reflex/tests/test_app.py

from __future__ import annotations

import functools
import io
import json
import os.path
import re
import unittest.mock
import uuid
from contextlib import nullcontext as does_not_raise
from pathlib import Path
from typing import Generator, List, Tuple, Type
from unittest.mock import AsyncMock

import pytest
import sqlmodel
from fastapi import FastAPI, UploadFile
from starlette_admin.auth import AuthProvider
from starlette_admin.contrib.sqla.admin import Admin
from starlette_admin.contrib.sqla.view import ModelView

import reflex as rx
from reflex import AdminDash, constants
from reflex.app import (
    App,
    ComponentCallable,
    OverlayFragment,
    default_overlay_component,
    process,
    upload,
)
from reflex.components import Component
from reflex.components.base.fragment import Fragment
from reflex.components.core.cond import Cond
from reflex.components.radix.themes.typography.text import Text
from reflex.event import Event
from reflex.ivars.base import immutable_computed_var
from reflex.middleware import HydrateMiddleware
from reflex.model import Model
from reflex.state import (
    BaseState,
    OnLoadInternalState,
    RouterData,
    State,
    StateManagerDisk,
    StateManagerMemory,
    StateManagerRedis,
    StateUpdate,
    _substate_key,
)
from reflex.style import Style
from reflex.utils import exceptions, format

from .conftest import chdir
from .states import (
    ChildFileUploadState,
    FileStateBase1,
    FileUploadState,
    GenState,
    GrandChildFileUploadState,
)


class EmptyState(BaseState):
    """An empty state."""

    pass


@pytest.fixture
def index_page() -> ComponentCallable:
    """An index page.

    Returns:
        The index page.
    """

    def index():
        return rx.box("Index")

    return index


@pytest.fixture
def about_page() -> ComponentCallable:
    """An about page.

    Returns:
        The about page.
    """

    def about():
        return rx.box("About")

    return about


class ATestState(BaseState):
    """A simple state for testing."""

    var: int


@pytest.fixture()
def test_state() -> Type[BaseState]:
    """A default state.

    Returns:
        A default state.
    """
    return ATestState


@pytest.fixture()
def redundant_test_state() -> Type[BaseState]:
    """A default state.

    Returns:
        A default state.
    """

    class RedundantTestState(BaseState):
        var: int

    return RedundantTestState


@pytest.fixture(scope="session")
def test_model() -> Type[Model]:
    """A default model.

    Returns:
        A default model.
    """

    class TestModel(Model, table=True):  # type: ignore
        pass

    return TestModel


@pytest.fixture(scope="session")
def test_model_auth() -> Type[Model]:
    """A default model.

    Returns:
        A default model.
    """

    class TestModelAuth(Model, table=True):  # type: ignore
        """A test model with auth."""

        pass

    return TestModelAuth


@pytest.fixture()
def test_get_engine():
    """A default database engine.

    Returns:
        A default database engine.
    """
    enable_admin = True
    url = "sqlite:///test.db"
    return sqlmodel.create_engine(
        url,
        echo=False,
        connect_args={"check_same_thread": False} if enable_admin else {},
    )


@pytest.fixture()
def test_custom_auth_admin() -> Type[AuthProvider]:
    """A default auth provider.

    Returns:
        A default default auth provider.
    """

    class TestAuthProvider(AuthProvider):
        """A test auth provider."""

        login_path: str = "/login"
        logout_path: str = "/logout"

        def login(self):
            """Login."""
            pass

        def is_authenticated(self):
            """Is authenticated."""
            pass

        def get_admin_user(self):
            """Get admin user."""
            pass

        def logout(self):
            """Logout."""
            pass

    return TestAuthProvider


def test_default_app(app: App):
    """Test creating an app with no args.

    Args:
        app: The app to test.
    """
    assert app.middleware == [HydrateMiddleware()]
    assert app.style == Style()
    assert app.admin_dash is None


def test_multiple_states_error(monkeypatch, test_state, redundant_test_state):
    """Test that an error is thrown when multiple classes subclass rx.BaseState.

    Args:
        monkeypatch: Pytest monkeypatch object.
        test_state: A test state subclassing rx.BaseState.
        redundant_test_state: Another test state subclassing rx.BaseState.
    """
    monkeypatch.delenv(constants.PYTEST_CURRENT_TEST)
    with pytest.raises(ValueError):
        App()


def test_add_page_default_route(app: App, index_page, about_page):
    """Test adding a page to an app.

    Args:
        app: The app to test.
        index_page: The index page.
        about_page: The about page.
    """
    assert app.pages == {}
    app.add_page(index_page)
    assert app.pages.keys() == {"index"}
    app.add_page(about_page)
    assert app.pages.keys() == {"index", "about"}


def test_add_page_set_route(app: App, index_page, windows_platform: bool):
    """Test adding a page to an app.

    Args:
        app: The app to test.
        index_page: The index page.
        windows_platform: Whether the system is windows.
    """
    route = "test" if windows_platform else "/test"
    assert app.pages == {}
    app.add_page(index_page, route=route)
    assert app.pages.keys() == {"test"}


def test_add_page_set_route_dynamic(index_page, windows_platform: bool):
    """Test adding a page with dynamic route variable to an app.

    Args:
        index_page: The index page.
        windows_platform: Whether the system is windows.
    """
    app = App(state=EmptyState)
    assert app.state is not None
    route = "/test/[dynamic]"
    assert app.pages == {}
    app.add_page(index_page, route=route)
    assert app.pages.keys() == {"test/[dynamic]"}
    assert "dynamic" in app.state.computed_vars
    assert app.state.computed_vars["dynamic"]._deps(objclass=EmptyState) == {
        constants.ROUTER
    }
    assert constants.ROUTER in app.state()._computed_var_dependencies


def test_add_page_set_route_nested(app: App, index_page, windows_platform: bool):
    """Test adding a page to an app.

