Adding upstream version 0.12.0.

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

tests/snapshot_tests/snapshot_apps/datatable_hot_reloading.py

@@ -0,0 +1,58 @@
+from pathlib import Path
+
+from textual.app import App, ComposeResult
+from textual_fastdatatable import ArrowBackend, DataTable
+
+CSS_PATH = (Path(__file__) / "../datatable_hot_reloading.tcss").resolve()
+
+# Write some CSS to the file before the app loads.
+# Then, the test will clear all the CSS to see if the
+# hot reloading applies the changes correctly.
+CSS_PATH.write_text(
+    """\
+DataTable > .datatable--cursor {
+    background: purple;
+}
+
+DataTable > .datatable--fixed {
+    background: red;
+}
+
+DataTable > .datatable--fixed-cursor {
+    background: blue;
+}
+
+DataTable > .datatable--header {
+    background: yellow;
+}
+
+DataTable > .datatable--odd-row {
+    background: pink;
+}
+
+DataTable > .datatable--even-row {
+    background: brown;
+}
+"""
+)
+
+
+class DataTableHotReloadingApp(App[None]):
+    CSS_PATH = CSS_PATH
+
+    def compose(self) -> ComposeResult:
+        data = {
+            # orig test set A width=10, we fake it with spaces
+            "A         ": ["one", "three", "five"],
+            "B": ["two", "four", "six"],
+        }
+        backend = ArrowBackend.from_pydict(data)
+        yield DataTable(backend, zebra_stripes=True, cursor_type="row", fixed_columns=1)
+
+    def on_mount(self) -> None:
+        self.query_one(DataTable)
+
+
+if __name__ == "__main__":
+    app = DataTableHotReloadingApp()
+    app.run()