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第七讲：Behave 框架使用

培训目标

掌握 behave 的使用方式，可以使用 behave 写自动化 case。

课程笔记

一、logging

1. 在哪里学习？

文档：https://docs.python.org/3.7/library/logging.config.html
https://docs.python.org/3.7/library/logging.html

2. logging模块四大组件

组件

说明

loggers

提供应用程序代码直接使用的接口

handlers

用于将日志记录发送到指定的目的位置

filters

提供更细粒度的日志过滤功能，用于决定哪些日志记录将会被输出（其它的日志记录将会被忽略）

formatters

用于控制日志信息的最终输出格式

二、如何使用behave

1. 在哪里学习？

基础概念、配置、操作https://behave.readthedocs.io/en/stable/
进阶使用https://github.com/behave/behave
- 自动生成失败用例为feature文件：https://github.com/behave/behave/blob/master/features/formatter.rerun.feature
- 重试：https://github.com/behave/behave/blob/master/features/runner.scenario\_autoretry.feature

2. behave测试框架由哪些元素构成

https://behave.readthedocs.io/en/latest/tutorial.html#

feature文件
step实现
环境控制？
a. feature文件
https://behave.readthedocs.io/en/latest/api.html#runner-operation

# -- SIMPLIFIED GHERKIN GRAMMAR (for Gherkin v6):
# CARDINALITY DECORATOR: '*' means 0..N (many), '?' means 0..1 (optional)
# EXAMPLE: Feature
#   A Feature can have many Tags (as TaggableStatement: zero or more tags before its keyword).
#   A Feature can have an optional Background.
#   A Feature can have many Scenario(s), meaning zero or more Scenarios.
#   A Feature can have many ScenarioOutline(s).
#   A Feature can have many Rule(s).
Feature(TaggableStatement):
    Background?
    Scenario*
    ScenarioOutline*
    Rule*

Background:
    Step*           # Background steps are injected into any Scenario of its scope.

Scenario(TaggableStatement):
    Step*

ScenarioOutline(ScenarioTemplateWithPlaceholders):
    Scenario*       # Rendered Template by using ScenarioOutline.Examples.rows placeholder values.

Rule(TaggableStatement):
    Background?     # Behave-specific extension (after removal from final Gherkin v6).
    Scenario*
    ScenarioOutline*

b. step实现

feature文件：

Scenario: Search for an account
   Given I search for a valid account
    Then I will see the account details

step代码实现：

@given('I search for a valid account')
def step_impl(context):
    context.browser.get('http://localhost:8000/index')
    form = get_element(context.browser, tag='form')
    get_element(form, name="msisdn").send_keys('61415551234')
    form.submit()

@then('I will see the account details')
def step_impl(context):
    elements = find_elements(context.browser, id='no-account')
    eq_(elements, [], 'account not found')
    h = get_element(context.browser, id='account-head')
    ok_(h.text.startswith("Account 61415551234"),
        'Heading %r has wrong text' % h.text)

c. 环境控制

在environment.py模块中定义了在指定事件发生前后执行的代码

before\_step(context, step), after\_step(context, step)

These run before and after every step.

before\_scenario(context, scenario), after\_scenario(context, scenario)

These run before and after each scenario is run.

before\_feature(context, feature), after\_feature(context, feature)

These run before and after each feature file is exercised.

before\_tag(context, tag), after\_tag(context, tag)

These run before and after a section tagged with the given name. They are invoked for each tag encountered in the order they’re found in the feature file. Seecontrolling things with tags.

before\_all(context), after\_all(context)

These run before and after the whole shooting match.

