Expand user agent strings from a CSV

package.json

{
  "dependencies": {
    "fast-csv": "^4.3.6",
    "ua-parser-js": "^1.0.2"
  }
}

ua.js

const csv = require("fast-csv");
const { UAParser } = require("ua-parser-js");

const toCamelCase = (str) =>
  str.toLowerCase().replace(/[^a-z]+(.)/gi, (_, char) => char.toUpperCase());

const formatBrowserName = (browserName, browserMajor) => {
  if (!browserName) {
    return undefined;
  }

  if (browserMajor && browserName === "IE") {
    return `${browserName} ${browserMajor}`;
  }

  return browserName;
};

process.stdin
  .pipe(
    csv.parse({
      headers: (headers) => headers.map((h) => toCamelCase(h)),
    })
  )
  .transform((row, next) => {
    const { userAgent, ...otherColumns } = row;

    const parser = new UAParser(userAgent);
    const browser = parser.getBrowser();
    const os = parser.getOS();

    const niceBrowserName = formatBrowserName(browser.name, browser.major);
    const niceOsName =
      os.name && os.version ? `${os.name} ${os.version}` : os.name;

    return next(null, {
      userAgent,
      browser: niceBrowserName,
      browserName: browser.name,
      browserVersion: browser.version,
      browserMajor: browser.major,
      os: niceOsName,
      osName: os.name,
      osVersion: os.version,
      ...otherColumns,
    });
  })
  .pipe(csv.format({ headers: true }))
  .pipe(process.stdout)
  .on("end", () => process.exit());