Intro

Yellowbox is a library for making it easy to blackbox-test your code by setting up all the dependencies your program would need. Say your program requires connection to a redis database, a postgresql database, and an HTTP server. You can use yellowbox to set up all of these dependencies for you.

from yellowbox import docker_client
from yellowbox.extras.redis import RedisService
from yellowbox.extras.postgresql import PostgreSQLService
from yellowbox.extras.webserver import WebServer

from starlette.responses import PlainTextResponse

# Create a new docker client
with docker_client() as client,\  # get a client to interface with docker
    RedisService.run(client) as redis,\  # start a redis docker container
    PostgreSQLService.run(client) as postgres,\  # start a postgresql docker container
    Webserver("math-service").start() as math_server:  # start a local HTTP server

    # Add a constant route to the webserver
    math_server.add_http_route('GET', '/api/v1/pi', PlainTextResponse("3.1415"))

    # now your app can be started with all the dependencies it needs
    app = MyApp(redis_url = 'localhost', redis_port = redis.client_port(),
                postgres_conn_string = postgres.local_connection_string(),
                math = math_server.local_url())


    app.run()

Yellowbox can be used seamlessly with pytest fixtures

from pytest import fixture

from yellowbox import docker_client as _docker_client
from yellowbox.extras.redis import RedisService
from yellowbox.extras.postgresql import PostgreSQLService
from yellowbox.extras.webserver import WebServer

from starlette.responses import PlainTextResponse

# docker_client is a fixture automatically added by yellowbox

@fixture(scope='session')
def redis(docker_client):
    with RedisService.run(docker_client) as redis:
        yield redis

@fixture(scope='session')
def postgresql(docker_client):
    with PostgreSQLService.run(docker_client) as postgres:
        yield postgres

@fixture(scope='session')
def math_server():
    with Webserver("math-service").start() as math_server:
        math_server.add_http_route('GET', '/api/v1/pi', PlainTextResponse("3.1415"))
        yield math_server


@fixture
def app(redis, postgres, math_server):
    app = MyApp(redis_url = 'localhost', redis_port = redis.client_port(),
                postgres_conn_string = postgres.local_connection_string(),
                math = math_server.local_url())
    return app

# you can now use the "app" fixture in your tests and get a fully-functional application

Yellowbox comes with built-in services for many popular infras, such as PostgreSQL, Redis, and RabbitMQ, and also has a comprehensive, easy-to-use library to create your own services for whatever your app needs.

Use Yellowbox if:

• Your program requires other services to be running, such as a database, a webserver, a message queue, or a message broker.

• You want to test your program’s ability to connect to these services.

• You want to test your program’s connection to these services.

• You want the tests to easily integrate with your existing testing infrastructure. Making it easy to run these tests both locally and remotely in CI/CD.