plan.md

Plan for adding uv.lock support to pip.parse

Part 1: Analyze and Plan (Done)

• Analyzed python/extensions/pip.bzl, python/private/pypi/hub_builder.bzl, python/private/pypi/uv_lock.bzl.
• Confirmed uv.lock structure contains wheel URLs and resolution markers.
• Identified need to modify pip_repository_attrs.bzl and hub_builder.bzl.

Part 2: Basic Implementation

1. Modify python/private/pypi/pip_repository_attrs.bzl:

   • Add uv_lock attribute (label, allow_single_file=True).
   • Add _toml2json attribute (label, default pointing to a tool). Note: Need to verify if _toml2json is already available or needs to be added. The uv_lock.bzl helper uses attr._toml2json, so it must be present on the calling rule/tag.

2. Modify python/private/pypi/hub_builder.bzl:

   • In _pip_parse:
     • Check if pip_attr.uv_lock is set.
     • If set, call convert_uv_lock_to_json.
     • Parse the JSON result.
     • Iterate over packages in the JSON.
     • Group packages by name.
     • For this step, select the highest version for each package name.
     • Select the first wheel URL for that version.
     • Create whl_library repositories for these wheels.
     • Ensure these whl_library calls are integrated into self._whl_libraries.

3. Verify:

   • Run bazel run //tests/uv_pypi:bin.

Part 3: Advanced Implementation (Multiple Versions)

1. Handle Resolution Markers:

   • Parse resolution-markers from uv.lock packages.
   • Instead of picking one version, keep all versions that have distinct resolution markers.

2. Use wheel_tags_settings:

   • In hub_builder.bzl, when constructing the hub repository content (via hub_repository), we need to pass information about these multiple versions.
   • The hub_repository rule (or the macros creating it) needs to generate define_wheel_tag_settings in the BUILD.bazel of the hub.
   • Generate alias targets using select() based on the defined settings.

3. Refactor Hub Generation:

   • Update hub_repository.bzl (or the template it uses) to support this new "multi-version via select" pattern, if it doesn't already. The prompt suggests modifying the "hub build file for a package".

4. Verify:

   • Run the test again. It should correctly pick absl-py 2.3.1 or 2.4.0 based on the environment/platform.