pico-testing 0.2.0

Pytest plugin for the Pico ecosystem: isolated containers by default and a make_container fixture.

pico-testing

Pytest plugin for the pico ecosystem: isolated containers by default and a make_container fixture with automatic shutdown.

Why

Any pico_boot.init() in a test auto-discovers every pico plugin installed in the venv — so a test suite passes or fails depending on what else happens to be installed. Every pico project ends up copying the same two conftest fixtures. This plugin ships them once:

• Isolation by default: PICO_BOOT_AUTO_PLUGINS=false is set for every test. Opt back in per-test with @pytest.mark.pico_auto_plugins.
• make_container: builds containers from explicit modules and config, and shuts them all down on teardown.
• pico_module: declare the package under test once in your pytest config; make_container() always includes it.
• make_client: a FastAPI TestClient over a container's app, with the lifespan running and a safe close on teardown.

Installation

pip install pico-testing

No conftest wiring — installing it activates the plugin.

Quick start

import sys

def test_my_service(make_container):
    container = make_container(
        "my_package",
        config={"my_prefix": {"key": "value"}},
    )
    service = container.get(MyService)
    assert service.do_something() == "expected"

make_container(*modules, config=None, boot=False):

• modules: module objects or import strings, passed to init(modules=[...]).
• config: a plain dict (wrapped in configuration(DictSource(...))) or a ready configuration(...) object.
• boot=True: use pico_boot.init instead of pico_ioc.init (plugin auto-discovery still off unless the test is marked).

Re-enable plugin auto-discovery for a single test:

import pytest

@pytest.mark.pico_auto_plugins
def test_full_boot(make_container):
    container = make_container(boot=True)

Module under test

Declare it once and drop it from every call:

# pyproject.toml
[tool.pytest.ini_options]
pico_module = "my_package"

def test_my_service(make_container):
    service = make_container().get(MyService)

Testing HTTP endpoints

With pico-fastapi installed, make_client wraps the container's app in a TestClient with the lifespan running (requires pico-ioc >= 2.3.3):

def test_endpoint(make_container, make_client):
    container = make_container("pico_fastapi", config={"fastapi": {"title": "t"}})
    client = make_client(container)
    assert client.get("/ping").status_code == 200

Documentation

Full documentation: https://dperezcabrera.github.io/pico-testing/

AI Coding Skills

Install Claude Code or OpenAI Codex skills for AI-assisted development with pico-testing:

curl -sL https://raw.githubusercontent.com/dperezcabrera/pico-skills/main/install.sh | bash

The pico-conventions skill teaches the assistant this module's API surface and invariants; /add-component and /add-tests scaffold components and tests that use it.

License

MIT