Testing project.optional-dependencies without duplicating dependencies

[topherbuckley]

I'm sure I'm misunderstanding something here, but I just want to have two hatch envs, call them release and debug as an example. I want users to be able to install a different list of dependencies for each (e.g. pip install example-package[debug] vs pip install example-package[release], and I want to use hatch to test that my package passes some basic tests using these exact same dependencies. For example:

[build-system]
requires = ["hatchling"]
build-backend = "hatchling.build"

[project]
name = "example-package"
description = "An example Python package"
authors = [{ name = "Your Name", email = "your.email@example.com" }]
license = { file = "LICENSE" }

[project.optional-dependencies]
release = [
    "requests>=2.25,<3.0",  
    "numpy>=1.20,<2.0",     
]
debug = [
    "requests>=2.25,<3.0",
    "numpy>=1.20,<2.0",
    "pytest>=6.0,<7.0",     
]

[tool.hatch]
envs = { 
    release = { dependencies = ["requests>=2.25,<3.0", "numpy>=1.20,<2.0"] },
    debug = { dependencies = ["requests>=2.25,<3.0", "numpy>=1.20,<2.0", "pytest>=6.0,<7.0"] }
}

Do I really need to specify the dependencies and versions in two separate places like this? Am I fundamentally misunderstanding something here? I found a similar discussion here but no resolution.

[tayfuryldz]

You can avoid duplicating the package's optional-dependency lists. Hatch environments have a features option specifically for installing the project's extras.

With the metadata in the question, the environments can be:

[project.optional-dependencies]
release = [
    "requests>=2.25,<3.0",
    "numpy>=1.20,<2.0",
]
debug = [
    "requests>=2.25,<3.0",
    "numpy>=1.20,<2.0",
    "pytest>=6.0,<7.0",
]

[tool.hatch.envs.release]
features = ["release"]

[tool.hatch.envs.debug]
features = ["debug"]

Current Hatch documents features as the environment setting that selects groups from project.optional-dependencies (extras). The project is installed into the environment with the selected feature(s), so those dependency specifications remain defined once in package metadata.

If pytest is only tooling needed to execute the test suite and is not something consumers should receive from pip install example-package[debug], I would separate that concern instead:

[tool.hatch.envs.debug]
features = ["debug"]
extra-dependencies = ["pytest>=6,<7"]

That distinction is useful: project.optional-dependencies describes installable public extras of the package, while an environment's dependencies/extra-dependencies are development/test-environment requirements.

So for the stated goal — test the same extras users install — features = ["release"] and features = ["debug"] are the direct Hatch mechanism; there is no need to copy the version constraints into the environment definitions.