    Args:
        app: The app to test.
        index_page: The index page.
        windows_platform: Whether the system is windows.
    """
    route = "test\\nested" if windows_platform else "/test/nested"
    assert app.pages == {}
    app.add_page(index_page, route=route)
    assert app.pages.keys() == {route.strip(os.path.sep)}


def test_add_page_invalid_api_route(app: App, index_page):
    """Test adding a page with an invalid route to an app.

    Args:
        app: The app to test.
        index_page: The index page.
    """
    with pytest.raises(ValueError):
        app.add_page(index_page, route="api")
    with pytest.raises(ValueError):
        app.add_page(index_page, route="/api")
    with pytest.raises(ValueError):
        app.add_page(index_page, route="/api/")
    with pytest.raises(ValueError):
        app.add_page(index_page, route="api/foo")
    with pytest.raises(ValueError):
        app.add_page(index_page, route="/api/foo")
    # These should be fine
    app.add_page(index_page, route="api2")
    app.add_page(index_page, route="/foo/api")


def page1():
    return rx.fragment()


def page2():
    return rx.fragment()


def index():
    return rx.fragment()


@pytest.mark.parametrize(
    "first_page,second_page, route",
    [
        (lambda: rx.fragment(), lambda: rx.fragment(rx.text("second")), "/"),
        (rx.fragment(rx.text("first")), rx.fragment(rx.text("second")), "/page1"),
        (
            lambda: rx.fragment(rx.text("first")),
            rx.fragment(rx.text("second")),
            "page3",
        ),
        (page1, page2, "page1"),
        (index, index, None),
        (page1, page1, None),
    ],
)
def test_add_duplicate_page_route_error(app, first_page, second_page, route):
    app.add_page(first_page, route=route)
    with pytest.raises(ValueError):
        app.add_page(second_page, route="/" + route.strip("/") if route else None)


def test_initialize_with_admin_dashboard(test_model):
    """Test setting the admin dashboard of an app.

    Args:
        test_model: The default model.
    """
    app = App(admin_dash=AdminDash(models=[test_model]))
    assert app.admin_dash is not None
    assert len(app.admin_dash.models) > 0
    assert app.admin_dash.models[0] == test_model


def test_initialize_with_custom_admin_dashboard(
    test_get_engine,
    test_custom_auth_admin,
    test_model_auth,
):
    """Test setting the custom admin dashboard of an app.

    Args:
        test_get_engine: The default database engine.
        test_model_auth: The default model for an auth admin dashboard.
        test_custom_auth_admin: The custom auth provider.
    """
    custom_auth_provider = test_custom_auth_admin()
    custom_admin = Admin(engine=test_get_engine, auth_provider=custom_auth_provider)
    app = App(admin_dash=AdminDash(models=[test_model_auth], admin=custom_admin))
    assert app.admin_dash is not None
    assert app.admin_dash.admin is not None
    assert len(app.admin_dash.models) > 0
    assert app.admin_dash.models[0] == test_model_auth
    assert app.admin_dash.admin.auth_provider == custom_auth_provider


def test_initialize_admin_dashboard_with_view_overrides(test_model):
    """Test setting the admin dashboard of an app with view class overridden.

    Args:
        test_model: The default model.
    """

    class TestModelView(ModelView):
        pass

    app = App(
        admin_dash=AdminDash(
            models=[test_model], view_overrides={test_model: TestModelView}
        )
    )
    assert app.admin_dash is not None
    assert app.admin_dash.models == [test_model]
    assert app.admin_dash.view_overrides[test_model] == TestModelView


@pytest.mark.asyncio
async def test_initialize_with_state(test_state: Type[ATestState], token: str):
    """Test setting the state of an app.

    Args:
        test_state: The default state.
        token: a Token.
    """
    app = App(state=test_state)
    assert app.state == test_state

    # Get a state for a given token.
    state = await app.state_manager.get_state(_substate_key(token, test_state))
    assert isinstance(state, test_state)
    assert state.var == 0  # type: ignore

    if isinstance(app.state_manager, StateManagerRedis):
        await app.state_manager.close()


@pytest.mark.asyncio
async def test_set_and_get_state(test_state):
    """Test setting and getting the state of an app with different tokens.

    Args:
        test_state: The default state.
    """
    app = App(state=test_state)

    # Create two tokens.
    token1 = str(uuid.uuid4()) + f"_{test_state.get_full_name()}"
    token2 = str(uuid.uuid4()) + f"_{test_state.get_full_name()}"

    # Get the default state for each token.
    state1 = await app.state_manager.get_state(token1)
    state2 = await app.state_manager.get_state(token2)
    assert state1.var == 0  # type: ignore
    assert state2.var == 0  # type: ignore

    # Set the vars to different values.
    state1.var = 1
    state2.var = 2
    await app.state_manager.set_state(token1, state1)
    await app.state_manager.set_state(token2, state2)

    # Get the states again and check the values.
    state1 = await app.state_manager.get_state(token1)
    state2 = await app.state_manager.get_state(token2)
    assert state1.var == 1  # type: ignore
    assert state2.var == 2  # type: ignore

    if isinstance(app.state_manager, StateManagerRedis):
        await app.state_manager.close()


@pytest.mark.asyncio
async def test_dynamic_var_event(test_state: Type[ATestState], token: str):
    """Test that the default handler of a dynamic generated var
    works as expected.

