Testing against python 3.15 using nox and uv

[Render Engine] is now testing against 3.15.

Our testing philosophy with render-engine is that we give people the ability to test as much as they can locally that will be tested on CI/CD.

Our way of doing this is via [nox] and [uv].

Nox supports UV natively

Nox makes it extremely easy to use uv. You can set it at runtime with the -fg uv flag. You can also use the venv_backend="uv" on your @nox.session decorator.

import nox

# we've added "3.15"
PYTHON_VERSIONS = ["3.15", "3.14", "3.13", "3.12", "3.11", "3.10"]

# `reuse` keeps the same .venv environment to prevent rebuilding each time
@nox.session(python=PYTHON_VERSIONS, venv_backend="uv", reuse_venv=True) 
def test(session: nox.Session) -> None:
    """Run the test suite"""
    session.run_install(
        "uv",
        "sync",
        "--dev",
        "--quiet",
        external=True,
    )
    session.run("pytest", "tests")

Adding 3.15 alphas/betas/rcs

With using uv you can add multiple python environments to your system directly with uv.

uv python 3.15.0b4 # do this for all the versions you're testing against

I used the exact version because when I tried simply 3.15 it added 3.15.0a7 and now. This could affect upgrading your environment.

You can quickly upgrade using uv python upgrade that will update all of the python versions.