Add support for editable dependencies

[RobertRosca]

Rough implementation of editable dependencies as described in #588

This could probably be implemented in a better way, just a proof of concept.

[BrutalSimplicity]

Nice work here. I'm looking into this as well, but through the amazing plugin architecture Hatch provides.

Question, will this handle transitive editable dependencies?

[RobertRosca]

Internally these requirements get parsed a bit and then passed on to pip, so the behaviour is identical to what would happen if you manually installed a dependency as editable. Meaning that if you have a scenario like:

[tool.hatch.envs.dev]
dependencies = [
  "-e pkg_a @ {root:uri}/plugins/pkg_a",
  "-e pkg_a_dep @ {root:uri}/plugins/pkg_a_dep",
  ...
]

Then pkg_a_dep would be installed in editable mode, and pkg_a would then use that editable installation.

[BrutalSimplicity]

Okay. So the transitive editable dependencies would also need to be specified explicitly.

It would be great if it could infer the transitive dependency's editable packages in some way.

[ofek]

Hey, sorry I didn't respond sooner! I've been embedding on a different team for the past 3 weeks (1 more to go).

One thing I realized during this time was that rather than this approach, I'm going to implement functionality similar to Rust's workspace concept:

• https://doc.rust-lang.org/book/ch14-03-cargo-workspaces.html
• https://doc.rust-lang.org/cargo/reference/workspaces.html

[RobertRosca]

No problem! That sounds interesting, I'm happy to contribute if you'd like any help.

[webknjaz]

@RobertRosca this PR needs rebasing to pick up the CI updates.

[ofek]

Closing for now #589 (comment)

[ystarikovich]

Hey, @ofek do you have some issue to track on the current topic? Do you need some support with the implementation of it? We are missing this feature quite a lot