reflex/tests/units/test_event.py

from typing import List

import pytest

from reflex.event import (
    Event,
    EventChain,
    EventHandler,
    EventSpec,
    call_event_handler,
    event,
    fix_events,
)
from reflex.state import BaseState
from reflex.utils import format
from reflex.vars.base import Field, LiteralVar, Var, field


def make_var(value) -> Var:
    """Make a variable.

    Args:
        value: The value of the var.

    Returns:
        The var.
    """
    return Var(_js_expr=value)


def test_create_event():
    """Test creating an event."""
    event = Event(token="token", name="state.do_thing", payload={"arg": "value"})
    assert event.token == "token"
    assert event.name == "state.do_thing"
    assert event.payload == {"arg": "value"}


def test_call_event_handler():
    """Test that calling an event handler creates an event spec."""

    def test_fn():
        pass

    test_fn.__qualname__ = "test_fn"

    def test_fn_with_args(_, arg1, arg2):
        pass

    test_fn_with_args.__qualname__ = "test_fn_with_args"

    handler = EventHandler(fn=test_fn)
    event_spec = handler()

    assert event_spec.handler == handler
    assert event_spec.args == ()
    assert format.format_event(event_spec) == 'Event("test_fn", {})'

    handler = EventHandler(fn=test_fn_with_args)
    event_spec = handler(make_var("first"), make_var("second"))

    # Test passing vars as args.
    assert event_spec.handler == handler
    assert event_spec.args[0][0].equals(Var(_js_expr="arg1"))
    assert event_spec.args[0][1].equals(Var(_js_expr="first"))
    assert event_spec.args[1][0].equals(Var(_js_expr="arg2"))
    assert event_spec.args[1][1].equals(Var(_js_expr="second"))
    assert (
        format.format_event(event_spec)
        == 'Event("test_fn_with_args", {arg1:first,arg2:second})'
    )

    # Passing args as strings should format differently.
    event_spec = handler("first", "second")  # type: ignore
    assert (
        format.format_event(event_spec)
        == 'Event("test_fn_with_args", {arg1:"first",arg2:"second"})'
    )

    first, second = 123, "456"
    handler = EventHandler(fn=test_fn_with_args)
    event_spec = handler(first, second)  # type: ignore
    assert (
        format.format_event(event_spec)
        == 'Event("test_fn_with_args", {arg1:123,arg2:"456"})'
    )

    assert event_spec.handler == handler
    assert event_spec.args[0][0].equals(Var(_js_expr="arg1"))
    assert event_spec.args[0][1].equals(LiteralVar.create(first))
    assert event_spec.args[1][0].equals(Var(_js_expr="arg2"))
    assert event_spec.args[1][1].equals(LiteralVar.create(second))

    handler = EventHandler(fn=test_fn_with_args)
    with pytest.raises(TypeError):
        handler(test_fn)  # type: ignore


def test_call_event_handler_partial():
    """Calling an EventHandler with incomplete args returns an EventSpec that can be extended."""

    def test_fn_with_args(_, arg1, arg2):
        pass

    test_fn_with_args.__qualname__ = "test_fn_with_args"

    def spec(a2: Var[str]) -> List[Var[str]]:
        return [a2]

    handler = EventHandler(fn=test_fn_with_args)
    event_spec = handler(make_var("first"))
    event_spec2 = call_event_handler(event_spec, spec)

    assert event_spec.handler == handler
    assert len(event_spec.args) == 1
    assert event_spec.args[0][0].equals(Var(_js_expr="arg1"))
    assert event_spec.args[0][1].equals(Var(_js_expr="first"))
    assert format.format_event(event_spec) == 'Event("test_fn_with_args", {arg1:first})'

    assert event_spec2 is not event_spec
    assert event_spec2.handler == handler
    assert len(event_spec2.args) == 2
    assert event_spec2.args[0][0].equals(Var(_js_expr="arg1"))
    assert event_spec2.args[0][1].equals(Var(_js_expr="first"))
    assert event_spec2.args[1][0].equals(Var(_js_expr="arg2"))
    assert event_spec2.args[1][1].equals(Var(_js_expr="_a2", _var_type=str))
    assert (
        format.format_event(event_spec2)
        == 'Event("test_fn_with_args", {arg1:first,arg2:_a2})'
    )


@pytest.mark.parametrize(
    ("arg1", "arg2"),
    (
        (1, 2),
        (1, "2"),
        ({"a": 1}, {"b": 2}),
    ),
)
def test_fix_events(arg1, arg2):
    """Test that chaining an event handler with args formats the payload correctly.

