Class HookCatcher

src/py/reactpy/reactpy/testing/common.py:101–152

Utility for capturing a LifeCycleHook from a component Example: .. code-block:: hooks = HookCatcher(index_by_kwarg="thing") @reactpy.component @hooks.capture def MyComponent(thing): ... ... # render the comp

class HookCatcher:
    """Utility for capturing a LifeCycleHook from a component

    Example:
        .. code-block::

            hooks = HookCatcher(index_by_kwarg="thing")

            @reactpy.component
            @hooks.capture
            def MyComponent(thing):
                ...

            ...  # render the component

            # grab the last render of where MyComponent(thing='something')
            hooks.index["something"]
            # or grab the hook from the component's last render
            hooks.latest

        After the first render of ``MyComponent`` the ``HookCatcher`` will have
        captured the component's ``LifeCycleHook``.
    """

    latest: LifeCycleHook

    def __init__(self, index_by_kwarg: str | None = None):
        self.index_by_kwarg = index_by_kwarg
        self.index: dict[Any, LifeCycleHook] = {}

    def capture(self, render_function: Callable[..., Any]) -> Callable[..., Any]:
        """Decorator for capturing a ``LifeCycleHook`` on each render of a component"""

        # The render function holds a reference to `self` and, via the `LifeCycleHook`,
        # the component. Some tests check whether components are garbage collected, thus
        # we must use a `ref` here to ensure these checks pass once the catcher itself
        # has been collected.
        self_ref = ref(self)

        @wraps(render_function)
        def wrapper(*args: Any, **kwargs: Any) -> Any:
            self = self_ref()
            if self is None:
                raise RuntimeError("Hook catcher has been garbage collected")

            hook = current_hook()
            if self.index_by_kwarg is not None:
                self.index[kwargs[self.index_by_kwarg]] = hook
            self.latest = hook
            return render_function(*args, **kwargs)

        return wrapper


class StaticEventHandler: