Introduction
Library to convert BDD features into Python unittest.TestCase classes. Run the tests with your favorite test runner, like pytest, unittest or nose. See the demo folder for an example.
Example
Let's take a calculator as an example. Create a plain text file called calculator.feature containing the BDD-style feature description:
Feature: Basic math operations Test addition Scenario: add Given the value 10 When adding 7 Then the result is 17 Scenario: add a negative value Given the value 19 When adding -11 Then the result is 8
This is the text you can discuss with the customer and agree on. Next write a backing file called test_calculator.py containing the code to run this feature:
import os from bdd import Environment from calculator import Calculator env = Environment() env.context.calculator = Calculator() @env.given('the value {:d}') def step(context, value): context.calculator.value = value @env.when('adding {:d}') def step(context, value): context.calculator.add(value) @env.then('the result is {:d}') def step(context, value): assert context.calculator.value == value def rel(p): this_dir = os.path.dirname(os.path.abspath(__file__)) return os.path.join(this_dir, p) CalculatorTestCase = env.load_feature_as_testcase('calculator.feature')
Finally, write the actual production code to implement the calculator, in a file called calculator.py:
class Calculator: def __init__(self): self.value = 0 def add(self, value): self.value += value
Now run the tests with, for example, pytest:
$ python -m pytest test_calculator.py -v =========== test session starts =========================== platform linux -- Python 3.5.1, pytest-2.9.1 collected 2 items test_calculator.py::CalculatorTestCase::test_scenario_0 <- bdd.py PASSED test_calculator.py::CalculatorTestCase::test_scenario_1 <- bdd.py PASSED
References
A really good python bdd library is behave.
Changelog
0.3
- Add tag support
0.2 (Jun 4, 2016)
- Added more demos
0.1 (Jun 2, 2016)
- Initial release