https://github.com/wemake-services/pytest-modified-env

Pytest plugin to fail a test if it leaves modified `os.environ` afterwards.
https://github.com/wemake-services/pytest-modified-env

codequality pytest pytest-plugin python3 test testing tests unittest

Last synced: about 2 months ago
JSON representation

Pytest plugin to fail a test if it leaves modified `os.environ` afterwards.

• Host: GitHub
• URL: https://github.com/wemake-services/pytest-modified-env
• Owner: wemake-services
• License: mit
• Created: 2022-01-29T09:22:52.000Z (over 3 years ago)
• Default Branch: master
• Last Pushed: 2025-03-03T06:07:21.000Z (3 months ago)
• Last Synced: 2025-04-12T09:30:52.105Z (2 months ago)
• Topics: codequality, pytest, pytest-plugin, python3, test, testing, tests, unittest
• Language: Python
• Homepage: https://pypi.org/project/pytest-modified-env/
• Size: 213 KB
• Stars: 13
• Watchers: 2
• Forks: 0
• Open Issues: 1
• Metadata Files:
  • Readme: README.md
  • Changelog: CHANGELOG.md
  • Contributing: CONTRIBUTING.md
  • License: LICENSE

Awesome Lists containing this project

• awesome-pytest - pytest-modified-env - Pytest plugin to fail a test if it leaves modified `os.environ` afterwards. (Plugins)

README

        
# pytest-modified-env

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Pytest plugin to fail a test if it leaves modified `os.environ` afterwards.

Example:

```python

import os

def test_that_modifies_env() -> None:

    os.environ['CUSTOM_ENV'] = '1'

```

With `pytest-modified-env` plugin installed, this test will fail:

```

___________________________ test_that_modifies_env ____________________________

test_that_modifies_env:4: in pytest_runtest_call

E   RuntimeError: os.environ was changed

```

Because it adds `CUSTOM_ENV` inside a test and does not clean it up.

In theory it can affect other tests and tests should be isolated!

## Installation

```bash

pip install pytest-modified-env

```

## Extras

In some cases test still might modify the env in this way. 

But, it needs an explicit approval for that:

```python

import os

import pytest

@pytest.mark.modify_env()

def test_that_modifies_env() -> None:

    os.environ['CUSTOM_ENV'] = '1'

```

This test won't fail, eventhough it adds `CUSTOM_ENV`,

because it has `modifies_env` marker.

## License

[MIT](https://github.com/wemake-services/pytest-modified-env/blob/master/LICENSE)