tox-min-req

Table of Contents

• Installation
• License
• Usage

tox-min-req is a tox plugin that simplifies
minimum requirements (min-req) testing.

Minimum requirements testing is important to validate whether the minimum requirements are satisfied.

After installing, to use this plugin you need to use MIN_REQ environment variable either in the call (e.g. MIN_REQ=1 tox -e py38-linux-pyqt5) or in setenv section of your tox configuration.

Why use this instead of deps attribute of the tox env section?

One alternative solution is to use the deps section in tox configuration to install min-req dependecies.

However, packages from deps and the actual package to be tested are installed in two independent steps. This means that some of the min-req dependencies could be upgraded or downgraded when installing the actual package.

The PIP_CONSTRAINT and UV_CONSTRAINT variables are used to pin the dependencies; it will apply to the call of pip install during dependency resolving.

Installation

pip install tox-min-req

License

tox-min-req is distributed under the terms of the MIT license.

Usage

The basic usage is to set the MIN_REQ environment variable to 1

$ MIN_REQ=1 tox -e py37

Configuration options

The tox-min-req plugin allows one to provide the following environment configuration options:

• min_req - set to 1 to enable the minimum requirements testing; can be used instead of setting the environment variable.
• min_req_constraints - list of additional constraints that will be used to generate the constraints file. This is useful in following scenarios:
  • Some of dependencies of an old version are incompatible with dependencies in latest version (see Known issues, below).
  • Maintainers would like to also test some problematic dependencies an old version, but not the oldest supported version.

[tox]
envlist = py310

[testenv]
extras = test
recreate = True
commands = pytest test_file.py
min_req = 1
min_req_constraints=
    coverage==6.5.0
    babel==2.6.0
    six==1.14.0
    -r {project_dir}/constraints.txt

Please note that -r {project_dir}/constraints.txt will be put in the generated constraints file—it will not be parsed.

Known issues

Pinning only direct dependencies

Because this plugin only parses setup.cfg or pyproject.toml files, it is not possible to pin any indirect dependencies. To pin indirect dependencies, the min_req_constraints environment configuration option should be used.

Spaces in the constraints file path

pip uses spaces as file path separators in the PIP_CONSTRAINT variable. This plugin stores the generated constraints file in a .tox temporary directory. As a result, if the path to the temporary directory contains spaces, then pip will not be able to find the constraints file.

In such a scenatio, one needs to set the TOX_MIN_REQ_CONSTRAINTS environment variable to the path where constraints file can be written.

$ TOX_MIN_REQ_CONSTRAINTS=/tmp MIN_REQ=1 tox -e py37

It is also possible to use the --min-req-constraints-path command line option to set the path to the constraints file.

$ tox --min-req-constraints-path=/tmp -e py37