get browser name by user agent

getBrowserName.ts

export type BrowserName = 'edge' | 'chrome' | 'firefox' | 'safari' | 'opera' | 'ie';
export type BrowserCheck = (userAgent: UserAgent) => boolean;
export type UserAgent = string;

const BrowserCheckMap: Record<BrowserName, BrowserCheck> = Object.freeze({
  edge: agent => /Edg/.test(agent),
  chrome: agent => /Chrome/.test(agent),
  firefox: agent => /Firefox/.test(agent),
  safari: agent => /Safari/i.test(agent) && !/Chrome/i.test(agent),
  opera: agent => /Opera/.test(agent),
  ie: agent => /Trident|MSIE/.test(agent),
});

export function getBrowserName(userAgent: UserAgent): BrowserName | 'unknown' {
  const browser = Object.keys(BrowserCheckMap).find(
    (name: BrowserName) => BrowserCheckMap[name](userAgent)
  ) as BrowserName;

  if (browser) return browser;
  return 'unknown';
}