garden.py

import argparse
import json
import subprocess
from collections import namedtuple


def execute(arg, cwd):
    proc = subprocess.Popen(
        arg,
        shell=True,
        cwd=cwd,
        stdout=subprocess.PIPE,
        stderr=subprocess.PIPE)
    return proc.communicate()


class Package(namedtuple(
    'Package',
    ['name', 'current', 'wanted', 'latest', 'type', 'url'])
):
    def __eq__(self, other):
        def f(x):
            return ':'.join([x.name, x.current, x.latest])
        return f(self) == f(other)


def print_table(packages):
    longest = max([len(x.name) for x in packages])
    fmt = '{p.name:<{width}} {p.current} -> {p.latest}'
    print('```')
    for p in packages:
        print(fmt.format(width=longest, p=p))
    print('```')
    print()


def get_packages(path):
    (out, err) = execute('yarn outdated --json', cwd=path)
#    if err:
#        raise Exception(err)

    entries = [json.loads(x) for x in out.split(b'\n') if x]
    tables = [x for x in entries if x['type'] == 'table']
    assert len(tables) == 1, 'yarn outdated has multiple tables'

    packages = [Package(*x) for x in tables[0]['data']['body']]
    return packages


def parse_args():
    parser = argparse.ArgumentParser(description='Listing up the target packages for gardening.')
    parser.add_argument('paths', type=str, nargs='*', help='target paths')
    return parser.parse_args()


if __name__ == '__main__':
    args = parse_args()
    unique_packages = []
    print('## projects')
    print()
    for path in args.paths:
        packages = get_packages(path)
        print('### %s' % path)
        print_table(packages)
        [unique_packages.append(x) for x in packages
            if x not in unique_packages]
    print('## unique packages')
    sorted_packages = sorted(unique_packages)
    print_table(sorted_packages)

    changelogs = json.loads(open('./ui/changelogs.json').read())
    for package in sorted_packages:
        url = changelogs.get(package.name)
        if url is not None:
            print('## %s %s -> %s\n\n- %s\n' % (package.name, package.current, package.latest, url))

Python 3系を前提としていたが、先頭に

from __future__ import print_function

だけで2系も大丈夫そうだと感じた。