po2json.js

/* eslint-disable require-jsdoc */
import fs from 'fs';
import path from 'path';
import {po} from 'gettext-parser';

for (const arg of process.argv.slice(2)) {
  const outpath = './src/' + path.basename(arg) + '.ts';
  console.log(`${arg} => ${outpath}`);
  writePoFile(arg, outpath);
}

function assertHeader(name, value) {
  if (!value) {
    throw new Error(`Bad .po file. "${name}" header is missing`);
  }
}

function writePoFile(inpath, outpath) {
  const input = fs.readFileSync(inpath).toString().normalize();
  const poData = po.parse(input);
  const pluralHeader =
    poData.headers['plural-forms'] || poData.headers['Plural-Forms'];
  const language = poData.headers.language || poData.headers.Language;
  assertHeader('Plural-Forms', pluralHeader);
  assertHeader('Language', language);
  const dict = {};
  for (const msg of Object.values(poData.translations[''])) {
    const msgid = msg.msgid;
    const msgstr = msg.msgstr;
    if (msgid && msgid.length && msgstr && msgstr.length) {
      dict[msgid] = msgstr;
    }
  }
  const compactPo = {
    headers: {
      'plural-forms': pluralHeader,
      language: language,
    },
    contexts: {'': dict},
  };
  const outstream = fs.createWriteStream(outpath, {flags: 'w'});
  outstream.write('export default ');
  outstream.write(JSON.stringify(compactPo, null, 0));
  outstream.end();
}