Parameterized Scenarios

To create a parameterized scenario in Vedro, you'll need to use the @vedro.params decorator. This decorator allows you to pass different parameters to the scenario, which will then be executed multiple times with the provided parameters.

Here's an example of a parameterized scenario:

import httpx
import vedro
from vedro import params


class Scenario(vedro.Scenario):
    subject = "get status"

    @params(200)
    @params(404)
    def __init__(self, status):
        self.status = status

    def given_url(self):
        self.url = f"https://httpbin.org/status/{self.status}"

    def when_user_sends_request(self):
        self.response = httpx.get(self.url)

    def then_it_should_return_expected_status(self):
        assert self.response.status_code == self.status

In this example, the scenario is executed with two distinct parameters: status=200 and status=404.

Subject Interpolation

You can also incorporate interpolation into the scenario's subject. The subject is a descriptive string for the scenario and can include placeholders for parameter values. To interpolate these values, use the format string syntax.

import vedro
from vedro import params


class Scenario(vedro.Scenario):
    subject = "get status {status}"

    @params(200)
    @params(404)
    def __init__(self, status):
        self.status_code = status

    ...

In this example, the subject of the scenario will change based on the value of the status parameter.

$ vedro run 

Scenarios
* 
 ✔ get status 200
 ✔ get status 404
 
# 2 scenarios, 2 passed, 0 failed, 0 skipped (1.93s)

Subject Parameterization

You can also parameterize the subject itself. To achieve this, include the subject as a parameter in the @params decorator and define it in the scenario's constructor.

Here's an example of a scenario with a parameterized subject:

import vedro
from vedro import params


class Scenario(vedro.Scenario):
    subject = "{subject}"

    @params("get ok status", 200)
    @params("get not found status", 404)
    def __init__(self, subject, status):
        self.subject = subject
        self.status = status

    ...

Output:

$ vedro run

Scenarios
* 
 ✔ get ok status
 ✔ get not found status
 
# 2 scenarios, 2 passed, 0 failed, 0 skipped (1.22s)