File Promotion Example

codepalousa-testing-boundaries.md

The gist for: Code PaLOUsa Testing Application Boundaries.

test_email.py

from flask_mail import Message
from keg import current_app

from pypicalc.app import PyPICalc


class IMailService(object):
    def send(self):
        raise NotImplemented


class MockMailService(IMailService):
    sent_messages = []

    def send(self, msg):
        if current_app.testing:
            self.sent_messages.append(msg)
        else:
            PyPICalc.mail.send(msg)


class MailService(IMailService):
    def send(self, msg):
        PyPICalc.mail.send(msg)


class ServiceManager(object):
    def __init__(self):
        if current_app.testing:
            self.mail = MockMailService()
        else:
            self.mail = MailService()

services = ServiceManager()


def send_contact_email(user_email, subject, body):
    msg = Message(subject, reply_to=user_email)
    msg.add_recipient('somebodyelse@example.com')
    msg.body = body
    services.mail.send(msg)


class TestSendContactEmail(object):

    def test_message_creation(self):
        send_contact_email('me@me.com', 'hi there', 'you rock!')
        assert len(services.mail.sent_messages) == 1
        msg = services.mail.sent_messages[0]

        assert msg.subject == 'hi there'
        assert msg.reply_to == 'me@me.com'
        assert msg.sender == 'fakesender@example.com'
        assert msg.recipients == ['somebodyelse@example.com']

test_file_promotion.py

import csv

import arrow


def calculate_age_sum(csv_fpath):

    with open(csv_fpath) as csvfo:
        reader = csv.reader(csvfo)
        return calculate_age_sum_helper(reader)


def calculate_age_sum_helper(iterable):
    age_sum = 0
    for row in iterable:
        date_delta = arrow.now() - arrow.get(row[1])
        age_sum += date_delta.days // 365
    return age_sum


class TestAgeSum(object):

    def test_temporary_file(self, tmpdir):
        fake_csv_tmpfile = tmpdir.join('fake.csv')
        with fake_csv_tmpfile.open('w') as csv:
            csv.write('amy,2000-01-01\n')
            csv.write('judy,1980-02-01\n')

        csv_fpath = fake_csv_tmpfile.strpath
        assert calculate_age_sum(csv_fpath) == 52

    def test_iterable_data(self):
        data = [
            ('amy', '2000-01-01'),
            ('judy', '1980-02-01'),
        ]
        assert calculate_age_sum_helper(data) == 52

test_web_request.py

import requests
import requests_mock


def calc_project_bandwidth(project_data):
    total_bytes = 0
    if 'urls' not in project_data:
        return 0
    for url in project_data['urls']:
        total_bytes += url['size'] * url['downloads']
    return total_bytes


def get_project_bandwidth(project_name, _requests=requests, _cpb=calc_project_bandwidth):
    url = 'https://pypi.python.org/pypi/{0}/json'.format(project_name)
    resp = _requests.get(url)
    return _cpb(resp.json())


class TestGetProjectBandwidth(object):

    def test_all_with_requests_mock(self):
        with requests_mock.mock() as m:
            m.get('https://pypi.python.org/pypi/foo/json',
                  json={'urls': [{'downloads': 5, 'size': 10}]})

            assert get_project_bandwidth('foo') == 50