enforcing explicit passing of path to improve readability.

tests/test_pages.py

@@ -8,7 +8,7 @@ async def test_title(user: User):
     def page():
         ui.label('some content')
 
-    user.open()
+    user.open('/')
     user.should_see('My Custom Title')
 
 
@@ -28,7 +28,7 @@ async def test_auto_index_page_with_link_to_subpage(user: User):
     def page():
         ui.label('the subpage')
 
-    user.open()
+    user.open('/')
     user.click('link to subpage')
     user.should_see('the subpage')
 
@@ -40,13 +40,13 @@ async def test_link_to_page_by_passing_function(user: User):
 
     ui.link('link to subpage', page)
 
-    user.open()
+    user.open('/')
     user.click('link to subpage')
     user.should_see('the subpage')
 
 
 async def test_creating_new_page_after_startup(user: User):
-    user.open()
+    user.open('/')
 
     @ui.page('/late_page')
     def page():

tests/user.py

@@ -27,7 +27,7 @@ class User():
         nicegui_globals.server.should_exit = True
         self.thread.join()
 
-    def open(self, path: str = '/') -> None:
+    def open(self, path: str) -> None:
         if self.thread is None:
             self.start_server()
         start = time.time()