Use Jinja templating on styles

[andreoliwa]

Problem

Enforce configuration values that depend on variables. E.g.: a string that is used in every project, only changing the project name.

Possible solution

• [ ] Allow Jinja templating on configuration values
• [ ] Accept references to environment variables, e.g {{ env.MY_VAR }}
• [ ] Accept references to other configurations in other files, e.g. {{ file["pyproject.toml"].tool.poetry.name }} or {{ pyproject_toml.tool.poetry.name }}
• [ ] Reference setup.cfg, e.g. {{ setup_cfg.isort.skip }}
• [ ] Set isort line length from black

  ["setup.cfg".isort]
  line_length = {{ pyproject_toml.tool.black["line-length"] }}

• [ ] Verify which syntax will work: dots, underscores, dictionary key access...

[valberg]

I'm running into this "problem" right now. I have several projects which I want to add mypy configuration to, and the projects have different values for mypy_path.

One solution would of course streamline the projects to have src directories for mypy to look in. But having some way of defining variables would be very neat.