Enforce best practices for JavaScript promises.
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.
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",
"promise/no-multiple-resolved": "error"
}
}
or start with the recommended rule set:
-
eslint.config.js
:import pluginPromise from 'eslint-plugin-promise' export default [ // ... pluginPromise.configs['flat/recommended'], ]
-
.eslintrc.*
:{ "extends": ["plugin:promise/recommended"] }
💼 Configurations enabled in.
🚫 Configurations disabled in.
✅ Set in the flat/recommended
configuration.
✅ Set in the recommended
configuration.
🔧 Automatically fixable by the
--fix
CLI option.
Name | Description | 💼 | 🚫 | 🔧 | |
---|---|---|---|---|---|
always-return | Require returning inside each then() to create readable and reusable Promise chains. |
✅ | |||
avoid-new | Disallow creating new promises outside of utility libs (use util.promisify instead). |
✅ | |||
catch-or-return | Enforce the use of catch() on un-returned promises. |
✅ | |||
no-callback-in-promise | Disallow calling cb() inside of a then() (use util.callbackify instead). |
✅ | |||
no-multiple-resolved | Disallow creating new promises with paths that resolve multiple times. | ||||
no-native | Require creating a Promise constructor before using it in an ES5 environment. |
✅ | |||
no-nesting | Disallow nested then() or catch() statements. |
✅ | |||
no-new-statics | Disallow calling new on a Promise static method. |
✅ | 🔧 | ||
no-promise-in-callback | Disallow using promises inside of callbacks. | ✅ | |||
no-return-in-finally | Disallow return statements in finally() . |
✅ | |||
no-return-wrap | Disallow wrapping values in Promise.resolve or Promise.reject when not needed. |
✅ | |||
param-names | Enforce consistent param names and ordering when creating new promises. | ✅ | |||
prefer-await-to-callbacks | Prefer async /await to the callback pattern. |
||||
prefer-await-to-then | Prefer await to then() /catch() /finally() for reading Promise values. |
||||
spec-only | Disallow use of non-standard Promise static methods. | ||||
valid-params | Enforces the proper number of arguments are passed to Promise functions. | ✅ |
- Jamund Ferguson - @xjamundx
- Macklin Underdown - @macklinu
- Aadit M Shah - @aaditmshah
- (c) MMXV jden mailto:jason@denizac.org - ISC license.
- (c) 2016 Jamund Ferguson mailto:jamund@gmail.com - ISC license.