    Args:
        test_state: State Fixture.
        token: a Token.
    """
    state = test_state()  # type: ignore
    state.add_var("int_val", int, 0)
    result = await state._process(
        Event(
            token=token,
            name=f"{test_state.get_name()}.set_int_val",
            router_data={"pathname": "/", "query": {}},
            payload={"value": 50},
        )
    ).__anext__()
    assert result.delta == {test_state.get_name(): {"int_val": 50}}


@pytest.mark.asyncio
@pytest.mark.parametrize(
    "event_tuples",
    [
        pytest.param(
            [
                (
                    "make_friend",
                    {"plain_friends": ["Tommy", "another-fd"]},
                ),
                (
                    "change_first_friend",
                    {"plain_friends": ["Jenny", "another-fd"]},
                ),
            ],
            id="append then __setitem__",
        ),
        pytest.param(
            [
                (
                    "unfriend_first_friend",
                    {"plain_friends": []},
                ),
                (
                    "make_friend",
                    {"plain_friends": ["another-fd"]},
                ),
            ],
            id="delitem then append",
        ),
        pytest.param(
            [
                (
                    "make_friends_with_colleagues",
                    {"plain_friends": ["Tommy", "Peter", "Jimmy"]},
                ),
                (
                    "remove_tommy",
                    {"plain_friends": ["Peter", "Jimmy"]},
                ),
                (
                    "remove_last_friend",
                    {"plain_friends": ["Peter"]},
                ),
                (
                    "unfriend_all_friends",
                    {"plain_friends": []},
                ),
            ],
            id="extend, remove, pop, clear",
        ),
        pytest.param(
            [
                (
                    "add_jimmy_to_second_group",
                    {"friends_in_nested_list": [["Tommy"], ["Jenny", "Jimmy"]]},
                ),
                (
                    "remove_first_person_from_first_group",
                    {"friends_in_nested_list": [[], ["Jenny", "Jimmy"]]},
                ),
                (
                    "remove_first_group",
                    {"friends_in_nested_list": [["Jenny", "Jimmy"]]},
                ),
            ],
            id="nested list",
        ),
        pytest.param(
            [
                (
                    "add_jimmy_to_tommy_friends",
                    {"friends_in_dict": {"Tommy": ["Jenny", "Jimmy"]}},
                ),
                (
                    "remove_jenny_from_tommy",
                    {"friends_in_dict": {"Tommy": ["Jimmy"]}},
                ),
                (
                    "tommy_has_no_fds",
                    {"friends_in_dict": {"Tommy": []}},
                ),
            ],
            id="list in dict",
        ),
    ],
)
async def test_list_mutation_detection__plain_list(
    event_tuples: List[Tuple[str, List[str]]],
    list_mutation_state: State,
    token: str,
):
    """Test list mutation detection
    when reassignment is not explicitly included in the logic.

    Args:
        event_tuples: From parametrization.
        list_mutation_state: A state with list mutation features.
        token: a Token.
    """
    for event_name, expected_delta in event_tuples:
        result = await list_mutation_state._process(
            Event(
                token=token,
                name=f"{list_mutation_state.get_name()}.{event_name}",
                router_data={"pathname": "/", "query": {}},
                payload={},
            )
        ).__anext__()

        # prefix keys in expected_delta with the state name
        expected_delta = {list_mutation_state.get_name(): expected_delta}
        assert result.delta == expected_delta


@pytest.mark.asyncio
@pytest.mark.parametrize(
    "event_tuples",
    [
        pytest.param(
            [
                (
                    "add_age",
                    {"details": {"name": "Tommy", "age": 20}},
                ),
                (
                    "change_name",
                    {"details": {"name": "Jenny", "age": 20}},
                ),
                (
                    "remove_last_detail",
                    {"details": {"name": "Jenny"}},
                ),
            ],
            id="update then __setitem__",
        ),
        pytest.param(
            [
                (
                    "clear_details",
                    {"details": {}},
                ),
                (
                    "add_age",
                    {"details": {"age": 20}},
                ),
            ],
            id="delitem then update",
        ),
        pytest.param(
            [
                (
                    "add_age",
                    {"details": {"name": "Tommy", "age": 20}},
                ),
                (
                    "remove_name",
                    {"details": {"age": 20}},
                ),
                (
                    "pop_out_age",
                    {"details": {}},
                ),
            ],
            id="add, remove, pop",
        ),
        pytest.param(
            [
                (
                    "remove_home_address",
                    {"address": [{}, {"work": "work address"}]},
                ),
                (
                    "add_street_to_home_address",
                    {
                        "address": [
                            {"street": "street address"},
                            {"work": "work address"},
                        ]
                    },
                ),
            ],
            id="dict in list",
        ),
        pytest.param(
            [
                (
                    "change_friend_name",
                    {
                        "friend_in_nested_dict": {
                            "name": "Nikhil",
                            "friend": {"name": "Tommy"},
                        }
                    },
                ),
                (
                    "add_friend_age",
                    {
                        "friend_in_nested_dict": {
                            "name": "Nikhil",
                            "friend": {"name": "Tommy", "age": 30},
                        }
                    },
                ),
                (
                    "remove_friend",
                    {"friend_in_nested_dict": {"name": "Nikhil"}},
                ),
            ],
            id="nested dict",
        ),
    ],
)
async def test_dict_mutation_detection__plain_list(
    event_tuples: List[Tuple[str, List[str]]],
    dict_mutation_state: State,
    token: str,
):
    """Test dict mutation detection
    when reassignment is not explicitly included in the logic.

