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Package detail

keep-func-props

ehmicky617.7kMIT7.1.1TypeScript support: included

Wrap a function without changing its name and other properties

function, functional, functional-programming, wrapper, name, length, properties, functor, mimic, call, typescript

readme

<picture> <source media="(prefers-color-scheme: dark)" srcset="https://raw.githubusercontent.com/ehmicky/design/main/keep-func-props/keep-func-props_dark.svg"/> keep-func-props logo </picture>

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Wrap a function without changing its name and other properties.

Function wrappers return a new function which means the original function's name and other properties are usually lost. This module enhances them to keep those properties instead.

The new function will also print the original function's body when stringified.

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.

Example

import keepFuncProps from 'keep-func-props'
// Any function wrapper works
import memoize from 'lodash/memoize.js'

const betterMemoize = keepFuncProps(memoize)

const anyFunction = () => true

// Function `name` and other properties are kept
console.log(anyFunction) // `[Function: anyFunction]`
console.log(memoize(anyFunction)) // `[Function: memoized]`
console.log(betterMemoize(anyFunction)) // `[Function: anyFunction]`

// Function body is kept when stringified
console.log(String(anyFunction))
// () => true
console.log(String(memoize(anyFunction)))
// function() {
//   var args = arguments,
//   key = resolver ? resolver.apply(this, args) : args[0],
//   cache = memoized.cache;
//   ...
// }
console.log(String(betterMemoize(anyFunction)))
// /* Wrapped with memoized() */
// () => true

Install

npm install keep-func-props

This package works in both Node.js >=18.18.0 and browsers.

This is an ES module. It must be loaded using an import or import() statement, not require(). If TypeScript is used, it must be configured to output ES modules, not CommonJS.

Usage

import keepFuncProps from 'keep-func-props'

// Any function wrapper works
const wrapper =
  (anyFunction) =>
  (...args) =>
    anyFunction(...args)

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

keepFuncProps(wrapper)

wrapper: (anyFunction, [...args]) => newFunction\ Returns: new wrapper

A function wrapper is passed as argument. A copy of it is returned.

See also

  • mimic-function: same but for functions that do not wrap other functions.

Support

For any question, don't hesitate to submit an issue on GitHub.

Everyone is welcome regardless of personal background. We enforce a Code of conduct in order to promote a positive and inclusive environment.

Contributing

This project was made with ❤️. The simplest way to give back is by starring and sharing it online.

If the documentation is unclear or has a typo, please click on the page's Edit button (pencil icon) and suggest a correction.

If you would like to help us fix a bug or add a new feature, please check our guidelines. Pull requests are welcome!

changelog

7.1.1

Documentation

  • Update README.md

7.1.0

Dependencies

  • Upgrade mimic-function

7.0.0

Breaking changes

  • Minimal supported Node.js version is now 18.18.0

6.0.0

Breaking changes

  • Minimal supported Node.js version is now 16.17.0

5.5.0

Features

  • Improve tree-shaking support

5.4.0

Features

  • Add browser support

5.3.1

Bug fixes

  • Fix package.json

5.3.0

  • Switch to MIT license

5.2.0

Features

  • Reduce npm package size

5.1.0

Features

  • Add TypeScript types

5.0.0

Breaking changes

  • Minimal supported Node.js version is now 14.18.0

4.0.1

Bug fixes

  • Fix main field in package.json

4.0.0

Breaking changes

  • Minimal supported Node.js version is now 12.20.0
  • This package is now an ES module. It can only be loaded with an import or import() statement, not require(). See this post for more information.

3.0.1

Bug fixes

  • Fixes support in React Native

3.0.0

Breaking changes

  • Minimal supported Node.js version is now 10.17.0