handle-arguments

Get separately non-callback arguments in .arguments and the last argument if it is-callback-function in .callback. It also works like sliced, but returns object with .arguments and .callback properties.

Install

npm i handle-arguments --save

Usage

For more use-cases see the tests

const handleArguments = require('handle-arguments')

handleArguments

Get separately non-callback arguments in .arguments, and the last function if it is-callback-function in .callback. Signature is like sliced, it works almost the same way, but returns object with .arguments and .callback properties.

Params

• argz {Array|Arguments}: Arguments object or array to eat.
• names {Array|Number}: If array directly passed to is-callback-function, otherwise to sliced.
• index {Number}: Passed directly to sliced if number.
• returns {Object}

Example

var handle = require('handle-arguments')
 
function fixture () {
  return handle(arguments)
}
 
function cb () {}
function noop () {}
 
console.log(fixture(1, 2, 3, 4).arguments) // => [1, 2, 3, 4]
console.log(fixture(1, 2, 3, 4).callback) // => false
 
console.log(fixture(1, 2, cb).arguments) // => [1, 2]
console.log(fixture(1, 2, cb).callback) // => [Function: cb]
 
console.log(fixture(1, 2, noop).arguments) // => [1, 2, noop]
console.log(fixture(1, 2, noop).callback) // => false
 
// treat functions named `noop` or `foo` as callback
function fn () {
  return handle(arguments, ['foo', 'noop'])
}
 
console.log(fn(1, 2, 3, noop).arguments) // => [1, 2, 3]
console.log(fn(1, 2, 3, noop).callback) // => [Function: noop]

Instead of commonly used and wrong pattern

It is part of "Optiomization Killers" and needed very much, so we need correct pattern to reuse.

function fixture () {
  var args = [].slice.call(arguments)
  var len = args.length
  var callback = args[len - 1]
 
  if (typeof callback === 'function') {
    args = args.slice(0, -1)
    callback.apply(null, [null].concat(args))
  }
  return args
}

Related

• arr-includes: Return true if any of passed values exists in array. Using in-array. | homepage
• common-callback-names: List of common callback names - callback, cb, callback_, next, done. | homepage
• function-arguments: Get arguments of a function, useful for and used in dependency injectors.… more | homepage
• get-fn-name: Get function name with strictness and correctness in mind. Also works for… more | homepage
• is-async-function: Is function really asynchronous function? Trying to guess that based on check… more | homepage
• is-callback-function: Returns true if function is a callback. Checks its name is one… more | homepage
• parse-function: Parse a function, arrow function or string to object with name, args,… more | homepage

Contributing

Pull requests and stars are always welcome. For bugs and feature requests, please create an issue.
But before doing anything, please read the CONTRIBUTING.md guidelines.

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