    Args:
        event_tuples: From parametrization.
        dict_mutation_state: A state with dict mutation features.
        token: a Token.
    """
    for event_name, expected_delta in event_tuples:
        result = await dict_mutation_state._process(
            Event(
                token=token,
                name=f"{dict_mutation_state.get_name()}.{event_name}",
                router_data={"pathname": "/", "query": {}},
                payload={},
            )
        ).__anext__()

        # prefix keys in expected_delta with the state name
        expected_delta = {dict_mutation_state.get_name(): expected_delta}

        assert result.delta == expected_delta


@pytest.mark.asyncio
@pytest.mark.parametrize(
    ("state", "delta"),
    [
        (
            FileUploadState,
            {
                FileUploadState.get_full_name(): {
                    "img_list": ["image1.jpg", "image2.jpg"]
                }
            },
        ),
        (
            ChildFileUploadState,
            {
                ChildFileUploadState.get_full_name(): {
                    "img_list": ["image1.jpg", "image2.jpg"]
                }
            },
        ),
        (
            GrandChildFileUploadState,
            {
                GrandChildFileUploadState.get_full_name(): {
                    "img_list": ["image1.jpg", "image2.jpg"]
                }
            },
        ),
    ],
)
async def test_upload_file(tmp_path, state, delta, token: str, mocker):
    """Test that file upload works correctly.

    Args:
        tmp_path: Temporary path.
        state: The state class.
        delta: Expected delta
        token: a Token.
        mocker: pytest mocker object.
    """
    mocker.patch(
        "reflex.state.State.class_subclasses",
        {state if state is FileUploadState else FileStateBase1},
    )
    state._tmp_path = tmp_path
    # The App state must be the "root" of the state tree
    app = App(state=State)
    app.event_namespace.emit = AsyncMock()  # type: ignore
    current_state = await app.state_manager.get_state(_substate_key(token, state))
    data = b"This is binary data"

    # Create a binary IO object and write data to it
    bio = io.BytesIO()
    bio.write(data)

    request_mock = unittest.mock.Mock()
    request_mock.headers = {
        "reflex-client-token": token,
        "reflex-event-handler": f"{state.get_full_name()}.multi_handle_upload",
    }

    file1 = UploadFile(
        filename=f"image1.jpg",
        file=bio,
    )
    file2 = UploadFile(
        filename=f"image2.jpg",
        file=bio,
    )
    upload_fn = upload(app)
    streaming_response = await upload_fn(request_mock, [file1, file2])
    async for state_update in streaming_response.body_iterator:
        assert (
            state_update
            == StateUpdate(delta=delta, events=[], final=True).json() + "\n"
        )

    current_state = await app.state_manager.get_state(_substate_key(token, state))
    state_dict = current_state.dict()[state.get_full_name()]
    assert state_dict["img_list"] == [
        "image1.jpg",
        "image2.jpg",
    ]

    if isinstance(app.state_manager, StateManagerRedis):
        await app.state_manager.close()


@pytest.mark.asyncio
@pytest.mark.parametrize(
    "state",
    [FileUploadState, ChildFileUploadState, GrandChildFileUploadState],
)
async def test_upload_file_without_annotation(state, tmp_path, token):
    """Test that an error is thrown when there's no param annotated with rx.UploadFile or List[UploadFile].

    Args:
        state: The state class.
        tmp_path: Temporary path.
        token: a Token.
    """
    state._tmp_path = tmp_path
    app = App(state=State)

    request_mock = unittest.mock.Mock()
    request_mock.headers = {
        "reflex-client-token": token,
        "reflex-event-handler": f"{state.get_full_name()}.handle_upload2",
    }
    file_mock = unittest.mock.Mock(filename="image1.jpg")
    fn = upload(app)
    with pytest.raises(ValueError) as err:
        await fn(request_mock, [file_mock])
    assert (
        err.value.args[0]
        == f"`{state.get_full_name()}.handle_upload2` handler should have a parameter annotated as List[rx.UploadFile]"
    )

    if isinstance(app.state_manager, StateManagerRedis):
        await app.state_manager.close()


@pytest.mark.asyncio
@pytest.mark.parametrize(
    "state",
    [FileUploadState, ChildFileUploadState, GrandChildFileUploadState],
)
async def test_upload_file_background(state, tmp_path, token):
    """Test that an error is thrown handler is a background task.

    Args:
        state: The state class.
        tmp_path: Temporary path.
        token: a Token.
    """
    state._tmp_path = tmp_path
    app = App(state=State)

    request_mock = unittest.mock.Mock()
    request_mock.headers = {
        "reflex-client-token": token,
        "reflex-event-handler": f"{state.get_full_name()}.bg_upload",
    }
    file_mock = unittest.mock.Mock(filename="image1.jpg")
    fn = upload(app)
    with pytest.raises(TypeError) as err:
        await fn(request_mock, [file_mock])
    assert (
        err.value.args[0]
        == f"@rx.background is not supported for upload handler `{state.get_full_name()}.bg_upload`."
    )

    if isinstance(app.state_manager, StateManagerRedis):
        await app.state_manager.close()


class DynamicState(BaseState):
    """State class for testing dynamic route var.

    This is defined at module level because event handlers cannot be addressed
    correctly when the class is defined as a local.

    There are several counters:
      * loaded: counts how many times `on_load` was triggered by the hydrate middleware
      * counter: counts how many times `on_counter` was triggered by a non-navigational event
          -> these events should NOT trigger reload or recalculation of router_data dependent vars
      * side_effect_counter: counts how many times a computed var was
        recalculated when the dynamic route var was dirty
    """

    is_hydrated: bool = False
    loaded: int = 0
    counter: int = 0

    # side_effect_counter: int = 0

    def on_load(self):
        """Event handler for page on_load, should trigger for all navigation events."""
        self.loaded = self.loaded + 1

    def on_counter(self):
        """Increment the counter var."""
        self.counter = self.counter + 1

    @immutable_computed_var(cache=True)
    def comp_dynamic(self) -> str:
        """A computed var that depends on the dynamic var.

