pytest-bdd：如何从@given获取当前方案？

Question

I need to get scenario name or other unique information about currently running test in @given method.

In my test I declare, that I have some resource. This resource is being extracted/created from web api like that:

@given('I have a new article')
def new_article(vcr_fixture):
    with vcr_fixture.use_cassette('new_article'):  # I need to use different cassette name for different scenarios 
        return create_new_article()

The problem here is that I can have multiple scenarios with different parameters and I would like to use same resource multiple times. In this case I need different cassettes for each case. And I can't use those parameters for differentiating between cassettes, as they could be applied after the resource being created (for example, adding comments). I tried to add request to the @given fixture, but could not find any unique information in it.

Answer 1

To inspect your scenario name, you can use parsers.

from pytest_bdd import parsers
...

@given(parsers.parse('I have a {article_name}')
def new_article(vcr_fixture, article_name):
    with vcr_fixture.use_cassette(article_name):        
        return create_new_article()

Not sure if this if this answers your question, though..

Answer 2

nAlthough what user2292262 suggested works, it doesn't work as one would have expected when start learning pytest-bdd (at least least what I'd have expected).

The solution AIUI is creating a fixture for each article you have among your tests, without automatisms (ie function that create for you the data you need dynamically).

This in a testing context should be reasonably doable, since the data set you have is not the real one, but a subset and the data you have as pre-reqs (the Given verbs) should be even less. You can think of populate the fixtures with a script if this gets out of hand, by querying the DB and writing a templated file accordingly.

@given(parsers.parse('I have an article called foo')
def article_foo(vcr_fixture):
    with vcr_fixture.use_cassette('foo'):
         return create_new_article()

@given(parsers.parse('I have an article called bar')
def article_bar(vcr_fixture):
    with vcr_fixture.use_cassette('bar'):
         return create_new_article()


etc.

The problem in the 'factory' code of the other solution

@given(parsers.parse('I have a {article_name}')
def new_article(vcr_fixture, article_name):
    with vcr_fixture.use_cassette(article_name):        
         return create_new_article()

is that you are still tempted to use it as

Given I have an article called Foo
And I have an article called Bar
When I edit Foo
Then Bar is untouched

but this scenario won't work, because under the curtains you are actually using the same fixture twice but with different 'content'

In other words, with that code someone would 'new_article' for two 'data' instances. This goes against what pytest likes.

Also, from a purist point of view, the Given verbs in BDD should be facts, not things that create facts.