结合httpretty和pytest tmpdir

Question

The following pytest-test uses httpretty, to mock a request. It writes the fetched data to a file:

import requests
import httpretty
import json
from os import listdir
from os.path import join

@httpretty.activate
def test_write_file_from_datasource():
    tmpdir = './mytestdir'

    # mock the connection
    concert_url = 'http://apis.is/concerts'
    httpretty.register_uri(httpretty.GET, concert_url,
                           body = json.dumps({'results': []}),
                           content_type='application/json')
    # fetch data
    concerts = requests.get(concert_url).json()

    # write data
    with open(join(tmpdir, 'concerts.json'), 'w') as json_data:
        json.dump(concerts, json_data, indent=2)

    assert len(listdir(tmpdir)) == 1

What I would like to do now, is making use of the pytest tmpdir feature. To reach this, I wrote a test like this (imports same as above):

@httpretty.activate
def test_write_file_from_datasource_failing(tmpdir):
    tmpdir = str(tmpdir)
    # mock the connection
    concert_url = 'http://apis.is/concerts'
    httpretty.register_uri(httpretty.GET, concert_url,
                           body = json.dumps({'results': []}),
                           content_type='application/json')
    # fetch data
    concerts = requests.get(concert_url).json()

    # write data
    with open(join(tmpdir, 'concerts.json'), 'w') as json_data:
        json.dump(concerts, json_data, indent=2)

    assert len(listdir(tmpdir)) == 1

It fails, because the httpretty decorator seems to have problems with the additional parameter:

TypeError: test_write_file_from_datasource_failing() takes exactly 1 argument (0 given)

Any ideas, how to fix this?

Answer 1

It seems that this decorator does not work well with pytest's funcargs.

The only solution I see is to manually call httprertty.enable() and httpretty.disable() methods.

Or create a fixture:

@pytest.yield_fixture
def http_pretty_mock():
    httpretty.enable()
    yield
    httpretty.disable()


def test_write_file_from_datasource_failing(http_pretty_mock, tmpdir):
    tmpdir = str(tmpdir)
    # mock the connection