new version-mode option for monorepo versioning

[dlqqq]

Problem

Right now, bump-version only offers one "versioning mode", a strategy to bump versions of all packages underneath the repository: running version-cmd inside of every Python package. Let us call this versioning mode per-python.

In monorepos such as Jupyter AI, we are using a single script that allows all package versions to be bumped with a single invocation run from the monorepo root. Without more configurability, the current behavior of Jupyter Releaser wastefully runs version-cmd for every Python package under the monorepo, rather than just running it once from the root.

Proposed Solution

Add a new version-mode option that allows two values: per-python and monorepo.

• version-mode is respected first. If set to per-python, it will ignore monorepo-specific options, and vice versa.

  • python_packages is a per-python version mode specific option, and will be ignored if version-mode is set to monorepo.
  • There are currently no monorepo specific options I suggest.

• When version-mode is set to per-python, the existing behavior is preserved.

• When version-mode is unspecified, we default to per-python.

• When version-mode is set to monorepo, then we only run version-cmd once at the repository root.

This proposal is also easily extensible. For example, if users wanted to run a command per Yarn workspace instead of per declared Python package, the solution would just involve adding a new versioning mode and its implementation.

Additional context

We are currently using lerna version to bump the NPM package versions and it works fairly well, though it has a lot of quirks. The killer feature is that it bumps versions of intra-monorepo dependencies. We're using hatch-nodejs-version to dynamically link the Python package version to the NPM package version.

[jtpio]

Maybe another approach would be to remove python_packages but still use version-cmd to bump the version (and have full control on it).

And use a custom script to build the Python packages and place them in the dist folder, so they can be picked up by the releaser in the next steps.