Wrap a function without changing its name, length and other properties.

Function wrappers are commonly used in functional programming. They take a function as input and return it wrapped. Examples include memoizing or ensuring a function is only called once.

However those wrappers return a new function which means the original function's name, length and other properties are lost. This module enhances a function wrapper to keep those properties.

const keepFuncProps = require('keep-func-props')
const memoize = require('lodash/memoize')

const betterMemoize = keepFuncProps(memoize)

const anyFunction = function() {
  return true
}

// Function name is `memoized`
console.log(memoize(anyFunction))

// Function name is `anyFunction`
console.log(betterMemoize(anyFunction))

Installation

npm install keep-func-props

Usage

const keepFuncProps = require('keep-func-props')

const functionWrapper = function(func) {
  return (...args) => func(...args)
}

// `betterWrapper` is like `functionWrapper` but it keeps the function
// properties
const betterWrapper = keepFuncProps(functionWrapper)

The function wrapper must:

• take a function as first argument
• take additional arguments (e.g. an options object)
• return a new function

Each of those requirements is optional.

Related projects

If you want to modify a function that is not a function wrapper, check out mimic-fn.