Snapshotting canonical style property examples

docs/examples/styles/grid.py

@@ -14,5 +14,3 @@ class GridApp(App):
 
 
 app = GridApp(css_path="grid.css")
-if __name__ == "__main__":
-    app.run()

docs/examples/styles/links.py

@@ -13,6 +13,3 @@ class LinksApp(App):
 
 
 app = LinksApp(css_path="links.css")
-
-if __name__ == "__main__":
-    app.run()

tests/snapshot_tests/test_snapshots.py

@@ -1,3 +1,10 @@
+from pathlib import Path
+
+import pytest
+
+
+# --- Layout related stuff ---
+
 def test_grid_layout_basic(snap_compare):
     assert snap_compare("docs/examples/guide/layout/grid_layout1.py")
 
@@ -26,7 +33,34 @@ def test_dock_layout_sidebar(snap_compare):
     assert snap_compare("docs/examples/guide/layout/dock_layout2_sidebar.py")
 
 
+# --- Interacting with widgets ---
+
 def test_checkboxes(snap_compare):
     """Tests checkboxes but also acts a regression test for using
     width: auto in a Horizontal layout context."""
     assert snap_compare("docs/examples/widgets/checkbox.py")
+
+
+def test_input_and_focus(snap_compare):
+    first_field = ["tab"] + list("Darren")  # Focus first input, write "Darren"
+    second_field = ["tab"] + list("Burns")  # Tab focus to second input, write "Burns"
+    assert snap_compare("docs/examples/widgets/input.py", press=first_field + second_field)
+
+
+def test_buttons_render(snap_compare):
+    # Testing button rendering. We press tab to focus the first button too.
+    assert snap_compare("docs/examples/widgets/button.py", press=["tab"])
+
+
+# --- CSS properties ---
+# We have a canonical example for each CSS property that is shown in their docs.
+# If any of these change, something has likely broken, so snapshot each of them.
+
+PATHS = [
+    str(path) for path in Path("docs/examples/styles").iterdir() if path.suffix == ".py"
+]
+
+
+@pytest.mark.parametrize("path", PATHS)
+def test_css_property_snapshot(path, snap_compare):
+    assert snap_compare(path)