Add unit test of ui.separator

Author: python-and-novella

tests/test_separator.py

@@ -0,0 +1,25 @@
+from nicegui import ui
+from nicegui.testing import Screen
+
+
+def test_separator(screen: Screen):
+    @ui.page('/column')
+    def index():
+        with ui.column():
+            ui.button('1')
+            ui.separator()
+            ui.button('2')
+    @ui.page('/row')
+    def index():
+        with ui.row():
+            ui.button('1')
+            ui.separator().props('vertical')
+            ui.button('2')
+
+
+    screen.open('/column')
+    assert screen.find_by_tag('hr').value_of_css_property('width') == '100%'
+
+    screen.wait(0.5)
+    screen.open('/row')
+    assert screen.find_by_tag('hr').value_of_css_property('width') == '1px'