https://github.com/thejohnfreeman/callable-object

Trying to add function call operators to JavaScript objects.
https://github.com/thejohnfreeman/callable-object

Last synced: 21 days ago
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Trying to add function call operators to JavaScript objects.

• Host: GitHub
• URL: https://github.com/thejohnfreeman/callable-object
• Owner: thejohnfreeman
• License: mit
• Created: 2019-02-03T15:58:18.000Z (almost 6 years ago)
• Default Branch: master
• Last Pushed: 2019-02-04T18:00:43.000Z (almost 6 years ago)
• Last Synced: 2024-10-26T00:38:11.693Z (2 months ago)
• Language: TypeScript
• Size: 9.77 KB
• Stars: 1
• Watchers: 3
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

        
# callable-object

Function call operators for JavaScript objects.

[![code style: Prettier](https://img.shields.io/badge/code_style-prettier-ff69b4.svg?style=flat)](https://github.com/prettier/prettier)

[![build status](https://travis-ci.org/thejohnfreeman/callable-object.svg?branch=master)](https://travis-ci.org/thejohnfreeman/callable-object)

## Motivation

The API can be cleaned up, but for now this is a proof-of-concept. Given an

object and a function, return a proxy for the object that can be called like

the function. Inspired by a

[TypeScript issue](https://github.com/Microsoft/TypeScript/issues/183).

## Related work

- [callable-object](https://www.npmjs.com/package/callable-object)

- [callable-instance](https://www.npmjs.com/package/callable-instance)

- [callable-instance2](https://www.npmjs.com/package/callable-instance2): This

  might just be a republished copy of `callable-instance`.

- [invokable](https://www.npmjs.com/package/invokable)

- [How to extend Function with ES6 classes?](https://stackoverflow.com/q/36871299/618906)

## Caveats

[A proxy is not callable unless its target is

callable.](https://stackoverflow.com/a/32360219/618906) To guarantee our

target is callable, we use a dummy function, which means we have to override

every proxy trap to redirect them to our real target object. We can use

[`Reflect`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Reflect)

to help.

If we use a dummy function declared as a function or function expression, then

it will have non-configurable properties `prototype` and `arguments` that [we

must include in our own

properties](https://stackoverflow.com/a/42876020/618906). If we use an arrow

function instead, it only has configurable properties `name` and `length`.

My implementation here works in JavaScript, but not in TypeScript. I don't

know why.

If you have a method that returns `this`, it will not return the proxy unless

you manage it yourself: store a reference to the proxy, return it instead of

`this`, and initialize it with the proxy after constructing both the object

and the proxy.