3. 以上元素的调用顺序

https://behave.readthedocs.io/en/latest/api.html#runner-operation

https://behave.readthedocs.io/en/latest/gherkin.html#background

# -- PSEUDO-CODE:
# HOOK: before_tag(), after_tag() is called for Feature, Rule, Scenario
ctx = createContext()
call-optional-hook before_all(ctx)
for feature in all_features:
    for tag in feature.tags:
        call-optional-hook before_tag(ctx, tag)
    call-optional-hook before_feature(ctx, feature)
    for run_item in feature.run_items:  # CAN BE: Rule, Scenario, ScenarioOutline
        execute_run_item(run_item, ctx)
    call-optional-hook after_feature(ctx, feature)
    for tag in feature.tags:
        call-optional-hook after_tag(ctx, tag)
call-optional-hook after_all(ctx)
 
function execute_run_item(run_item, ctx):
    if run_item isa ScenarioOutline:
        # -- CASE: ScenarioOutline
        # HINT: All Scenarios are already created from Example(s) rows.
        scenario_outline = run_item
        for scenario in scenario_outline.scenarios:
            execute_run_item(scenario, ctx)
    else if run_item isa Scenario:
        # -- CASE: Scenario
        # HINT: Background steps are injected before scenario steps.
        scenario = run_item
        for tag in scenario.tags:
            call-optional-hook before_tag(ctx, tag)
        call-optional-hook before_scenario(ctx, scenario)
        for step in scenario.steps:
            call-optional-hook before_step(ctx, step)
            step.run(ctx)
            call-optional-hook after_step(ctx, step)
        call-optional-hook after_scenario(ctx, scenario)
        for tag in scenario.tags:
            call-optional-hook after_tag(ctx, tag)

4. context属性的生命周期

https://behave.readthedocs.io/en/latest/context\_attributes.html#user-attributes

三、断言 hamcrest

1. 在那里学习？

文档：https://pyhamcrest.readthedocs.io/en/v2.0.2/

代码：https://github.com/hamcrest/PyHamcrest

2. 预定义的matcher

*   Object
    *   `equal_to`\- match equal object
    *   `has_length`\- match`len()`
    *   `has_property`\- match value of property with given name
    *   `has_properties`\- match an object that has all of the given properties.
    *   `has_string`\- match`str()`
    *   `instance_of`\- match object type
    *   `none`,`not_none`\- match`None`, or not`None`
    *   `same_instance`\- match same object
    *   `calling, raises`\- wrap a method call and assert that it raises an exception
*   Number
    *   `close_to`\- match number close to a given value
    *   `greater_than`,`greater_than_or_equal_to`,`less_than`,`less_than_or_equal_to`\- match numeric ordering
*   Text
    *   `contains_string`\- match part of a string
    *   `ends_with`\- match the end of a string
    *   `equal_to_ignoring_case`\- match the complete string but ignore case
    *   `equal_to_ignoring_whitespace`\- match the complete string but ignore extra whitespace
    *   `matches_regexp`\- match a regular expression in a string
    *   `starts_with`\- match the beginning of a string
    *   `string_contains_in_order`\- match parts of a string, in relative order
*   Logical
    *   `all_of`\-`and`together all matchers
    *   `any_of`\-`or`together all matchers
    *   `anything`\- match anything, useful in composite matchers when you don't care about a particular value
    *   `is_not`,`not_`\- negate the matcher
*   Sequence
    *   `contains`\- exactly match the entire sequence
    *   `contains_inanyorder`\- match the entire sequence, but in any order
    *   `has_item`\- match if given item appears in the sequence
    *   `has_items`\- match if all given items appear in the sequence, in any order
    *   `is_in`\- match if item appears in the given sequence
    *   `only_contains`\- match if sequence's items appear in given list
    *   `empty`\- match if the sequence is empty
*   Dictionary
    *   `has_entries`\- match dictionary with list of key-value pairs
    *   `has_entry`\- match dictionary containing a key-value pair
    *   `has_key`\- match dictionary with a key
    *   `has_value`\- match dictionary with a value
*   Decorator
    *   `calling`\- wrap a callable in a deferred object, for subsequent matching on calling behaviour
    *   `raises`\- Ensure that a deferred callable raises as expected
    *   `described_as`\- give the matcher a custom failure description
    *   `is_`\- decorator to improve readability - see Syntactic sugar below

第七讲：Behave 框架使用

培训目标

课程笔记

一、logging

1. 在哪里学习？

2. logging模块四大组件

二、如何使用behave

1. 在哪里学习？

2. behave测试框架由哪些元素构成

a. feature文件

b. step实现

c. 环境控制

3. 以上元素的调用顺序

4. context属性的生命周期

三、断言 hamcrest

1. 在那里学习？

2. 预定义的matcher