Title: Ensuring Test Mode with Pytest: Configuration and Testing Guide

Table of Contents:

1. Introduction
2. Modifying conftest.py
3. Creating test_general.py
4. Creating test_config.py
5. Test Cases
6. Conclusion

Introduction:
To ensure that our project runs in test mode each time we use Pytest, we need to configure it accordingly. In this section, we'll walk through the necessary steps to set up the project for test mode and create tests to verify its behavior. Let's get started!

Modifying conftest.py:
In the conftest.py file located at the root of your project, add the following code snippet. This code sets the RUN_MODE environment variable to "test" whenever Pytest is run, ensuring that our project runs in test mode during testing.

import os

def pytest_configure(config):
    os.environ["RUN_MODE"] = "test"

Creating test_general.py:
Create a new file called test_general.py in the tests folder and add the provided code snippet. This test verifies that the project is running in test mode by checking the value of the RUN_MODE environment variable.

import os

def test_run_mode_value_at_run_time():
    assert os.environ["RUN_MODE"] == "test"

Creating test_config.py:
Create another file called test_config.py in the tests folder and add the following code snippets. This file includes multiple test cases to validate different aspects of the Config class:

import os
from config import Config

def test_config_singleton():
    config1 = Config()
    config2 = Config()
    assert config1 is config2


def test_config_default_values():
    os.environ.pop("RABBITMQ_HOST", None)
    os.environ.pop("RABBITMQ_PORT", None)
    os.environ.pop("RABBITMQ_USER", None)
    os.environ.pop("RABBITMQ_PASSWORD", None)
    os.environ.pop("RABBITMQ_VHOST", None)
    os.environ.pop("RUN_MODE", None)

    config = Config(load_from_file=False, override=True)
    assert config.RABBITMQ_HOST == "localhost"
    assert config.RABBITMQ_PORT == 5672
    assert config.RABBITMQ_USER == "admin"
    assert config.RABBITMQ_PASSWORD == "admin"
    assert config.RABBITMQ_VHOST == "localhost"
    assert config.RUN_MODE == "debug"

    os.environ["RUN_MODE"] = "test"


def test_is_test_mode():
    config = Config(override=True)

    config.RUN_MODE = "test"
    assert config.is_test_mode() is True

    config.RUN_MODE = "debug"
    assert config.is_test_mode() is False

    config.RUN_MODE = "prod"
    assert config.is_test_mode() is False

    config.RUN_MODE = "test"


def test_is_debug_mode():
    config = Config(override=True)

    config.RUN_MODE = "test"
    assert config.is_debug_mode() is False

    config.RUN_MODE = "debug"
    assert config.is_debug_mode() is True

    config.RUN_MODE = "prod"
    assert config.is_debug_mode() is False

    config.RUN_MODE = "test"


def test_waiting_factor():
    config = Config(override=True)

    config.RUN_MODE = "test"
    assert config.waiting_factor() == 0

    config.RUN_MODE = "debug"
    assert config.waiting_factor() == 2

    config.RUN_MODE = "prod"
    assert config.waiting_factor() == 2

    config.RUN_MODE = "test"

Test Cases:

1. Test Case: test_config_singleton()

   • This test verifies that the Config class follows the Singleton design pattern.
   • It creates two instances of the Config class, config1 and config2, and asserts that they are the same object (config1 is config2).
   • By ensuring that both instances refer to the same object, we confirm that only one instance of the Config class exists, as expected for a Singleton.

2. Test Case: test_config_default_values()

   • This test checks if the default values of the Config class are correctly set when certain environment variables are not defined.
   • It removes specific environment variables related to RabbitMQ configuration and the RUN_MODE from the environment.
   • Then, it creates an instance of the Config class with load_from_file set to False and override set to True.
   • The test asserts that the instance's attributes (config.RABBITMQ_HOST, config.RABBITMQ_PORT, etc.) are set to their expected default values.
   • These expected default values are "localhost" for RABBITMQ_HOST, 5672 for RABBITMQ_PORT, "admin" for RABBITMQ_USER and RABBITMQ_PASSWORD, and "debug" for RUN_MODE.
   • Finally, it sets RUN_MODE to "test" in the environment for further test cases that rely on it.

3. Test Case: test_is_test_mode()

   • This test checks if the is_test_mode() method of the Config class correctly determines whether the project is running in test mode.
   • It creates an instance of the Config class with override set to True.
   • The test sets the RUN_MODE attribute to different values ("test", "debug", "prod") and asserts the return values of is_test_mode() accordingly.
   • It expects is_test_mode() to return True when RUN_MODE is set to "test" and False for other modes.

4. Test Case: test_is_debug_mode()

   • Similar to the previous test case, this test checks if the is_debug_mode() method of the Config class correctly determines whether the project is running in debug mode.
   • It creates an instance of the Config class with override set to True.
   • The test sets the RUN_MODE attribute to different values ("test", "debug", "prod") and asserts the return values of is_debug_mode() accordingly.
   • It expects is_debug_mode() to return True when RUN_MODE is set to "debug" and False for other modes.

5. Test Case: test_waiting_factor()

   • This test verifies the behavior of the waiting_factor() method of the Config class.
   • It creates an instance of the Config class with override set to True.
   • The test sets the RUN_MODE attribute to different values ("test", "debug", "prod") and asserts the return values of waiting_factor() accordingly.
   • It expects waiting_factor() to return 0 when RUN_MODE is set to "test" and 2 for other modes.

Conclusion:
With the configuration and tests in place, your project is now set up to run in test mode during Pytest execution. The added tests validate that the project is indeed running in test mode, that the Config class behaves as expected, and that the default values are correctly assigned. This ensures the reliability and correctness of your testing environment. You're now ready to run Pytest and enjoy the benefits of a well-configured and thoroughly tested project. Happy testing!