n}" for n in range(10))
-TEST_SELECTION = Selection((2, 5), (0, 5))
 TEST_SELECTED_TEXT = "567890 - 0\n01234567890 - 1\n01234"
-TEST_REPLACEMENT = "A"
-TEST_RESULT_TEXT = TEST_TEXT.replace(TEST_SELECTED_TEXT, TEST_REPLACEMENT)
 
 
 class TextAreaApp(App[None]):
@@ -15,14 +16,23 @@ def compose(self) -> ComposeResult:
         yield TextArea(TEST_TEXT)
 
 
-async def test_issue_4301_reproduction() -> None:
+@pytest.mark.parametrize(
+    "selection, edit",
+    product(
+        [Selection((0, 5), (2, 5)), Selection((2, 5), (0, 5))],
+        ["A", "delete", "backspace"],
+    ),
+)
+async def test_issue_4301_reproduction(selection: Selection, edit: str) -> None:
+    """Test https://github.com/Textualize/textual/issues/4301"""
 
     async with (app := TextAreaApp()).run_test() as pilot:
         assert app.query_one(TextArea).text == TEST_TEXT
-        app.query_one(TextArea).selection = TEST_SELECTION
+        app.query_one(TextArea).selection = selection
         assert app.query_one(TextArea).selected_text == TEST_SELECTED_TEXT
-        await pilot.press("A")
-        assert app.query_one(TextArea).text == TEST_RESULT_TEXT
+        await pilot.press(edit)
         await pilot.press("ctrl+z")
         assert app.query_one(TextArea).text == TEST_TEXT
+        # Note that the real test here is that the following code doesn't
+        # result in a crash; everything above should really be a given.
         await pilot.press(*(["down"] * 10))