        Returns:
            same as self.dynamic
        """
        # self.side_effect_counter = self.side_effect_counter + 1
        return self.dynamic

    on_load_internal = OnLoadInternalState.on_load_internal.fn


def test_dynamic_arg_shadow(
    index_page: ComponentCallable,
    windows_platform: bool,
    token: str,
    app_module_mock: unittest.mock.Mock,
    mocker,
):
    """Create app with dynamic route var and try to add a page with a dynamic arg that shadows a state var.

    Args:
        index_page: The index page.
        windows_platform: Whether the system is windows.
        token: a Token.
        app_module_mock: Mocked app module.
        mocker: pytest mocker object.
    """
    arg_name = "counter"
    route = f"/test/[{arg_name}]"
    app = app_module_mock.app = App(state=DynamicState)
    assert app.state is not None
    with pytest.raises(NameError):
        app.add_page(index_page, route=route, on_load=DynamicState.on_load)  # type: ignore


def test_multiple_dynamic_args(
    index_page: ComponentCallable,
    windows_platform: bool,
    token: str,
    app_module_mock: unittest.mock.Mock,
    mocker,
):
    """Create app with multiple dynamic route vars with the same name.

    Args:
        index_page: The index page.
        windows_platform: Whether the system is windows.
        token: a Token.
        app_module_mock: Mocked app module.
        mocker: pytest mocker object.
    """
    arg_name = "my_arg"
    route = f"/test/[{arg_name}]"
    route2 = f"/test2/[{arg_name}]"
    app = app_module_mock.app = App(state=EmptyState)
    app.add_page(index_page, route=route)
    app.add_page(index_page, route=route2)


@pytest.mark.asyncio
async def test_dynamic_route_var_route_change_completed_on_load(
    index_page: ComponentCallable,
    windows_platform: bool,
    token: str,
    app_module_mock: unittest.mock.Mock,
    mocker,
):
    """Create app with dynamic route var, and simulate navigation.

    on_load should fire, allowing any additional vars to be updated before the
    initial page hydrate.

    Args:
        index_page: The index page.
        windows_platform: Whether the system is windows.
        token: a Token.
        app_module_mock: Mocked app module.
        mocker: pytest mocker object.
    """
    arg_name = "dynamic"
    route = f"/test/[{arg_name}]"
    app = app_module_mock.app = App(state=DynamicState)
    assert app.state is not None
    assert arg_name not in app.state.vars
    app.add_page(index_page, route=route, on_load=DynamicState.on_load)  # type: ignore
    assert arg_name in app.state.vars
    assert arg_name in app.state.computed_vars
    assert app.state.computed_vars[arg_name]._deps(objclass=DynamicState) == {
        constants.ROUTER
    }
    assert constants.ROUTER in app.state()._computed_var_dependencies

    substate_token = _substate_key(token, DynamicState)
    sid = "mock_sid"
    client_ip = "127.0.0.1"
    state = await app.state_manager.get_state(substate_token)
    assert state.dynamic == ""
    exp_vals = ["foo", "foobar", "baz"]

    def _event(name, val, **kwargs):
        return Event(
            token=kwargs.pop("token", token),
            name=name,
            router_data=kwargs.pop(
                "router_data", {"pathname": route, "query": {arg_name: val}}
            ),
            payload=kwargs.pop("payload", {}),
            **kwargs,
        )

    def _dynamic_state_event(name, val, **kwargs):
        return _event(
            name=format.format_event_handler(getattr(DynamicState, name)),  # type: ignore
            val=val,
            **kwargs,
        )

    prev_exp_val = ""
    for exp_index, exp_val in enumerate(exp_vals):
        on_load_internal = _event(
            name=f"{state.get_full_name()}.{constants.CompileVars.ON_LOAD_INTERNAL.rpartition('.')[2]}",
            val=exp_val,
        )
        exp_router_data = {
            "headers": {},
            "ip": client_ip,
            "sid": sid,
            "token": token,
            **on_load_internal.router_data,
        }
        exp_router = RouterData(exp_router_data)
        process_coro = process(
            app,
            event=on_load_internal,
            sid=sid,
            headers={},
            client_ip=client_ip,
        )
        update = await process_coro.__anext__()
        # route change (on_load_internal) triggers: [call on_load events, call set_is_hydrated(True)]
        assert update == StateUpdate(
            delta={
                state.get_name(): {
                    arg_name: exp_val,
                    f"comp_{arg_name}": exp_val,
                    constants.CompileVars.IS_HYDRATED: False,
                    # "side_effect_counter": exp_index,
                    "router": exp_router,
                }
            },
            events=[
                _dynamic_state_event(
                    name="on_load",
                    val=exp_val,
                ),
                _event(
                    name=f"{State.get_name()}.set_is_hydrated",
                    payload={"value": True},
                    val=exp_val,
                    router_data={},
                ),
            ],
        )
        if isinstance(app.state_manager, StateManagerRedis):
            # When redis is used, the state is not updated until the processing is complete
            state = await app.state_manager.get_state(substate_token)
            assert state.dynamic == prev_exp_val

        # complete the processing
        with pytest.raises(StopAsyncIteration):
            await process_coro.__anext__()

        # check that router data was written to the state_manager store
        state = await app.state_manager.get_state(substate_token)
        assert state.dynamic == exp_val

        process_coro = process(
            app,
            event=_dynamic_state_event(name="on_load", val=exp_val),
            sid=sid,
            headers={},
            client_ip=client_ip,
        )
        on_load_update = await process_coro.__anext__()
        assert on_load_update == StateUpdate(
            delta={
                state.get_name(): {
                    "loaded": exp_index + 1,
                },
            },
            events=[],
        )
        # complete the processing
        with pytest.raises(StopAsyncIteration):
            await process_coro.__anext__()
        process_coro = process(
            app,
            event=_dynamic_state_event(
                name="set_is_hydrated", payload={"value": True}, val=exp_val
            ),
            sid=sid,
            headers={},
            client_ip=client_ip,
        )
        on_set_is_hydrated_update = await process_coro.__anext__()
        assert on_set_is_hydrated_update == StateUpdate(
            delta={
                state.get_name(): {
                    "is_hydrated": True,
                },
            },
            events=[],
        )
        # complete the processing
        with pytest.raises(StopAsyncIteration):
            await process_coro.__anext__()

