Add regression test for #1815.

tests/test_pilot.py

@@ -0,0 +1,23 @@
+from string import punctuation
+
+from textual import events
+from textual.app import App
+
+KEY_CHARACTERS_TO_TEST = "akTW03" + punctuation.replace("_", "")
+"""Test some "simple" characters (letters + digits) and all punctuation.
+Ignore the underscore because that is an alias to add a pause in the pilot.
+"""
+
+
+async def test_pilot_press_ascii_chars():
+    """Test that the pilot can press most ASCII characters as keys."""
+    keys_pressed = []
+
+    class TestApp(App[None]):
+        def on_key(self, event: events.Key) -> None:
+            keys_pressed.append(event.character)
+
+    async with TestApp().run_test() as pilot:
+        for char in KEY_CHARACTERS_TO_TEST:
+            await pilot.press(char)
+            assert keys_pressed[-1] == char