Generator

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Generator is a helper for generating test methods for nose while still using unittest.

Installation

pip install test-generator

Introduction

Have you ever written tests that loop through a list of inputs to validate the functionality?

Something like?

from mything import thingy

class MyTestCase(unittest.TestCase):
    def test_thingy(self):
        for input in [
            'a',
            'b',
            'cccc',
            'ddd'
            'eeeeee',
            'f',
            'g'
        ]:
            self.assertTrue(thingy(input))

But running in a loop limits all the functionality in TestCase like per- test setUp or tearDown. It also fails on the first input and you can’t run a single test input, you have to run them all? (Doesn’t work well when each test is more complicated than this toy case).

Instead, what if you wrote your test like:

from generator import generator, generate
from mything import thingy

@generator
class MyTestCase(unittest.TestCase):

    @generate('a', 'b', 'cccc', 'ddd', 'eeeeee', 'f', 'g')
    def test_thingy(self, input):
        self.assertTrue(thingy(input))

And when you run your tests, you see:

----------------------------------------------------------------------
Ran 7 tests in 0.001s

OK

Generator gives you simple decorators to mulitply your test methods based on an argument list. It’s great for checking a range of inputs, a list of error conditions or expected status codes.

Examples

API Client Error Handling

Let’s make sure our API client properly handles error conditions and raises a generic APIError under the conditions. We’ll use mock to patch out the actual API call to return our response.

import mock
from generator import generator, generate
from example import client, APIError

@generator
class TestAPIErrorHandling(unittest.TestCase):

    @generate(400, 401, 403, 404, 500, 502, 503)
    def test_error(self, status_code):
        with mock.patch(client, '_request') as _request_stub:
            _request_stub.return_value.status_code = status_code

            self.assertRaises(APIError):
                client.get('/path/')

Test Fixtures

Let’s make sure our API client properly handles error conditions and raises a generic APIError under the conditions. We’ll use mock to patch out the actual API call to return our response.

from generator import generator, generate
from example.sanitize import strip_tags

@generator
class TestStripTags(unittest.TestCase):

    @generate(
        ('<h1>hi</h1>', 'hi'),
        ('<script></script>something', 'something'),
        ('<div class="important"><p>some text</p></div>', 'some text'),
    )
    def test_strip_tags(self, input, expected):
        self.assertEqual(strip_tags(input), expected)