        # a simple state update event should NOT trigger on_load or route var side effects
        process_coro = process(
            app,
            event=_dynamic_state_event(name="on_counter", val=exp_val),
            sid=sid,
            headers={},
            client_ip=client_ip,
        )
        update = await process_coro.__anext__()
        assert update == StateUpdate(
            delta={
                state.get_name(): {
                    "counter": exp_index + 1,
                }
            },
            events=[],
        )
        # complete the processing
        with pytest.raises(StopAsyncIteration):
            await process_coro.__anext__()

        prev_exp_val = exp_val
    state = await app.state_manager.get_state(substate_token)
    assert state.loaded == len(exp_vals)
    assert state.counter == len(exp_vals)
    # print(f"Expected {exp_vals} rendering side effects, got {state.side_effect_counter}")
    # assert state.side_effect_counter == len(exp_vals)

    if isinstance(app.state_manager, StateManagerRedis):
        await app.state_manager.close()


@pytest.mark.asyncio
async def test_process_events(mocker, token: str):
    """Test that an event is processed properly and that it is postprocessed
    n+1 times. Also check that the processing flag of the last stateupdate is set to
    False.

    Args:
        mocker: mocker object.
        token: a Token.
    """
    router_data = {
        "pathname": "/",
        "query": {},
        "token": token,
        "sid": "mock_sid",
        "headers": {},
        "ip": "127.0.0.1",
    }
    app = App(state=GenState)
    mocker.patch.object(app, "_postprocess", AsyncMock())
    event = Event(
        token=token,
        name=f"{GenState.get_name()}.go",
        payload={"c": 5},
        router_data=router_data,
    )

    async for _update in process(app, event, "mock_sid", {}, "127.0.0.1"):
        pass

    assert (await app.state_manager.get_state(event.substate_token)).value == 5
    assert app._postprocess.call_count == 6

    if isinstance(app.state_manager, StateManagerRedis):
        await app.state_manager.close()


@pytest.mark.parametrize(
    ("state", "overlay_component", "exp_page_child"),
    [
        (None, default_overlay_component, None),
        (None, None, None),
        (None, Text.create("foo"), Text),
        (State, default_overlay_component, Fragment),
        (State, None, None),
        (State, Text.create("foo"), Text),
        (State, lambda: Text.create("foo"), Text),
    ],
)
def test_overlay_component(
    state: State | None,
    overlay_component: Component | ComponentCallable | None,
    exp_page_child: Type[Component] | None,
):
    """Test that the overlay component is set correctly.

    Args:
        state: The state class to pass to App.
        overlay_component: The overlay_component to pass to App.
        exp_page_child: The type of the expected child in the page fragment.
    """
    app = App(state=state, overlay_component=overlay_component)
    app._setup_overlay_component()
    if exp_page_child is None:
        assert app.overlay_component is None
    elif isinstance(exp_page_child, OverlayFragment):
        assert app.overlay_component is not None
        generated_component = app._generate_component(app.overlay_component)  # type: ignore
        assert isinstance(generated_component, OverlayFragment)
        assert isinstance(
            generated_component.children[0],
            Cond,  # ConnectionModal is a Cond under the hood
        )
    else:
        assert app.overlay_component is not None
        assert isinstance(
            app._generate_component(app.overlay_component),  # type: ignore
            exp_page_child,
        )

    app.add_page(rx.box("Index"), route="/test")
    # overlay components are wrapped during compile only
    app._setup_overlay_component()
    page = app.pages["test"]

    if exp_page_child is not None:
        assert len(page.children) == 3
        children_types = (type(child) for child in page.children)
        assert exp_page_child in children_types
    else:
        assert len(page.children) == 2


@pytest.fixture
def compilable_app(tmp_path) -> Generator[tuple[App, Path], None, None]:
    """Fixture for an app that can be compiled.

    Args:
        tmp_path: Temporary path.

    Yields:
        Tuple containing (app instance, Path to ".web" directory)

        The working directory is set to the app dir (parent of .web),
        allowing app.compile() to be called.
    """
    app_path = tmp_path / "app"
    web_dir = app_path / ".web"
    web_dir.mkdir(parents=True)
    (web_dir / constants.PackageJson.PATH).touch()
    app = App(theme=None)
    app._get_frontend_packages = unittest.mock.Mock()
    with chdir(app_path):
        yield app, web_dir


def test_app_wrap_compile_theme(compilable_app: tuple[App, Path]):
    """Test that the radix theme component wraps the app.

    Args:
        compilable_app: compilable_app fixture.
    """
    app, web_dir = compilable_app
    app.theme = rx.theme(accent_color="plum")
    app._compile()
    app_js_contents = (web_dir / "pages" / "_app.js").read_text()
    app_js_lines = [
        line.strip() for line in app_js_contents.splitlines() if line.strip()
    ]
    assert (
        "function AppWrap({children}) {"
        "return ("
        "<RadixThemesColorModeProvider>"
        "<RadixThemesTheme accentColor={\"plum\"} css={{...theme.styles.global[':root'], ...theme.styles.global.body}}>"
        "<Fragment>"
        "{children}"
        "</Fragment>"
        "</RadixThemesTheme>"
        "</RadixThemesColorModeProvider>"
        ")"
        "}"
    ) in "".join(app_js_lines)


def test_app_wrap_priority(compilable_app: tuple[App, Path]):
    """Test that the app wrap components are wrapped in the correct order.

