tools/update-timezone.mjs

#!/usr/bin/env node
// Usage: tools/update-timezone.mjs
import { execSync, spawnSync } from 'node:child_process';
import { renameSync, readdirSync, rmSync } from 'node:fs';
import { exit } from 'node:process';

const fileNames = [
  'zoneinfo64.res',
  'windowsZones.res',
  'timezoneTypes.res',
  'metaZones.res',
];

const availableVersions = readdirSync('icu-data/tzdata/icunew', { withFileTypes: true })
.filter((dirent) => dirent.isDirectory())
.map((dirent) => dirent.name);

const currentVersion = process.versions.tz;
const latestVersion = availableVersions.sort().at(-1);

if (latestVersion === currentVersion) {
  console.log(`Terminating early, tz version is latest @ ${currentVersion}`);
  exit();
}

execSync('bzip2 -d deps/icu-small/source/data/in/icudt*.dat.bz2');
fileNames.forEach((file) => {
  renameSync(`icu-data/tzdata/icunew/${latestVersion}/44/le/${file}`, `deps/icu-small/source/data/in/${file}`);
  spawnSync(
    'icupkg', [
      '-a',
      file,
      'icudt*.dat',
    ], { cwd: 'deps/icu-small/source/data/in/' }
  );
  rmSync(`deps/icu-small/source/data/in/${file}`);
});
execSync('bzip2 -z deps/icu-small/source/data/in/icudt*.dat');
rmSync('icu-data', { recursive: true });