morelia 0.3.0

for "Behavior Driven Development" (BDD) -- a client-facing scripting language to put the squeeze on all your features

Morelia viridis is a Python Behavior Driven Development platform, conceptually derived from Ruby’s Cucumber Framework.

It is available both at the cheeseshop and GitHub.

Mascot:

Installation

sudo pip install Morelia

Quick usage guide

Write feature description:

# calculator.feature

Feature: Addition
    In order to avoid silly mistakes
    As a math idiot
    I want to be told the sum of two numbers

Scenario: Add two numbers
    Given I have powered calculator on
    When I enter 50 into the calculator
    And I enter 70 into the calculator
    And I press add
    Then the result should be 120 on the screen

Create standard python’s unittest and hook Morelia in it:

# test_acceptance.py

import unittest
from morelia import Parser

class CalculatorTestCase(unittest.TestCase):

    def test_addition(self):
        Parser().parse_file('calculator.feature').evaluate(self)

Run test exaclty like your regular tests. Here’s raw unittest example:

python -m unittest -v test_acceptance

And you’ll see which steps are missing:

F
======================================================================
FAIL: test_addition (__main__.CalculatorTestCase)
Addition feature
----------------------------------------------------------------------
Traceback (most recent call last):
  File "test_acceptance.py", line 43, in test_addition
    Parser().parse_file('calculator.feature').evaluate(self)
  File "/.../morelia/base.py", line 184, in evaluate
    self.rip(step_matcher_visitor)
  File "/.../morelia/base.py", line 198, in rip
    visitor.after_feature(node)
  File "/.../morelia/visitors.py", line 117, in after_feature
    self._suite.fail(diagnostic)
AssertionError: Cannot match steps:

    def step_I_have_powered_calculator_on(self):
        ur'I have powered calculator on'

        # code
        pass

    def step_I_enter_50_into_the_calculator(self):
        ur'I enter 50 into the calculator'

        # code
        pass

    def step_I_enter_70_into_the_calculator(self):
        ur'I enter 70 into the calculator'

        # code
        pass

    def step_I_press_add(self):
        ur'I press add'

        # code
        pass

    def step_the_result_should_be_120_on_the_screen(self):
        ur'the result should be 120 on the screen'

        # code
        pass

Now implement steps:

# test_acceptance.py

import unittest
from morelia import Parser

class CalculatorTestCase(unittest.TestCase):

    def test_addition(self):
        Parser().parse_file('calculator.feature').evaluate(self)

    def step_I_have_powered_calculator_on(self):
        ur'I have powered calculator on'
        self.stack = []

    def step_I_enter_a_number_into_the_calculator(self, number):
        ur'I enter (\d+) into the calculator'  # match by regexp
        self.stack.append(int(number))

    def step_I_press_add(self):  #  matched by method name
        self.result = sum(self.stack)

    def step_the_result_should_be_on_the_screen(self, number):
        ur'the result should be {number} on the screen'  # match by format-like string
        assert int(number) == self.result

And run it again:

$ python -m unittest -v test_acceptance

test_addition (test_acceptance.CalculatorTestCase)
Addition feature ... ok

----------------------------------------------------------------------
Ran 1 test in 0.016s

OK

Note that Morelia does not waste anyone’s time inventing a new testing back-end just to add a layer of literacy over our testage. Steps are miniature TestCases. Your onsite customer need never know, and your unit tests and customer tests can share their support methods. The same one test button can run all TDD and BDD tests.

Look at example directory for a little more enhanced example.

Documentation

Full documentation is available at http://morelia.readthedocs.org/en/latest/index.html