    Args:
        compilable_app: compilable_app fixture.
    """
    app, web_dir = compilable_app

    class Fragment1(Component):
        tag = "Fragment1"

        def _get_app_wrap_components(self) -> dict[tuple[int, str], Component]:
            return {(99, "Box"): rx.box()}

    class Fragment2(Component):
        tag = "Fragment2"

        def _get_app_wrap_components(self) -> dict[tuple[int, str], Component]:
            return {(50, "Text"): rx.text()}

    class Fragment3(Component):
        tag = "Fragment3"

        def _get_app_wrap_components(self) -> dict[tuple[int, str], Component]:
            return {(10, "Fragment2"): Fragment2.create()}

    def page():
        return Fragment1.create(Fragment3.create())

    app.add_page(page)
    app._compile()
    app_js_contents = (web_dir / "pages" / "_app.js").read_text()
    app_js_lines = [
        line.strip() for line in app_js_contents.splitlines() if line.strip()
    ]
    assert (
        "function AppWrap({children}) {"
        "return ("
        "<RadixThemesBox>"
        '<RadixThemesText as={"p"}>'
        "<RadixThemesColorModeProvider>"
        "<Fragment2>"
        "<Fragment>"
        "{children}"
        "</Fragment>"
        "</Fragment2>"
        "</RadixThemesColorModeProvider>"
        "</RadixThemesText>"
        "</RadixThemesBox>"
        ")"
        "}"
    ) in "".join(app_js_lines)


def test_app_state_determination():
    """Test that the stateless status of an app is determined correctly."""
    a1 = App()
    assert a1.state is None

    # No state, no router, no event handlers.
    a1.add_page(rx.box("Index"), route="/")
    assert a1.state is None

    # Add a page with `on_load` enables state.
    a1.add_page(rx.box("About"), route="/about", on_load=rx.console_log(""))
    assert a1.state is not None

    a2 = App()
    assert a2.state is None

    # Referencing a state Var enables state.
    a2.add_page(rx.box(rx.text(GenState.value)), route="/")
    assert a2.state is not None

    a3 = App()
    assert a3.state is None

    # Referencing router enables state.
    a3.add_page(rx.box(rx.text(State.router.page.full_path)), route="/")
    assert a3.state is not None

    a4 = App()
    assert a4.state is None

    a4.add_page(rx.box(rx.button("Click", on_click=rx.console_log(""))), route="/")
    assert a4.state is None

    a4.add_page(
        rx.box(rx.button("Click", on_click=DynamicState.on_counter)), route="/page2"
    )
    assert a4.state is not None


# for coverage
def test_raise_on_connect_error():
    """Test that the connect_error function is called."""
    with pytest.raises(ValueError):
        App(connect_error_component="Foo")


def test_raise_on_state():
    """Test that the state is set."""
    # state kwargs is deprecated, we just make sure the app is created anyway.
    _app = App(state=State)
    assert _app.state is not None
    assert issubclass(_app.state, State)


def test_call_app():
    """Test that the app can be called."""
    app = App()
    api = app()
    assert isinstance(api, FastAPI)


def test_app_with_optional_endpoints():
    from reflex.components.core.upload import Upload

    app = App()
    Upload.is_used = True
    app._add_optional_endpoints()
    # TODO: verify the availability of the endpoints in app.api


def test_app_state_manager():
    app = App()
    with pytest.raises(ValueError):
        app.state_manager
    app._enable_state()
    assert app.state_manager is not None
    assert isinstance(
        app.state_manager, (StateManagerMemory, StateManagerDisk, StateManagerRedis)
    )


def test_generate_component():
    def index():
        return rx.box("Index")

    def index_mismatch():
        return rx.match(
            1,
            (1, rx.box("Index")),
            (2, "About"),
            "Bar",
        )

    comp = App._generate_component(index)  # type: ignore
    assert isinstance(comp, Component)

    with pytest.raises(exceptions.MatchTypeError):
        App._generate_component(index_mismatch)  # type: ignore


def test_add_page_component_returning_tuple():
    """Test that a component or render method returning a
    tuple is unpacked in a Fragment.
    """
    app = App()

    def index():
        return rx.text("first"), rx.text("second")

    def page2():
        return (rx.text("third"),)

    app.add_page(index)  # type: ignore
    app.add_page(page2)  # type: ignore

    assert isinstance((fragment_wrapper := app.pages["index"].children[0]), Fragment)
    assert isinstance((first_text := fragment_wrapper.children[0]), Text)
    assert str(first_text.children[0].contents) == '"first"'  # type: ignore
    assert isinstance((second_text := fragment_wrapper.children[1]), Text)
    assert str(second_text.children[0].contents) == '"second"'  # type: ignore

    # Test page with trailing comma.
    assert isinstance(
        (page2_fragment_wrapper := app.pages["page2"].children[0]), Fragment
    )
    assert isinstance((third_text := page2_fragment_wrapper.children[0]), Text)
    assert str(third_text.children[0].contents) == '"third"'  # type: ignore


