https://twitter.com/yuta0381/status/1192440258756935681

refactor-nested-if.js

function nativeApLoginStart() {
  const [d, a] = installVersionCheck(false)

  if (d && a) return

  const dialogMap = {
    Win: {
      IE: '#ieInstallDialog',
      Edge: '#edgeInstallDialog',
      Chrome: '#chromeInstallDialog',
      Firefox: '#firefoxInstallDialog',
    },
    Mac: {
      Safari: '#safariInstallDialog',
      Chrome: '#chromeInstallDialog',
      Firefox: '#firefoxInstallDialog',
    }
  }
  
  const f = $('#browserType').val()
  const e = $('#osType').val()

  const dialog = dialogMap[e][f]
  $(dialog).dialog('open')
}