    Args:
        arg1: The first arg passed to the handler.
        arg2: The second arg passed to the handler.
    """

    def test_fn_with_args(_, arg1, arg2):
        pass

    test_fn_with_args.__qualname__ = "test_fn_with_args"

    handler = EventHandler(fn=test_fn_with_args)
    event_spec = handler(arg1, arg2)
    event = fix_events([event_spec], token="foo")[0]
    assert event.name == test_fn_with_args.__qualname__
    assert event.token == "foo"
    assert event.payload == {"arg1": arg1, "arg2": arg2}


@pytest.mark.parametrize(
    "input,output",
    [
        (
            ("/path", None, None),
            'Event("_redirect", {path:"/path",external:false,replace:false})',
        ),
        (
            ("/path", True, None),
            'Event("_redirect", {path:"/path",external:true,replace:false})',
        ),
        (
            ("/path", False, None),
            'Event("_redirect", {path:"/path",external:false,replace:false})',
        ),
        (
            (Var(_js_expr="path"), None, None),
            'Event("_redirect", {path:path,external:false,replace:false})',
        ),
        (
            ("/path", None, True),
            'Event("_redirect", {path:"/path",external:false,replace:true})',
        ),
        (
            ("/path", True, True),
            'Event("_redirect", {path:"/path",external:true,replace:true})',
        ),
    ],
)
def test_event_redirect(input, output):
    """Test the event redirect function.

    Args:
        input: The input for running the test.
        output: The expected output to validate the test.
    """
    path, external, replace = input
    kwargs = {}
    if external is not None:
        kwargs["external"] = external
    if replace is not None:
        kwargs["replace"] = replace
    spec = event.redirect(path, **kwargs)
    assert isinstance(spec, EventSpec)
    assert spec.handler.fn.__qualname__ == "_redirect"

    # this asserts need comment about what it's testing (they fail with Var as input)
    # assert spec.args[0][0].equals(Var(_js_expr="path"))
    # assert spec.args[0][1].equals(Var(_js_expr="/path"))

    assert format.format_event(spec) == output


def test_event_console_log():
    """Test the event console log function."""
    spec = event.console_log("message")
    assert isinstance(spec, EventSpec)
    assert spec.handler.fn.__qualname__ == "_console"
    assert spec.args[0][0].equals(Var(_js_expr="message"))
    assert spec.args[0][1].equals(LiteralVar.create("message"))
    assert format.format_event(spec) == 'Event("_console", {message:"message"})'
    spec = event.console_log(Var(_js_expr="message"))
    assert format.format_event(spec) == 'Event("_console", {message:message})'


def test_event_window_alert():
    """Test the event window alert function."""
    spec = event.window_alert("message")
    assert isinstance(spec, EventSpec)
    assert spec.handler.fn.__qualname__ == "_alert"
    assert spec.args[0][0].equals(Var(_js_expr="message"))
    assert spec.args[0][1].equals(LiteralVar.create("message"))
    assert format.format_event(spec) == 'Event("_alert", {message:"message"})'
    spec = event.window_alert(Var(_js_expr="message"))
    assert format.format_event(spec) == 'Event("_alert", {message:message})'


def test_set_focus():
    """Test the event set focus function."""
    spec = event.set_focus("input1")
    assert isinstance(spec, EventSpec)
    assert spec.handler.fn.__qualname__ == "_set_focus"
    assert spec.args[0][0].equals(Var(_js_expr="ref"))
    assert spec.args[0][1].equals(LiteralVar.create("ref_input1"))
    assert format.format_event(spec) == 'Event("_set_focus", {ref:"ref_input1"})'
    spec = event.set_focus("input1")
    assert format.format_event(spec) == 'Event("_set_focus", {ref:"ref_input1"})'


def test_set_value():
    """Test the event window alert function."""
    spec = event.set_value("input1", "")
    assert isinstance(spec, EventSpec)
    assert spec.handler.fn.__qualname__ == "_set_value"
    assert spec.args[0][0].equals(Var(_js_expr="ref"))
    assert spec.args[0][1].equals(LiteralVar.create("ref_input1"))
    assert spec.args[1][0].equals(Var(_js_expr="value"))
    assert spec.args[1][1].equals(LiteralVar.create(""))
    assert (
        format.format_event(spec) == 'Event("_set_value", {ref:"ref_input1",value:""})'
    )
    spec = event.set_value("input1", Var(_js_expr="message"))
    assert (
        format.format_event(spec)
        == 'Event("_set_value", {ref:"ref_input1",value:message})'
    )


def test_remove_cookie():
    """Test the event remove_cookie."""
    spec = event.remove_cookie("testkey")
    assert isinstance(spec, EventSpec)
    assert spec.handler.fn.__qualname__ == "_remove_cookie"
    assert spec.args[0][0].equals(Var(_js_expr="key"))
    assert spec.args[0][1].equals(LiteralVar.create("testkey"))
    assert spec.args[1][0].equals(Var(_js_expr="options"))
    assert spec.args[1][1].equals(LiteralVar.create({"path": "/"}))
    assert (
        format.format_event(spec)
        == 'Event("_remove_cookie", {key:"testkey",options:({ ["path"] : "/" })})'
    )