@pytest.mark.parametrize("export", (True, False))
def test_app_with_transpile_packages(compilable_app: tuple[App, Path], export: bool):
    class C1(rx.Component):
        library = "foo@1.2.3"
        tag = "Foo"
        transpile_packages: List[str] = ["foo"]

    class C2(rx.Component):
        library = "bar@4.5.6"
        tag = "Bar"
        transpile_packages: List[str] = ["bar@4.5.6"]

    class C3(rx.NoSSRComponent):
        library = "baz@7.8.10"
        tag = "Baz"
        transpile_packages: List[str] = ["baz@7.8.9"]

    class C4(rx.NoSSRComponent):
        library = "quuc@2.3.4"
        tag = "Quuc"
        transpile_packages: List[str] = ["quuc"]

    class C5(rx.Component):
        library = "quuc"
        tag = "Quuc"

    app, web_dir = compilable_app
    page = Fragment.create(
        C1.create(), C2.create(), C3.create(), C4.create(), C5.create()
    )
    app.add_page(page, route="/")
    app._compile(export=export)

    next_config = (web_dir / "next.config.js").read_text()
    transpile_packages_match = re.search(r"transpilePackages: (\[.*?\])", next_config)
    transpile_packages_json = transpile_packages_match.group(1)  # type: ignore
    transpile_packages = sorted(json.loads(transpile_packages_json))

    assert transpile_packages == [
        "bar",
        "foo",
        "quuc",
    ]

    if export:
        assert 'output: "export"' in next_config
        assert f'distDir: "{constants.Dirs.STATIC}"' in next_config
    else:
        assert 'output: "export"' not in next_config
        assert f'distDir: "{constants.Dirs.STATIC}"' not in next_config


def test_app_with_valid_var_dependencies(compilable_app: tuple[App, Path]):
    app, _ = compilable_app

    class ValidDepState(BaseState):
        base: int = 0
        _backend: int = 0

        @immutable_computed_var(cache=True)
        def foo(self) -> str:
            return "foo"

        @immutable_computed_var(deps=["_backend", "base", foo], cache=True)
        def bar(self) -> str:
            return "bar"

    app.state = ValidDepState
    app._compile()


def test_app_with_invalid_var_dependencies(compilable_app: tuple[App, Path]):
    app, _ = compilable_app

    class InvalidDepState(BaseState):
        @immutable_computed_var(deps=["foolksjdf"], cache=True)
        def bar(self) -> str:
            return "bar"

    app.state = InvalidDepState
    with pytest.raises(exceptions.VarDependencyError):
        app._compile()


# Test custom exception handlers


def valid_custom_handler(exception: Exception, logger: str = "test"):
    print("Custom Backend Exception")
    print(exception)


def custom_exception_handler_with_wrong_arg_order(
    logger: str,
    exception: Exception,  # Should be first
):
    print("Custom Backend Exception")
    print(exception)


def custom_exception_handler_with_wrong_argspec(
    exception: str,  # Should be Exception
):
    print("Custom Backend Exception")
    print(exception)


class DummyExceptionHandler:
    """Dummy exception handler class."""

    def handle(self, exception: Exception):
        """Handle the exception.

        Args:
            exception: The exception.

        """
        print("Custom Backend Exception")
        print(exception)


custom_exception_handlers = {
    "lambda": lambda exception: print("Custom Exception Handler", exception),
    "wrong_argspec": custom_exception_handler_with_wrong_argspec,
    "wrong_arg_order": custom_exception_handler_with_wrong_arg_order,
    "valid": valid_custom_handler,
    "partial": functools.partial(valid_custom_handler, logger="test"),
    "method": DummyExceptionHandler().handle,
}


@pytest.mark.parametrize(
    "handler_fn, expected",
    [
        pytest.param(
            custom_exception_handlers["partial"],
            pytest.raises(ValueError),
            id="partial",
        ),
        pytest.param(
            custom_exception_handlers["lambda"],
            pytest.raises(ValueError),
            id="lambda",
        ),
        pytest.param(
            custom_exception_handlers["wrong_argspec"],
            pytest.raises(ValueError),
            id="wrong_argspec",
        ),
        pytest.param(
            custom_exception_handlers["wrong_arg_order"],
            pytest.raises(ValueError),
            id="wrong_arg_order",
        ),
        pytest.param(
            custom_exception_handlers["valid"],
            does_not_raise(),
            id="valid_handler",
        ),
        pytest.param(
            custom_exception_handlers["method"],
            does_not_raise(),
            id="valid_class_method",
        ),
    ],
)
def test_frontend_exception_handler_validation(handler_fn, expected):
    """Test that the custom frontend exception handler is properly validated.

    Args:
        handler_fn: The handler function.
        expected: The expected result.

    """
    with expected:
        rx.App(frontend_exception_handler=handler_fn)._validate_exception_handlers()


def backend_exception_handler_with_wrong_return_type(exception: Exception) -> int:
    """Custom backend exception handler with wrong return type.

    Args:
        exception: The exception.

    Returns:
        int: The wrong return type.

    """
    print("Custom Backend Exception")
    print(exception)

    return 5


@pytest.mark.parametrize(
    "handler_fn, expected",
    [
        pytest.param(
            backend_exception_handler_with_wrong_return_type,
            pytest.raises(ValueError),
            id="wrong_return_type",
        ),
        pytest.param(
            custom_exception_handlers["partial"],
            pytest.raises(ValueError),
            id="partial",
        ),
        pytest.param(
            custom_exception_handlers["lambda"],
            pytest.raises(ValueError),
            id="lambda",
        ),
        pytest.param(
            custom_exception_handlers["wrong_argspec"],
            pytest.raises(ValueError),
            id="wrong_argspec",
        ),
        pytest.param(
            custom_exception_handlers["wrong_arg_order"],
            pytest.raises(ValueError),
            id="wrong_arg_order",
        ),
        pytest.param(
            custom_exception_handlers["valid"],
            does_not_raise(),
            id="valid_handler",
        ),
        pytest.param(
            custom_exception_handlers["method"],
            does_not_raise(),
            id="valid_class_method",
        ),
    ],
)
def test_backend_exception_handler_validation(handler_fn, expected):
    """Test that the custom backend exception handler is properly validated.

    Args:
        handler_fn: The handler function.
        expected: The expected result.

    """
    with expected:
        rx.App(backend_exception_handler=handler_fn)._validate_exception_handlers()