fix _gather_elements in User class to only return visible elements (#…

…4057)

When using `User` simulation methods such as `should_see`,
`should_not_see`, or `find`, the `visible` state of the element is
ignored. This can result in unexpected behavior. For example, if an
element is invisible, but `should_see` or `find` is used, the visibility
state is disregarded.

Consider a scenario where an element is created and set to be invisible,
but becomes visible at a later point. In the current version, testing
with `should_see` would always pass because the 'visible' state is
ignored. Ideally, `should_see` should raise an error if the element is
not visible.

This behavior is similar for `find` and `should_not_see`, where the
visibility state is not taken into account during the test.

This is fixed by only returning visible elements in `_gather_elements`.
Additionally for better debugging the `__str__` method of `Element`
includes the `visible` state of the element.

---------

Co-authored-by: Moritz Erlacher <[email protected]>

nicegui/element.py

@@ -519,6 +519,8 @@ def shorten(content: Any, length: int = 20) -> str:
             for key, value in self._props.items()
             if not key.startswith('_') and key not in IGNORED_PROPS and value
         ]
+        if not self.visible:
+            additions.append(f'visible={self.visible}')
         if additions:
             result += f' [{", ".join(additions)}]'
 

nicegui/testing/user.py

@@ -191,20 +191,23 @@ def current_layout(self) -> Element:
         """Return the root layout element of the current page."""
         return self._client.layout
 
-    def _gather_elements(self,
-                         target: Union[str, Type[T], None] = None,
-                         kind: Optional[Type[T]] = None,
-                         marker: Union[str, List[str], None] = None,
-                         content: Union[str, List[str], None] = None,
-                         ) -> Set[T]:
+    def _gather_elements(
+        self,
+        target: Union[str, Type[T], None] = None,
+        kind: Optional[Type[T]] = None,
+        marker: Union[str, List[str], None] = None,
+        content: Union[str, List[str], None] = None,
+    ) -> Set[T]:
         if target is None:
             if kind is None:
-                return set(ElementFilter(marker=marker, content=content))  # type: ignore
-            return set(ElementFilter(kind=kind, marker=marker, content=content))
+                elements = set(ElementFilter(marker=marker, content=content))
+            else:
+                elements = set(ElementFilter(kind=kind, marker=marker, content=content))
         elif isinstance(target, str):
-            return set(ElementFilter(marker=target)).union(ElementFilter(content=target))  # type: ignore
+            elements = set(ElementFilter(marker=target)).union(ElementFilter(content=target))
         else:
-            return set(ElementFilter(kind=target))
+            elements = set(ElementFilter(kind=target))
+        return {e for e in elements if e.visible}  # type: ignore
 
     def _build_error_message(self,
                              target: Union[str, Type[T], None] = None,

tests/test_user_simulation.py

@@ -419,3 +419,52 @@ async def test_trigger_autocomplete(user: User) -> None:
     await user.should_not_see('apple')
     user.find('fruit').type('a').trigger('keydown.tab')
     await user.should_see('apple')
+
+async def test_should_see_on_invisible_element(user: User) -> None:
+    lable = ui.label('Hello')
+    lable.visible = False
+
+    await user.open('/')
+    with pytest.raises(AssertionError):
+        await user.should_see('Hello')
+    lable.visible = True
+    await user.should_see('Hello')
+
+
+async def test_should_not_see_on_invisible_element(user: User) -> None:
+    lable = ui.label('Hello')
+    lable.visible = True
+
+    await user.open('/')
+    with pytest.raises(AssertionError):
+        await user.should_not_see('Hello')
+    lable.visible = False
+    await user.should_not_see('Hello')
+
+
+async def test_find_on_invisible_element(user: User) -> None:
+    button = ui.button('click me', on_click=lambda: ui.label('clicked'))
+    button.visible = False
+
+    await user.open('/')
+    with pytest.raises(AssertionError):
+        user.find('click me').click()
+    button.visible = True
+    user.find('click me').click()
+    await user.should_see('clicked')
+
+async def test_page_to_sting_output_with_hidden_elements(user: User) -> None:
+    ui.label("Hello")
+    hidden_label = ui.label("Hidden Label")
+    hidden_label.visible = False
+
+    await user.open('/')
+    output = str(user.current_layout)
+    assert output == '''
+q-layout
+ q-page-container
+  q-page
+   div
+    Label [text=Hello]
+    Label [text=Hidden Label, visible=False]
+'''.strip()