opinionated test for truthy

isTruthy.js

const isTruthy = (expression) => {
  if (typeOf expression === 'number') return true // 0 returns true
  if (Array.isArray(expression) && expression.length < 1) return false // empty array returns false
  if typeOf expression === 'Object' && Object.keys(expression).length < 1) return false // empty object returns false
  return !!expression
}