Behaviour driven development.

fight_or_flight.feature

Feature: Fight of flight

  In order to increase the ninja survival rate
  As a ninja commander
  I want my ninjas to decide whether to take on an
  oponent based on their skill levels

  Scenario: Weaker opponent
    Given the ninja has a third level black-belt
    When attacked by a samurai
    Then the ninja should engage the opponent

  Scenario: Stronger opponent
    Given the ninja has a third level black-belt
    When attacked by Chuck Norris
    Then the ninja  should run for his life

  Scenario: Unknown opponent
    Given the ninja has a third level black-belt
    When attacked by an an enemy he can't gauge
    Then the ninja should remain idle

ninja.py

from grappa import should
from behave import given, when, then


class Ninja(object):
    def __init__(self):
        self.status = 'idle'

    def face_oponent(self, opponent):
        if opponent == 'samurai':
            self.status = 'engaging'
        if opponent == 'Chuck Norris':
            self.status = 'running for dear life'


@given(u'the ninja has a third level black-belt')
def ninja_with_level(context):
    context.ninja = Ninja()


@when(u'attacked by a samurai')
def attacked_by_sammuray(context):
    context.ninja.face_oponent('samurai')


@then(u'the ninja should engage the opponent')
def decides_to_engage(context):
    context.ninja.status | should.be.equal.to('engaging')


@when(u'attacked by Chuck Norris')
def attacked_by_chuck(context):
    context.ninja.face_oponent('Chuck Norris')


@then(u'the ninja  should run for his life')
def decides_to_run(context):
    context.ninja.status | should.be.equal.to('running for dear life')


@when(u'attacked by an an enemy he can\'t gauge')
def attacked_by_misterious_opponent(context):
    context.ninja.face_oponent('Mistery oponent')    


@then(u'the ninja should remain idle')
def decides_to_remain_idle(context):
    context.ninja.status | should.be.equal.to('idle')

Feature: Fight of flight # features/fight_or_flight.feature:1
  In order to increase the ninja survival rate
  As a ninja commander
  I want my ninjas to decide whether to take on an
  oponent based on their skill levels
  Scenario: Weaker opponent                      # features/fight_or_flight.feature:8
    Given the ninja has a third level black-belt # features/steps/ninja.py:16 0.000s
    When attacked by a samurai                   # features/steps/ninja.py:21 0.000s
    Then the ninja should engage the opponent    # features/steps/ninja.py:26 0.000s

  Scenario: Stronger opponent                    # features/fight_or_flight.feature:13
    Given the ninja has a third level black-belt # features/steps/ninja.py:16 0.000s
    When attacked by Chuck Norris                # features/steps/ninja.py:31 0.000s
    Then the ninja  should run for his life      # features/steps/ninja.py:36 0.000s

  Scenario: Unknown opponent                     # features/fight_or_flight.feature:18
    Given the ninja has a third level black-belt # features/steps/ninja.py:16 0.000s
    When attacked by an an enemy he can't gauge  # features/steps/ninja.py:41 0.000s
    Then the ninja should remain idle            # features/steps/ninja.py:46 0.000s