conductor/src/arity.js

A modern & functional JavaScript utility library

const arity = (length, fn) => {
  /* eslint-disable no-unused-vars */
  switch (length) {
  case 0:
    return function() {
      return fn.apply(this, arguments)
    }
  case 1:
    return function(a) {
      return fn.apply(this, arguments)
    }
  case 2:
    return function(a, b) {
      return fn.apply(this, arguments)
    }
  case 3:
    return function(a, b, c) {
      return fn.apply(this, arguments)
    }
  case 4:
    return function(a, b, c, d) {
      return fn.apply(this, arguments)
    }
  case 5:
    return function(a, b, c, d, e) {
      return fn.apply(this, arguments)
    }
  case 6:
    return function(a, b, c, d, e, f) {
      return fn.apply(this, arguments)
    }
  case 7:
    return function(a, b, c, d, e, f, g) {
      return fn.apply(this, arguments)
    }
  case 8:
    return function(a, b, c, d, e, f, g, h) {
      return fn.apply(this, arguments)
    }
  case 9:
    return function(a, b, c, d, e, f, g, h, i) {
      return fn.apply(this, arguments)
    }
  case 10:
    return function(a, b, c, d, e, f, g, h, i, j) {
      return fn.apply(this, arguments)
    }
  default:
    throw new Error(
      'First argument to arity must be a non-negative integer no greater than ten'
    )
  }
}

module.exports = arity