Scenario outlines

背景

以前写接口自动化，一般都会用到数据驱动，假设 bdd 在没有数据驱动的情况下会怎么写？

Feature: Eating
    Scenario: Eat 5 out of 12
        Given there are 12 cucumbers
        When I eat 5 cucumbers
        Then I should have 7 cucumbers
    Scenario: Eat 5 out of 20
        Given there are 20 cucumbers
        When I eat 5 cucumbers
        Then I should have 15 cucumbers

Given、When、Then 高度重复，只是数据不一致而已
如何解决数据参数化的问题？就是通过 outlines

Scenario Outline: Eating
  Given there are <start> cucumbers
  When I eat <eat> cucumbers
  Then I should have <left> cucumbers
  Examples:
    | start | eat | left |
    |  12   |  5  |  7   |
    |  20   |  5  |  15  |

outline 重点

• Examples 的第一行不会被当做数据进行运行，从第二行开始读取数据并运行，一行代表一个测试场景
• 通过 <占位符>来表示变量参数，它可以卸载 Given、When、Then 步骤中

实际 🌰

outline.feature

Scenario Outline: Eating
  Given there are <start> cucumbers
  When I eat <eat> cucumbers
  Then I should have <left> cucumbers
  Examples:
    | start | eat | left |
    |  12   |  5  |  7   |
    |  20   |  5  |  15  |

test_outline.py

from pytest_bdd import given, then, parsers, scenarios, when
scenarios('outline.feature')
@given(parsers.parse("there are {start} cucumbers"))
def get_cucumbers(start):
    print(f"there ara {start} cucumbers")
    return start
@when(parsers.parse("I eat {eat} cucumbers"))
def eat_cucumbers(eat):
    print(f"I eat {eat} cucumbers")
    return eat
@then(parsers.parse("I should have {left} cucumbers"))
def left_cucumbers(left, eat, start):
    print(f"I should have {left} cucumbers")
    assert int(left) == (int(start) - int(eat))
    print("=== end ===")

命令行运行

pytest -sq test_outline.py

运行结果

there ara 12 cucumbers
I eat 5 cucumbers
I should have 7 cucumbers
=== end ===
.there ara 20 cucumbers
I eat 5 cucumbers
I should have 15 cucumbers
=== end ===
.
2 passed in 0.01s

可看到，收集了两个测试用例