flask/tests/test_signals.py

# -*- coding: utf-8 -*-
"""
    tests.signals
    ~~~~~~~~~~~~~~~~~~~~~~~

    Signalling.

    :copyright: (c) 2014 by Armin Ronacher.
    :license: BSD, see LICENSE for more details.
"""

import pytest

try:
    import blinker
except ImportError:
    blinker = None

import flask
from tests import TestFlask


pytestmark = pytest.mark.skipif(
    blinker is None,
    reason='Signals require the blinker library.'
)

class TestSignals(TestFlask):

    def test_template_rendered(self):
        app = flask.Flask(__name__)

        @app.route('/')
        def index():
            return flask.render_template('simple_template.html', whiskey=42)

        recorded = []

        def record(sender, template, context):
            recorded.append((template, context))

        flask.template_rendered.connect(record, app)
        try:
            app.test_client().get('/')
            assert len(recorded) == 1
            template, context = recorded[0]
            assert template.name == 'simple_template.html'
            assert context['whiskey'] == 42
        finally:
            flask.template_rendered.disconnect(record, app)

    def test_request_signals(self):
        app = flask.Flask(__name__)
        calls = []

        def before_request_signal(sender):
            calls.append('before-signal')

        def after_request_signal(sender, response):
            assert response.data == b'stuff'
            calls.append('after-signal')

        @app.before_request
        def before_request_handler():
            calls.append('before-handler')

        @app.after_request
        def after_request_handler(response):
            calls.append('after-handler')
            response.data = 'stuff'
            return response

        @app.route('/')
        def index():
            calls.append('handler')
            return 'ignored anyway'

        flask.request_started.connect(before_request_signal, app)
        flask.request_finished.connect(after_request_signal, app)

        try:
            rv = app.test_client().get('/')
            assert rv.data == b'stuff'

            assert calls == ['before-signal', 'before-handler', 'handler',
                             'after-handler', 'after-signal']
        finally:
            flask.request_started.disconnect(before_request_signal, app)
            flask.request_finished.disconnect(after_request_signal, app)

    def test_request_exception_signal(self):
        app = flask.Flask(__name__)
        recorded = []

        @app.route('/')
        def index():
            1 // 0

        def record(sender, exception):
            recorded.append(exception)

        flask.got_request_exception.connect(record, app)
        try:
            assert app.test_client().get('/').status_code == 500
            assert len(recorded) == 1
            assert isinstance(recorded[0], ZeroDivisionError)
        finally:
            flask.got_request_exception.disconnect(record, app)

    def test_appcontext_signals(self):
        app = flask.Flask(__name__)
        recorded = []

        def record_push(sender, **kwargs):
            recorded.append('push')

        def record_pop(sender, **kwargs):
            recorded.append('pop')

        @app.route('/')
        def index():
            return 'Hello'

        flask.appcontext_pushed.connect(record_push, app)
        flask.appcontext_popped.connect(record_pop, app)
        try:
            with app.test_client() as c:
                rv = c.get('/')
                assert rv.data == b'Hello'
                assert recorded == ['push']
            assert recorded == ['push', 'pop']
        finally:
            flask.appcontext_pushed.disconnect(record_push, app)
            flask.appcontext_popped.disconnect(record_pop, app)

    def test_flash_signal(self):
        app = flask.Flask(__name__)
        app.config['SECRET_KEY'] = 'secret'

        @app.route('/')
        def index():
            flask.flash('This is a flash message', category='notice')
            return flask.redirect('/other')

        recorded = []

        def record(sender, message, category):
            recorded.append((message, category))

        flask.message_flashed.connect(record, app)
        try:
            client = app.test_client()
            with client.session_transaction():
                client.get('/')
                assert len(recorded) == 1
                message, category = recorded[0]
                assert message == 'This is a flash message'
                assert category == 'notice'
        finally:
            flask.message_flashed.disconnect(record, app)