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
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"] }
rule | description | recommended | fixable |
---|---|---|---|
catch-or-return | Enforces the use of catch() on un-returned promises. | :bangbang: | |
no-return-wrap | Avoid wrapping values in Promise.resolve or Promise.reject when not needed. | :bangbang: | |
param-names | Enforce consistent param names when creating new promises. | :bangbang: | :wrench: |
always-return | Return inside each then() to create readable and reusable Promise chains. | :bangbang: | |
no-native | In an ES5 environment, make sure to create a Promise constructor before using. | ||
no-nesting | Avoid nested then() or catch() statements | :warning: | |
no-promise-in-callback | Avoid using promises inside of callbacks | :warning: | |
no-callback-in-promise | Avoid calling cb() inside of a then() (use nodeify instead) | :warning: | |
avoid-new | Avoid creating new promises outside of utility libs (use pify instead) | ||
no-new-statics | Avoid calling new on a Promise static method | :bangbang: | |
no-return-in-finally | Disallow return statements in finally() | :warning: | |
valid-params | Ensures the proper number of arguments are passed to Promise functions | :warning: | |
prefer-await-to-then | Prefer await to then() for reading Promise values | :seven: | |
prefer-await-to-callbacks | Prefer async/await to the callback pattern | :seven: |
Key
icon | description |
---|---|
:bangbang: | Reports as error in recommended configuration |
:warning: | Reports as warning in recommended configuration |
:seven: | ES2017 Async Await rules |
:wrench: | Rule is fixable with eslint --fix |