Adding upstream version 4.0.4.

Signed-off-by: Daniel Baumann <daniel@debian.org>

tests/snapshots/test_cursor_tracking.py

@@ -0,0 +1,81 @@
+from __future__ import annotations
+
+from textual.app import App, ComposeResult
+from textual.containers import Center, VerticalScroll
+from textual.pilot import Pilot
+from textual.widgets import Input
+from textual_autocomplete import AutoComplete
+
+
+class CursorTracking(App[None]):
+    CSS = """
+    #scrollable {
+        overflow: scroll scroll;
+        scrollbar-color: red;
+        Center {
+            background: $accent;
+            height: 100;
+            width: 100;
+            align-vertical: middle;
+        }
+        Input {
+            width: 24;
+        }
+    }
+    """
+
+    def compose(self) -> ComposeResult:
+        with VerticalScroll(id="scrollable", can_focus=False):
+            with Center():
+                input = Input(placeholder="Type here...")
+                input.cursor_blink = False
+                yield input
+
+        yield AutoComplete(
+            target=input,
+            candidates=["foo", "bar", "baz", "qux", "boop"],
+        )
+
+
+def test_dropdown_tracks_terminal_cursor_when_parent_scrolls(snap_compare):
+    """We type, the dropdown appears, then we scroll the parent container so that the position of the input
+    and the dropdown changes on screen. The dropdown should remain aligned to the Input widget."""
+
+    async def run_before(pilot: Pilot[None]) -> None:
+        await pilot.press("b")
+        scrollable = pilot.app.query_one("#scrollable")
+        scrollable.scroll_relative(x=5, y=5, animate=False, force=True)
+        await pilot.pause()
+
+    assert snap_compare(CursorTracking(), run_before=run_before)
+
+
+def test_dropdown_tracks_input_cursor_and_cursor_prefix_as_search_string(snap_compare):
+    """The completions should be based on the text between the start of the input and the cursor location.
+
+    In this example, we type "ba", then move the cursor back one cell so that the search string is "b",
+    meaning the completions should be "bar", "baz", and "boop".
+    """
+
+    async def run_before(pilot: Pilot[None]) -> None:
+        await pilot.press(*"ba")  # Type "ba"
+        await pilot.press("left")  # Move the cursor back one cell
+
+    assert snap_compare(CursorTracking(), run_before=run_before)
+
+
+def test_dropdown_tracks_input_cursor_on_click_and_cursor_prefix_search_string(
+    snap_compare,
+):
+    """The completions should be based on the text between the start of the input and the cursor location.
+
+    In this example, we type "ba", then move the cursor back one cell by clicking, so that the search string is "b",
+    meaning the completions should be "bar", "baz", and "boop".
+    """
+
+    async def run_before(pilot: Pilot[None]) -> None:
+        await pilot.press(*"ba")  # Type "ba"
+        input_widget = pilot.app.query_one(Input)
+        await pilot.click(input_widget, offset=(4, 1))  # Click on the "a"
+
+    assert snap_compare(CursorTracking(), run_before=run_before)