Testing

For testing it is recommended to just switch to testing environment and read the same config files.

settings.toml

[default]
value = "On Default"

[testing]
value = "On Testing"

program.py

from dynaconf import settings

print(settings.VALUE)

ENV_FOR_DYNACONF=testing python program.py

Then your program.py will print "On Testing" red from [testing] environment.

Pytest

For pytest it is common to create fixtures to provide pre-configured settings object or to configure the settings before all the tests are collected.

Examples available on https://github.com/rochacbruno/dynaconf/tree/master/example/pytest_example

With pytest fixtures it is recommended to use the FORCE_ENV_FOR_DYNACONF isntead of just ENV_FOR_DYNACONF because it has precedence.

A python program

settings.toml with the [testing] environment.

[default]
VALUE = "On Default"

[testing]
VALUE = "On Testing"

app.py that reads that value from current environment.

from dynaconf import settings


def return_a_value():
    return settings.VALUE

tests/conftest.py with a fixture to force settings to run pointing to [testing] environment.

import pytest
from dynaconf import settings


@pytest.fixture(scope="session", autouse=True)
def set_test_settings():
    settings.configure(FORCE_ENV_FOR_DYNACONF="testing")

tests/test_dynaconf.py to assert that the correct environment is loaded

from app import return_a_value


def test_dynaconf_is_in_testing_env():
    assert return_a_value() == "On Testing"

A Flask program

settings.toml with the [testing] environment.

[default]
VALUE = "On Default"

[testing]
VALUE = "On Testing"

src.py that has a Flask application factory

from flask import Flask
from dynaconf.contrib import FlaskDynaconf


def create_app(**config):
    app = Flask(__name__)
    FlaskDynaconf(app, **config)
    return app

tests/conftest.py with a fixture to provide app dependency injection to all the tests, And force this app to point to [testing] config environment.

import pytest
from src import create_app


@pytest.fixture(scope="session")
def app():
    app = create_app(FORCE_ENV_FOR_DYNACONF="testing")
    return app

tests/test_flask_dynaconf.py to assert that the correct environment is loaded

def test_dynaconf_is_on_testing_env(app):
    assert app.config["VALUE"] == "On Testing"
    assert app.config.current_env == "testing"

Mocking

But it is common in unit tests to mock some objects and you may need in rare cases to mock the dynaconf.settings when running your tests.

from dynaconf.utils import DynaconfDict
mocked_settings = DynaconfDict({'FOO': 'BAR'})

DynaconfDict is a dict like obj that can be populated from a file:

from dynaconf.loaders import toml_loader
toml_loader.load(mocked_settings, filename='my_file.toml', env='testing')