added demo to snapshots

CHANGELOG.md

@@ -25,6 +25,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 
 - Type selectors can now contain numbers https://github.com/Textualize/textual/issues/1253
 - Fixed visibility not affecting children https://github.com/Textualize/textual/issues/1313
+- Fixed issue with auto width/height and relative children https://github.com/Textualize/textual/issues/1319
 
 ## [0.5.0] - 2022-11-20
 

tests/snapshot_tests/test_snapshots.py

@@ -156,3 +156,8 @@ def test_columns_height(snap_compare):
 
 def test_key_display(snap_compare):
     assert snap_compare(SNAPSHOT_APPS_DIR / "key_display.py")
+
+
+def test_demo(snap_compare):
+    """Test the demo app (python -m textual)"""
+    assert snap_compare(Path("../../src/textual/demo.py"))