#791 add pytest

tests/test_label.py

@@ -8,3 +8,10 @@ def test_hello_world(screen: Screen):
 
     screen.open('/')
     screen.should_contain('Hello, world')
+
+
+def test_text_0(screen: Screen):
+    ui.label(0)
+
+    screen.open('/')
+    screen.should_contain('0')