Helly25 bzl, a Bazel support library

This library provides Bazel Starlark functionality meant to help in maintaining other libraries.

Versions

Implements versioning functions that mostly follow Semver.

Comparators correctly respect major, minor and patch components, as well as Semver compliant 'pre-release' and 'build' components. The pre-release and build components are split at ".". Comparing pre-release parts works for alphabetical prefixes and numeric suffixes, so 'alpha', 'beta' and 'rc' as well as numbered version of those (e.g. 'alpha1' or rc-1') are supported. For pre-releases and build pieces a single '-' in front of the numeric parts is dropped (e.g. 'rc-1' becomes 'rc' + '1' while 'alpha--2' becomes 'alpha-' + '2').

The full functionality is exposed as a singele struct containing all functions.

The version parameters support:

• a string that can be parsed according to: major['.' minor [ '.' patch [ '.' digits]*]] ['-' [^+]+] ['+' .*]
• a list or tuple where each component is a version part. If present, then:
  • a pre-release component must be separated by a single "-" and split by ".".
  • a build component must be separated by a single "+" and split by "."
• a single int which will be the major version.
• anything else is an error and the functions will fail.
• unlike Semver, the function allows any number of numeric version components.

Note: Most functions support a skip_build parameter. If True, then any present build component will be dropped. Conclusively the parameter is True by default for parsing and False for comparisons since Semver dictates that that the build component must be ignored for precedence (see Semver-10).

The functionality has exhaustive tests. If something still works wrong please, file a bug report or propose a fix.

Example:

my_version = "25.33.42"
min_version = (10, 11, 12)
if _versions.lt(my_version, min_version):
  fail("My version {my_version} is earlier than {min_version}.".format(
    my_version = my_version,
    min_version = min_version,
  ))

Provides:

• load("@helly25_bzl//bzl/versions:versions_bzl", _versions = "versions")
  • versions is a single import structure:
    • parse: Parses a version.
    • ge: Implements L >= R.
    • gt: Implements L > R.
    • le: Implements L <= R.
    • lt: Implements L < R.
    • eq: Implements L == R.
    • ne: Implements L != R.
    • cmp: Implements L <=> R aka (L < R) - (L > R).
    • compare: Implements L OP R.
    • check_one_requirement: Checks a version adheres to a single requirement.
    • check_all_requirements: Checks a version adheres to a requirements list.
    • parse_requirements: Parses a requirements specification.

Installation

The library is available for both Bazelmod and Workspace installations and works on MacOS, Ubuntu and Windows with Bazel version 7.x and 8.x (Other systems are simply not tested). However future version may drop Windows support.

For MODULES.bazel

See https://github.com/helly25/bzl/releases to replace the version number.

bazel_dep(name = "helly25_bzl", version = "0.0.0")

For WORKSPACE

load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")

http_archive(
  name = "helly25_bzl",
  url = "https://github.com/helly25/bzl/releases/download/0.0.0/bzl-0.0.0.tar.gz",
  sha256 = "...." # see https://github.com/helly25/bzl/releases for version numbers SHA256 codes.
)

Dependencies

• bazel_skylib.