def test_remove_cookie_with_options():
    """Test the event remove_cookie with options."""
    options = {
        "path": "/foo",
        "domain": "example.com",
        "secure": True,
        "sameSite": "strict",
    }
    spec = event.remove_cookie("testkey", options)
    assert isinstance(spec, EventSpec)
    assert spec.handler.fn.__qualname__ == "_remove_cookie"
    assert spec.args[0][0].equals(Var(_js_expr="key"))
    assert spec.args[0][1].equals(LiteralVar.create("testkey"))
    assert spec.args[1][0].equals(Var(_js_expr="options"))
    assert spec.args[1][1].equals(LiteralVar.create(options))
    assert (
        format.format_event(spec)
        == f'Event("_remove_cookie", {{key:"testkey",options:{str(LiteralVar.create(options))}}})'
    )


def test_clear_local_storage():
    """Test the event clear_local_storage."""
    spec = event.clear_local_storage()
    assert isinstance(spec, EventSpec)
    assert spec.handler.fn.__qualname__ == "_clear_local_storage"
    assert not spec.args
    assert format.format_event(spec) == 'Event("_clear_local_storage", {})'


def test_remove_local_storage():
    """Test the event remove_local_storage."""
    spec = event.remove_local_storage("testkey")
    assert isinstance(spec, EventSpec)
    assert spec.handler.fn.__qualname__ == "_remove_local_storage"
    assert spec.args[0][0].equals(Var(_js_expr="key"))
    assert spec.args[0][1].equals(LiteralVar.create("testkey"))
    assert (
        format.format_event(spec) == 'Event("_remove_local_storage", {key:"testkey"})'
    )


def test_event_actions():
    """Test DOM event actions, like stopPropagation and preventDefault."""
    # EventHandler
    handler = EventHandler(fn=lambda: None)
    assert not handler.event_actions
    sp_handler = handler.stop_propagation
    assert handler is not sp_handler
    assert sp_handler.event_actions == {"stopPropagation": True}
    pd_handler = handler.prevent_default
    assert handler is not pd_handler
    assert pd_handler.event_actions == {"preventDefault": True}
    both_handler = sp_handler.prevent_default
    assert both_handler is not sp_handler
    assert both_handler.event_actions == {
        "stopPropagation": True,
        "preventDefault": True,
    }

    throttle_handler = handler.throttle(300)
    assert handler is not throttle_handler
    assert throttle_handler.event_actions == {"throttle": 300}

    debounce_handler = handler.debounce(300)
    assert handler is not debounce_handler
    assert debounce_handler.event_actions == {"debounce": 300}

    all_handler = handler.stop_propagation.prevent_default.throttle(200).debounce(100)
    assert handler is not all_handler
    assert all_handler.event_actions == {
        "stopPropagation": True,
        "preventDefault": True,
        "throttle": 200,
        "debounce": 100,
    }

    assert not handler.event_actions

    # Convert to EventSpec should carry event actions
    sp_handler2 = handler.stop_propagation.throttle(200)
    spec = sp_handler2()
    assert spec.event_actions == {"stopPropagation": True, "throttle": 200}
    assert spec.event_actions == sp_handler2.event_actions
    assert spec.event_actions is not sp_handler2.event_actions
    # But it should be a copy!
    assert spec.event_actions is not sp_handler2.event_actions
    spec2 = spec.prevent_default
    assert spec is not spec2
    assert spec2.event_actions == {
        "stopPropagation": True,
        "preventDefault": True,
        "throttle": 200,
    }
    assert spec2.event_actions != spec.event_actions

    # The original handler should still not be touched.
    assert not handler.event_actions


def test_event_actions_on_state():
    class EventActionState(BaseState):
        def handler(self):
            pass

    handler = EventActionState.handler
    assert isinstance(handler, EventHandler)
    assert not handler.event_actions

    sp_handler = EventActionState.handler.stop_propagation
    assert sp_handler.event_actions == {"stopPropagation": True}
    # should NOT affect other references to the handler
    assert not handler.event_actions


def test_event_var_data():
    class S(BaseState):
        x: Field[int] = field(0)

        @event
        def s(self, value: int):
            pass

    # Handler doesn't have any _var_data because it's just a str
    handler_var = Var.create(S.s)
    assert handler_var._get_all_var_data() is None

    # Ensure spec carries _var_data
    spec_var = Var.create(S.s(S.x))
    assert spec_var._get_all_var_data() == S.x._get_all_var_data()

    # Needed to instantiate the EventChain
    def _args_spec(value: Var[int]) -> tuple[Var[int]]:
        return (value,)

    # Ensure chain carries _var_data
    chain_var = Var.create(EventChain(events=[S.s(S.x)], args_spec=_args_spec))
    assert chain_var._get_all_var_data() == S.x._get_all_var_data()