test_event.py

# Copyright (c) 2016 Uber Technologies, Inc.
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
# THE SOFTWARE.

from __future__ import absolute_import

import mock
import pytest
from mock import MagicMock
from tornado.gen import maybe_future

from tchannel import TChannel
from tchannel import schemes
from tchannel.errors import BadRequestError
from tchannel.event import EventEmitter
from tchannel.event import EventHook
from tchannel.event import EventRegistrar
from tchannel.event import EventType


@pytest.mark.parametrize('event_name', EventType._fields)
@pytest.mark.gen_test
def test_event_hook(event_name):
    event_value = getattr(EventType, event_name)
    mock_hook = MagicMock(spec=EventHook)

    event_emitter = EventEmitter()
    event_emitter.register_hook(mock_hook)

    yield event_emitter.fire(event_value, None)
    assert getattr(mock_hook, event_name).called is True


@pytest.mark.gen_test
def test_decorator_registration():
    event_emitter = EventEmitter()
    registrar = EventRegistrar(event_emitter)

    called = [False, False]

    # Multiple handlers can be defined for the same event.
    @registrar.before_send_request
    def foo():
        called[0] = True

    @registrar.before_send_request
    def bar():
        called[1] = True

    yield event_emitter.fire(EventType.before_send_request)

    assert called[0] is True
    assert called[1] is True


@pytest.mark.gen_test
def test_after_send_error_event_called():
    tchannel = TChannel('test')
    tchannel.listen()
    with mock.patch(
        'tchannel.event.EventEmitter.fire', autospec=True,
    ) as mock_fire:
        mock_fire.return_value = maybe_future(None)
        with pytest.raises(BadRequestError):
            yield tchannel.call(
                scheme=schemes.RAW,
                service='test',
                arg1='endpoint',
                hostport=tchannel.hostport,
                timeout=0.3,
            )
        mock_fire.assert_any_call(
            mock.ANY, EventType.after_send_error, mock.ANY,
        )