eslint-plugin-promise

Enforce best practices for JavaScript promises.

• Installation
• Usage
• Rules
• Maintainers
• License

Installation

You'll first need to install ESLint:

$ npm install eslint --save-dev

Next, install eslint-plugin-promise:

$ npm install eslint-plugin-promise --save-dev

Note: If you installed ESLint globally (using the -g flag) then you must also install eslint-plugin-promise globally.

Usage

Add promise to the plugins section of your .eslintrc.json configuration file. You can omit the eslint-plugin- prefix:

{
  "plugins": ["promise"]
}

Then configure the rules you want to use under the rules section.

{
  "rules": {
    "promise/always-return": "error",
    "promise/no-return-wrap": "error",
    "promise/param-names": "error",
    "promise/catch-or-return": "error",
    "promise/no-native": "off",
    "promise/no-nesting": "warn",
    "promise/no-promise-in-callback": "warn",
    "promise/no-callback-in-promise": "warn",
    "promise/avoid-new": "warn",
    "promise/no-new-statics": "error",
    "promise/no-return-in-finally": "warn",
    "promise/valid-params": "warn"
  }
}

or start with the recommended rule set:

{
  "extends": ["plugin:promise/recommended"]
}

Rules

rule	description	recommended	fixable
catch-or-return	Enforces the use of catch() on un-returned promises.	‼️
no-return-wrap	Avoid wrapping values in Promise.resolve or Promise.reject when not needed.	‼️
param-names	Enforce consistent param names and ordering when creating new promises.	‼️
always-return	Return inside each then() to create readable and reusable Promise chains.	‼️
no-native	In an ES5 environment, make sure to create a Promise constructor before using.
no-nesting	Avoid nested then() or catch() statements	⚠️
no-promise-in-callback	Avoid using promises inside of callbacks	⚠️
no-callback-in-promise	Avoid calling cb() inside of a then() (use nodeify instead)	⚠️
avoid-new	Avoid creating new promises outside of utility libs (use pify instead)
no-new-statics	Avoid calling new on a Promise static method	‼️	🔧
no-return-in-finally	Disallow return statements in finally()	⚠️
valid-params	Ensures the proper number of arguments are passed to Promise functions	⚠️
prefer-await-to-then	Prefer await to then()/catch()/finally() for reading Promise values	7️⃣
prefer-await-to-callbacks	Prefer async/await to the callback pattern	7️⃣

Key

icon	description
‼️	Reports as error in recommended configuration
⚠️	Reports as warning in recommended configuration
7️⃣	ES2017 Async Await rules
🔧	Rule is fixable with eslint --fix

Maintainers

• Jamund Ferguson - @xjamundx
• Macklin Underdown - @macklinu
• Aadit M Shah - @aaditmshah

License

• (c) MMXV jden mailto:jason@denizac.org - ISC license.
• (c) 2016 Jamund Ferguson mailto:jamund@gmail.com - ISC license.