Pytest：如何设置我的 pytest 配置（conftest）以在测试环境中运行？

Question

I thought the easy way was to reload the config module with my software environment as 'Testing'.

My code has a config.py which works as configuration handling code where I define all my configuration setting per each environment I'd like to run.

config.py

class Config(object):
    DEBUG = False
    TESTING = False
    DATABASE_URI = 'sqlite:///:memory:'

class ProductionConfig(Config):
    DATABASE_URI = 'mysql://user@localhost/foo'

class DevelopmentConfig(Config):
    DEBUG = True

class TestingConfig(Config):
    TESTING = True

config_lookup = dict(
    testing=TestingConfig(),
    development=DevelopmentConfig(),
    production=ProductionConfig(),
)

config = config_lookup[os.getenv('ENVIRONMENT', 'development')]

One approach could be using reload: On my conftest.py I would like to make ensure that all my tests would run as per TestingConfig. Therefore I would do something like this:

conftest.py

@pytest.fixture(autouse=True)
def cfg():
    # Reload the global 'config' instance.

    os.environ["ENVIRONMENT"] = "testing"
    importlib.reload(sys.modules["config"])

Unfortunately, this approach doesn't seem to work as expected for all situations as the importlib.reload() seems to perform expected.

importlib.reload() Reload a previously imported module. The argument must be a module object, so it must have been successfully imported before. Read more: importlib Docs

This solution may work in the first instance but it will become tricky when using a different type of imports.(object vs submodule)

An object is imported

from app.config import config 

print('Environment is:',type(config).__name__)

# Environment is:Development <- Wrong

An module is imported

import app.config as _ 

print('Environment is:',type(_.config).__name__)

# Environment is:Testing <-- correct

Another approach is to ensure you always set your environment variable when executing pytests: ENVIRONMENT=testing python -m pytest tests

Not a desirable as you might forget to append your environment.

Related issues:

difference-between-from-x-import-y-and-import-x-yPython Bug

Change environment variables before importlib.reload

Reloading All Loaded Modules

difference-between-from-x-import-y-and-import-xy pep-0221

Answer 1

Another approach that seems to work quite well is to ensure that you set your environment before running conftest.py . Is using python-env

[pytest]
env =
    ENVIRONMENT=testing

Seems to work fine. The upsidedown is that is an old repository without maintenance but is also a small piece of code.