Behave 基础

在你使用behave或其他BDD框架之前， 你应该选择一个断言库。 python有很多这方面的第三方库。例如： hamcrest，nose.tools,  should-dsl, sure, compare, describe等。选择一个自己喜欢的。

1. 参数化step

   # file:features/tutorial03_step_parameters.feature
   Feature: Step Parameters (tutorial03)
   
     Scenario: Blenders
       Given I put "apples" in a blender
       When  I switch the blender on
       Then  it should transform into "apple juice"
   #每个step中都包含一部分参数，这些参数可以传入不同的值
   from behave   import given, when, then
   from hamcrest import assert_that, equal_to
   from blender  import Blender
   
   @given('I put "{thing}" in a blender')
   def step_given_put_thing_into_blender(context, thing):   #参数名字可以随便定义
       context.blender = Blender()
       context.blender.add(thing)
   
   @when('I switch the blender on')
   def step_when_switch_blender_on(context):
       context.blender.switch_on()
   
   @then('it should transform into "{other_thing}"')
   def step_then_should_transform_into(context, other_thing):
       assert_that(context.blender.result, equal_to(other_thing))

2. 场景概要（scenario outline）

   Feature: Scenario Outline (tutorial04)
   
     Scenario Outline: Use Blender with <thing>
       Given I put "<thing>" in a blender
       When I switch the blender on
       Then it should transform into "<other thing>"
   
       Examples: Amphibians
           | thing         | other thing |
           | Red Tree Frog | mush        |
           | apples        | apple juice |
   
       Examples: Consumer Electronics
           | thing         | other thing |
           | iPhone        | toxic waste |
           | Galaxy Nexus  | toxic waste |
   
   #这个类型也可以叫做场景模板， template的概念， 相同的场景传入不同的参数， 参数名字是table的第一行， 可以在step中引用
   from behave   import given, when, then
   from hamcrest import assert_that, equal_to
   from blender  import Blender
   
   @given('I put "{thing}" in a blender')
   def step_given_put_thing_into_blender(context, thing):
       context.blender = Blender()
       context.blender.add(thing)
   
   @when('I switch the blender on')
   def step_when_switch_blender_on(context):
       context.blender.switch_on()
   
   @then('it should transform into "{other_thing}"')
   def step_then_should_transform_into(context, other_thing):
       assert_that(context.blender.result, equal_to(other_thing))

3. 多行text（step data）

      Scenario: Some scenario
        Given a sample text loaded into the frobulator:
           """
           Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do
           eiusmod tempor incididunt ut labore et dolore magna aliqua.
           """
   #step data在step_impl中可以直接用context.text引用
   
   from behave   import given, when, then
   from hamcrest import assert_that, equal_to
   
   @given('a sample text loaded into the frobulator')
   def step_impl(context):
       frobulator = getattr(context, "frobulator", None)
       if not frobulator:
           context.frobulator = Frobulator()
       context.frobulator.text = context.text  

4. setup table

   # file:features/tutorial06_step_setup_table.feature
   Feature: Step Setup Table (tutorial06)
   
      Scenario: Setup Table
        Given a set of specific users:
           | name      | department  |
           | Barry     | Beer Cans   |
           | Pudey     | Silly Walks |
           | Two-Lumps | Silly Walks |
   
   #步骤中的table,在step_impl中使用context.table引用, 是由dict组成的数组
   
   @given('a set of specific users')
   def step_impl(context):
       model = getattr(context, "model", None)
       if not model:
           context.model = CompanyModel()
       for row in context.table:
           context.model.add_user(row["name"], deparment=row["department"])

5. Result table 和stepup的用法相似

6. 在step中使用其他step

   # context.execute_steps函数, 不赘述
   @when('I do the same thing as before')
   def step_impl(context):
       context.execute_steps(u"""
           when I press the big {button_color} button
            and I duck
       """.format(button_color="red"))

7. background

   # file:features/tutorial09_background.feature
   Feature: Using Background -- Fight or Flight (Natural Language Part2, tutorial09)
   
       Background: Ninja fight setup
           Given the ninja encounters another opponent
   
       Scenario: Weaker opponent
           Given the ninja has a third level black-belt
   
   #Background下面的step会在该feature中所有scenario执行之前执行

8. 自定义数据类型

   在参数化的step中, 参数默认是按string解析的. 如果用户想按照其他类型处理,可自定义参数类型

     Scenario Outline: Calculator
       Given I have a calculator
       When I add "<x>" and "<y>"
       Then the calculator returns "<sum>"
   
       Examples:
           |  x  |  y | sum |
           |  1  |  1 |  2  |
   
   #写一个转换函数,并注册
   from behave import register_type
   
   def parse_number(text):
       """
       Convert parsed text into a number.
       :param text: Parsed text, called by :py:meth:`parse.Parser.parse()`.
       :return: Number instance (integer), created from parsed text.
       """
       return int(text)
   # -- REGISTER: User-defined type converter (parse_type).
   register_type(Number=parse_number)
   
   #step_impl
   @when('I add "{x:Number}" and "{y:Number}"')
   def step_impl(context, x, y):
       assert isinstance(x, int)
       assert isinstance(y, int)
       context.calculator.add2(x, y)

9. tag

   设置tag来规划自己的测试集合

   select/enable    --tags=@one    Only items with this tag.
   not (tilde/minus)    --tags=-@one    Only items without this tag.
   logical-or    --tags=@one,@two    If @one or @two is present.
   logical-and    --tags=@one --tags=@two    If both @one and @two are present.