noxfile.py

"""
Nox sessions, which each run in an isolated Python environment with
minimal dependencies. This ensures that we never accidentally depend
on dev dependencies in production code (thus, we achieve a feature
similar to Maven's dependency scopes).
"""

import os
import subprocess
from tempfile import NamedTemporaryFile
from typing import Any

import nox
from nox.sessions import Session

PYTHON_VERSIONS = ["3.9", "3.10"]

nox.needs_version = ">=2021.10.1"
nox.options.sessions = ["lint", "tests"]
nox.options.stop_on_first_error = True


def install_with_constraints(session: Session, *args: str, **kwargs: Any) -> None:
    """Install packages constrained by poetry's lockfile."""
    with NamedTemporaryFile() as constraints:
        # This approach is by Claudio Jolowicz, see his excellect
        # example at github.com/cjolowicz/hypermodern-python.
        session.run(
            "poetry",
            "export",
            "--with",
            "dev",
            "--without-hashes",
            "--format=constraints.txt",
            f"--output={constraints.name}",
            external=True,
        )
        session.install(f"--constraint={constraints.name}", *args, **kwargs)


def is_docker_running() -> bool:
    """Check if the Docker daemon is running."""
    args = ["docker", "info"]
    result = subprocess.run(args, stdout=subprocess.DEVNULL, stderr=subprocess.DEVNULL)
    return result.returncode == 0


def build_docker_image(session: Session) -> None:
    """Build the image required by our docker integration tests."""
    session.run(
        "docker",
        "build",
        "--tag",
        "inloop-integration-test",
        "tests/testrunner",
        external=True,
    )


def poetry_install(session: Session) -> None:
    """Install the runtime dependencies with poetry."""
    session.run("poetry", "install", "--only", "main", external=True)


@nox.session(python=PYTHON_VERSIONS)
def tests(session: Session) -> None:
    """Run the complete test suite without dev dependencies."""
    args = session.posargs or ["-v2", "--failfast"]
    if is_docker_running():
        build_docker_image(session)
    elif "CI" in os.environ:
        session.error("Docker daemon is not running")
    else:
        args.append("--exclude-tag=needs-docker")
        session.warn("Docker daemon is not running, skipping docker tests")
    poetry_install(session)
    install_with_constraints(session, "coverage[toml]")
    session.run("coverage", "run", "./runtests.py", "--", *args)
    session.run("coverage", "report")


@nox.session(python=PYTHON_VERSIONS)
def lint(session: Session) -> None:
    """Check code style with flake8 and isort."""
    locations = "inloop", "tests", "noxfile.py", "manage.py", "runtests.py"
    install_with_constraints(
        session,
        "flake8",
        "flake8-annotations",
        "flake8-black",
        "flake8-bugbear",
        "flake8-docstrings",
        "flake8-isort",
    )
    session.run("flake8", *locations)


@nox.session(python=PYTHON_VERSIONS)
def pytype(session: Session) -> None:
    """Statically check for type errors with pytype."""
    args = session.posargs or ["--config", "pytype.cfg"]
    poetry_install(session)
    install_with_constraints(session, "pytype")
    session.run("pytype", *args)


@nox.session(python=PYTHON_VERSIONS)
def typeguard(session: Session) -> None:
    """Run the test suite with run-time type checking of PEP-484 annotations."""
    args = session.posargs or ["-v2", "--failfast"]
    build_docker_image(session)
    poetry_install(session)
    install_with_constraints(session, "typeguard")
    session.run("python", "runtests.py", "--with-typeguard", "--", *args)