default value wrapper
if value is not defined or it matches with a pattern then it subtitutes with default value else passes as is
import Dflt from 'dflt'
const dflt = Dflt('oh fuck', 'oh god')
// ^ pattern ^ default
const bazquxval = fetchBazQux(/*...*/)
foobar(dflt(bazquxval)) // if bazquxval equals 'oh fuck' or not bazquxval: 'oh god' else bazquxval
// ...