https://github.com/emphori/compose

A featherweight Promise composition and error handling library for JavaScript
https://github.com/emphori/compose

functional functional-programming javascript nodejs promise promise-chain typescript

Last synced: 9 days ago
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A featherweight Promise composition and error handling library for JavaScript

• Host: GitHub
• URL: https://github.com/emphori/compose
• Owner: emphori
• License: mit
• Created: 2022-06-23T10:55:16.000Z (over 2 years ago)
• Default Branch: main
• Last Pushed: 2023-11-28T23:18:59.000Z (about 1 year ago)
• Last Synced: 2024-12-14T05:12:37.663Z (21 days ago)
• Topics: functional, functional-programming, javascript, nodejs, promise, promise-chain, typescript
• Language: TypeScript
• Homepage:
• Size: 33.2 KB
• Stars: 1
• Watchers: 0
• Forks: 0
• Open Issues: 1
• Metadata Files:
  • Readme: README.md
  • License: LICENSE
  • Codeowners: .github/CODEOWNERS

Awesome Lists containing this project

README

        
# Compose

A drop-in extension for Promises, adding oodles of functional goodness through

composition and taking error handling to an entirely different level.

## Features

* **Lightweight and with almost no memory footprint,** the main package export

  comes in at well below 1KB, unminified, ungzipped.

* **A familiar Promise like interface** reduces the learning curve

  dramatically.

* **Robust types for TypeScript** are included in the package by default, with

  specific attention in areas such as scope narrowing, for heavily nested and

  complex compositions.

* **Interoperable with existing code by design,** to ensure that it's easy to

  introduce incrementally to your project without any pesky migrations.

## Installation

Compose is available from the NPM registry and as a GitHub Package. Whichever

source you prefer to use, the installation should remain the same.

```sh

# Using NPM

npm install @emphori/compose -S

# Or, using Yarn

yarn add @emphori/compose

```

## Examples

```ts

import { compose, reject } from '@emphori/compose'

import type { Promise } from '@emphori/promise'

// (userId: string) => Promise

const getUserOrg = compose(getUser).then(getOrgForUser)

function getUser(userId: string): Promise {

  return User.getById(userId).then((user) => {

    return user ?? reject(UserNotFound)

  })

}

function getOrgForUser(user: User): Promise {

  return Org.getById(user.orgId).then((org) => {

    return org ?? reject(OrgNotFound)

  })

}

```

## Contributing

If you're interested in contributing, or just want to learn more about Compose,

then head over to the [repository][repo] where you'll hopefully find all the

information you need.

[repo]: https://github.com/emphori/compose

## Licence

This project is released under the [MIT License][license]. Enjoy responsibly ❤️

[license]: https://github.com/emphori/compose/blob/HEAD/LICENSE