is-callback-function

is-callback-function

Returns true if function is a callback. Checks its name is one of common-callback-names - callback, cb, cb_, callback_, next, done, they can be customized, these are default.

Install

npm i is-callback-function --save

Usage

For more use-cases see the tests

const isCallbackFunction = require('is-callback-function')

isCallbackFunction

Check if given fn is callback function or not. Notice that "async" functions are not is-callback-function, they are is-async-function - it may be consfusing, but they are different.

Params

• fn {Function}
• names {Array}
• returns {Boolean}

Example

var fs = require('fs')
var isCallback = require('is-callback-function')
var isAsync = require('is-async-function')

console.log(isCallback(fs.readFile)) // => false
console.log(isAsync(fs.readFile)) // => true

console.log(isCallback(function (foo, bar, cb) {})) // => false
console.log(isAsync(function (foo, bar, cb) {})) // => true

console.log(isCallback(function callback (foo, bar) {})) // => true
console.log(isAsync(function callback (foo, bar) {})) // => false

console.log(isCallback(function named (foo, cb) {})) // => false
console.log(isAsync(function named (foo, cb) {})) // => true

console.log(isCallback(function named (foo) {})) // => false
console.log(isAsync(function named (foo) {})) // => false

console.log(isCallback(function foo (bar) {}, ['baz', 'foo', 'qux'])) // => true
console.log(isAsync(function foo (bar, qux) {}, ['baz', 'qux', 'aaa'])) // => true
console.log(isAsync(function foo (bar, qux) {}, ['baz', 'aaa'])) // => false

Whaaat?!

Need clarification? Both signatures are equal.

• is-callback-function - checks the name of given function
• is-async-function - checks the arguments names of given function

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
• in-array: Return true if a value exists in an array. Faster than using… more | homepage
• is-async-function: Is function really asynchronous function? Trying to guess that based on check… 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.

Charlike Make Reagent

Changelog

1.0.1 - 2016-05-08

• Release v1.0.1 / npm@v1.0.1
• update badges
• update test for ensurance
• fix readme example, close #2