Enforce best practices for JavaScript promises
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Latest commit 61a373c Sep 6, 2018

README.md

eslint-plugin-promise

Enforce best practices for JavaScript promises.

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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() 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

License