pubupgrade: Combine your dart pubspec files' information so that you can easily upgrade your pubspec.yaml to the versions in your pubspec.lock

pubupgrade.py

#!/usr/bin/env python
# -*- coding: utf-8 -*-
from __future__ import print_function

import argparse
import sys
import re

import yaml  # PyYAML


def merge(yamlfile, lockfile, outf=None, comment_previous_version=False,
          include_dev=True, only_upgrade=True):
    """

    """
    lock_data = yaml.safe_load(lockfile)
    lock_versions_by_package_name = {
        name: details['version'] for name, details in lock_data['packages'].items()
    }
    print('lock_versions_by_package_name')
    print(lock_versions_by_package_name)

    yaml_data = yaml.safe_load(yamlfile)
    dep_versions_by_package_name = {
        name: details['version'] if isinstance(details, dict) and details.get(
            'version') else details for name, details in yaml_data['dependencies'].items()
    }
    print('dep_versions_by_package_name')
    print(dep_versions_by_package_name)

    # dev_dependencies are optional
    if include_dev:
        dev_dep_versions_by_package_name = {
            name: details['version'] if isinstance(details, dict) and details.get(
                'version') else details for name, details in yaml_data['dev_dependencies'].items()
        }
        print('dev_dep_versions_by_package_name')
        print(dev_dep_versions_by_package_name)

        dep_versions_by_package_name.update(dev_dep_versions_by_package_name)

    def get_replacement(line, maybe_package, new_version):
        previous_version = dep_versions_by_package_name.get(maybe_package)  # type: str
        if not previous_version:
            return line

        if isinstance(previous_version, dict):
            # Likely a path dep; nothing to do
            return line

        if '>' in previous_version:
            is_gte = '>=' in previous_version
            equals_or_blank = '=' if is_gte else ''
            if '<' in previous_version:
                # upper_range includes the equals sign if present
                upper_range = re.sub(r'.*?<([^ #]+)', r'\1', previous_version)
                new_version = '>{}{} <{}'.format(equals_or_blank, new_version, upper_range)
            else:
                new_version = '>{}{}'.format(equals_or_blank, new_version)
        else:
            new_version = '^{}'.format(new_version)
        addendum = ''
        if previous_version != new_version and comment_previous_version:
            addendum = '  # was {}'.format(previous_version)
        replacement = line.replace(previous_version, new_version).replace(
            '\n', '{}\n'.format(addendum)
        )
        return replacement

    outf = outf or open('{}.updated'.format(yamlfile.name), 'w')
    yamlfile.seek(0)
    looking_for_version_key = False
    maybe_package = None
    new_version = None
    for line in yamlfile:
        if looking_for_version_key:
            if 'version' in line:
                looking_for_version_key = False
                outf.write(get_replacement(line, maybe_package, new_version))
            else:
                outf.write(line)
            continue

        maybe_package_and_version = line.strip().split(':')
        maybe_package = maybe_package_and_version[0]
        # TODO might need to strip out known keys that could be package names, e.g. 'path', 'url'
        new_version = lock_versions_by_package_name.get(maybe_package)
        if new_version:
            package_and_version_on_same_line = len(maybe_package_and_version) == 2 and \
                                               maybe_package_and_version[
                                                   1]  # can't be empty either
            if package_and_version_on_same_line:
                outf.write(get_replacement(line, maybe_package, new_version))
            else:
                looking_for_version_key = True
                outf.write(line)
                continue
        else:
            outf.write(line)


if __name__ == '__main__':
    parser = argparse.ArgumentParser(
        description='Copy version numbers from pubspec.lock to pubspec.yaml.'
    )
    parser.add_argument(
        'yaml', type=argparse.FileType('r'),
        help='path to pubspec.yaml file'
    )
    parser.add_argument(
        'lock', type=argparse.FileType('r'),
        help='path to pubspec.lock file'
    )
    parser.add_argument(
        '--out', '-o', default=sys.stdout, type=argparse.FileType('w'),
        help='file where the merged output should go'
    )
    parser.add_argument(
        '--comment-previous-version', '-p', default=False, action='store_true',
        help='includes the previous version as a code comment (default=false)'
    )
    parser.add_argument(
        '--no-include-dev', dest='include_dev', default=False, action='store_false',
        help='also upgrades dev dependencies (default=true)'
    )

    # TODO
    # parser.add_argument(
    #     '--only-upgrade', '-u', default=True, type=bool,
    #     help='disallows downgrading deps'
    # )

    args = parser.parse_args()
    merge(
        args.yaml, args.lock,
        outf=args.out,
        comment_previous_version=args.comment_previous_version,
        include_dev=args.include_dev,
        # args.only_upgrade,
    )

TIL that WP-5884 pubspec.yaml updater by toddbeckman-wf · Pull Request #1 · Workiva/pubspec_up was a thing!

Also INTRISK-28877: SyncDeps Command by matthewnitschke-wk · Pull Request #21 · Workiva/pub-tool