Fail on invalid pyproject.toml dependencies sections?

[Nour-Mws]

This a follow-up to PR #351.
We currently support pyproject.toml files having both dynamic and static dependencies, including some states that are not valid. This is the case in the following example where optional-dependencies is flagged as dynamic then defined both in [tool.setuptools.dynamic] and in [project]. Attempting to pass this through setuptools will result in an error as soon as the line with the static definition of optional-dependencies is parsed.

We're not a pyproject.toml linter, but I feel uneasy making analysis on the basis of an invalid pyproject.toml.

I'm wondering if there's an easy way to source out this validation the way we've done with pip-requirements-parser?

[project]
name = "MyLib"
dynamic = ["optional-dependencies"]
dependencies = ["django"]
optional-dependencies = {"dev" = ["black"]}
[tool.setuptools.dynamic]
dependencies = { file = [".subdir/requirements.txt"] }
optional-dependencies.test = { file = [".subdir/requirements-test.txt"]