How do I handle dependencies between scenarios in Lettuce?

Question

I like using Lettuce to define test cases. In many cases, it's easy to write Lettuce scenarios in such a way that they can be run either atomically or as part of other scenarios in a feature. However, I find that Lettuce is also a useful tool to try and reason about and implement more complex integration tests. In these cases, it makes sense to break up the tests into scenarios, but define a dependency on a previous scenario. That way I can run a scenario without having to explicitly define which other scenarios need to be run. It also makes the dependency clear in the scenario definition. This might look something like this:

Scenario: Really long scenario
    Given some condition
    Given another condition
    Then something
    ...

Scenario: A dependent scenario
    Given the scenario "Really long scenario" has been run
    Given new condition
    Then some stuff
    ...

Then I could do something like:

@step('Given the scenario "([^"]*)" has been run')
def check_scenario(step, sentence):
    scenario = get_scenario(sentence) # This what I don't know how to do
    if not scenario.ran:
        scenario.run()

How do you handle this situation? Are there any gotchas I'm missing with this approach? Taking a quick look through the API docs and the source code, it didn't seem like there was an easy way to retrieve a scenario by it's string.

score 1 · Answer 1 · answered Jul 16 '13 at 16:02

1

The only thing I know about is defining new steps which call previously defined steps: Check out the tutorial about that topic. Maybe this can be a good workaround for your problem.

answered Jul 16 '13 at 16:02

Torsten Engelbrecht

13,318
4
46
48

score 0 · Answer 2 · answered Jul 21 '13 at 22:02

0

You can use world in order to store data between your scenarios.

@before.each_feature
def feature_setup(feature):
    ...
    world.feature_data = dict()
    ...

You can access this data from everywhere you have access to world

You can mix it with your terrain.py file in order to save data between steps, scenarios, features.

answered Jul 21 '13 at 22:02

PukeCloud

116
8

Thanks for this mention. I'm aware of this capability. I was asking how to implement dependencies between scenarios both in the definition and the implementation. I think @Torsten's suggestion below gets closer to this. – Geoffrey Hing Jul 22 '13 at 16:29

How do I handle dependencies between scenarios in Lettuce?

2 Answers2