前言

pytest 运行完用例之后会生成一个 .pytest_cache 的缓存文件夹，用于记录用例的ids和上一次失败的用例。
方便我们在运行用例的时候加上–lf 和 –ff 参数，快速运行上一次失败的用例。
–lf, –last-failed 只重新运行上次运行失败的用例（或如果没有失败的话会全部跑）
–ff, –failed-first 运行所有测试，但首先运行上次运行失败的测试（这可能会重新测试，从而导致重复的fixture setup/teardown）

cache

pytest -h 查看命令行参数，关于 cache 参数的使用方式

> pytest -h
 
 --lf, --last-failed rerun only the tests that failed at the last 
 run (or all if none failed)
 --ff, --failed-first run all tests, but run the last failures first.
 This may re-order tests and thus lead to repeated fixture setup/teardown.
 --nf, --new-first run tests from new files first, then the rest of the tests sorted by file mtime
 --cache-show=[CACHESHOW]
 show cache contents, don't perform collection or tests. Optional argument: glob(default: '*').
 --cache-clear remove all cache contents at start of test run.

参数说明：

–lf 也可以使用 --last-failed 仅运行上一次失败的用例

–ff 也可以使用 --failed-first 运行全部的用例，但是上一次失败的用例先运行

–nf 也可以使用 --new-first 根据文件插件的时间，新的测试用例会先运行

–cache-show=[CACHESHOW] 显示.pytest_cache文件内容，不会收集用例也不会测试用例，选项参数: glob (默认: ‘*’)

–cache-show

案例

def test_01():
 a = "hello"
 b = "hello"
 assert a == b
 
 
 def test_02():
 a = "hello"
 b = "hello world"
 assert a == b
 
 
 def test_03():
 a = "hello"
 b = "hello world"
 assert a in b
 
 
 def test_04():
 a = "hello"
 b = "hello world"
 assert a not in b

命令行输入 运行完成后，会有2个用例失败，2个用例成功

collecting ... 
 case/test_1.py ✓ 25% ██▌ 
 
 case/test_1.py ⨯✓ 75% ███████▌ 
 
 case/test_1.py ⨯ 100% ██████████

运行完成后，会在当前的目录生成一个 .pytest_cache 的缓存文件夹,层级结构如下

lastfailed 文件记录上一次运行失败的用例

{
 "test_x.py::test_02": true,
 "test_x.py::test_04": true
 }

nodeids 文件记录所有用例的节点

[
 "test_x.py::test_01",
 "test_x.py::test_02",
 "test_x.py::test_03",
 "test_x.py::test_04"
 ]

于是可以通过 pytest –cache-show 命令查看cache目录

(pytest_env) ➜ apiAutomatic pytest --cache-show
 Test session starts (platform: darwin, Python 3.7.6, pytest 6.2.1, pytest-sugar 0.9.4)
 rootdir: /Users/jkc/PycharmProjects/apiAutomatic, configfile: pytest.ini
 plugins: assume-2.4.2, sugar-0.9.4, rerunfailures-9.1.1, base-url-1.4.2, html-3.1.1, metadata-1.11.0, ordering-0.6, cov-2.10.1, repeat-0.9.1, xdist-2.2.0, forked-1.3.0, allure-pytest-2.8.29
 cachedir: /Users/jkc/PycharmProjects/apiAutomatic/.pytest_cache
 ------------------------------------------------------------------------------------------------- cache values for '*' -------------------------------------------------------------------------------------------------
 cache/lastfailed contains:
 {'case/test_1.py::test_02': True, 'case/test_1.py::test_04': True}
 cache/nodeids contains:
 ['case/test_1.py::test_01',
 'case/test_1.py::test_02',
 'case/test_1.py::test_03',
 'case/test_1.py::test_04']
 cache/stepwise contains:
 []
 Results (0.02s):

–cache-clear

–cache-clear 用于在测试用例开始之前清空cache的内容

查看pytest关于cache的更多文档https://docs.pytest.org/en/latest/cache.html