extractor.js

const { existsSync, mkdirSync, readFileSync, writeFileSync } = require('fs');
const { i18nextToPot } = require('i18next-conv');
const recursive = require("recursive-readdir");

const argv = require('minimist')(process.argv.slice(2));
const filename = argv['o'] || 'en.pot';

const JS_FUNCTION_REGEX = new RegExp("i18next.t\\('(.*)'\\)", 'g');

const getFileExtension = (filename) => {
    return filename.split('.').pop();
};

// save file to disk
const save = (target) => {
    return result => {
        writeFileSync(target, result);
    };
};

let translations = {};
const addKeysFromFileContent = (fileContent, functionRegex) => {
    let matches;
    while (( matches = functionRegex.exec(fileContent))) {
        if (matches[1]) {
            translations[matches[1]] = '';
        }
    }
};

recursive('src', function (err, files) {
    for (let file of files) {
        const fileExtension = getFileExtension(file);
        if (fileExtension === 'js') {
            addKeysFromFileContent(readFileSync(file, 'utf-8'), JS_FUNCTION_REGEX);
        }
    }

    if (!existsSync('i18n/')){
        mkdirSync('i18n/');
    }

    i18nextToPot('en', JSON.stringify(translations)).then(save('i18n/' + filename));
});