What is a good Python library on which to base custom http test assertions?

Question

I'm converting a code base from Ruby to Python. In Ruby/RSpec I wrote custom "matchers" which allow me to black-box test web services like this:

describe 'webapp.com' do
  it 'is configured for ssl' do
    expect('www.webapp.com').to have_a_valid_cert
  end
end

I'd like to write code to extend a Python testing framework with the same functionality. I realize that it will probably not look the same, of course. It doesn't need to be BDD. "Assert..." is just fine. Is pytest a good candidate for extending? Are there any examples of writing extensions like these?

Answer 1

Yes, pytest is good framework for doing what are you needs. We are using pytest with requests and PyHamcrest. Look at this example:

import pytest
import requests
from hamcrest import *

class SiteImpl:
    def __init__(self, url):
        self.url = url

    def has_valid_cert(self):
        return requests.get(self.url, verify=True)

@pytest.yield_fixture
def site(request):
    # setUp
    yield SiteImpl('https://' + request.param)
    # tearDown

def has_status(item):
    return has_property('status_code', item)

@pytest.mark.parametrize('site', ['google.com', 'github.com'], indirect=True)
def test_cert(site):
    assert_that(site.has_valid_cert(), has_status(200))

if __name__ == '__main__':
    pytest.main(args=[__file__, '-v'])

The code above uses parametrization for fixture site. Also yeld_fixture give you possibility to setUp and tearDown. Also you can write inline matcher has_status, which can used for easy read test assert.