Eslint plugin for JSON files
⚠️ Starting from major 2.0, rules need to be explicitely activated. See here the minimal config to add 🚨
$ npm install --save-dev eslint eslint-plugin-json# or$ yarn add --dev eslint eslint-plugin-json
Note: If you installed ESLint globally (using the
-g flag) then you must also install
json plugin ship with two recommended config you can use to easily activate it via the
It comes in two flavor: one strict (
recommended) and one allowing comments
You can run ESLint on individual JSON files or you can use the
--ext flag to add JSON files to the list.
eslint . --ext .json,.js eslint example.json
If you want more granular control over which rules, and wich severity you want
json to the list of plugins (You can omit the
Then pick your rules.
If you want them all, add the
json/json rule (or its alias
json/*). (this is what the
recommended config does)
The global rules (
json/json or its alias
json/*) activate all the rules.
Note it can be configured to ignore errors cause by comments.
To do so, add option
Here is the list of individual rules (with name in
kebab-case)in case you want granular error/warning level:
json/unknown(error that does not match previous ones)
How does eslint-plugin-json work?
Starting from version 1.3, this plugin relies on what VSCode uses for its implementation of JSON validation.
Originaly this plugin used to use JSHint, however due to heavy dependencies, it was replaced.
Why doesn't this plugin use
eslint itself or just
is more appropriate.
JSON.parse seems ideal, it is not designed to continue after the first error.
So if you have a missing trailing comma in the start of the file, the rest of the file
will go unlinted. A smarter parser that can self-correct after seeing errors is needed
which the VSCode implementation provides by leveraging the
Will this plugin provide more configuration?
It is now possible as you can see in the Configuration section
Additionally, support for autofixing common errors could be added in the feature.
eslint really the best tool to lint my JSON?
eslint plugin interface wasn't designed to lint a completely different language but
its interface is flexible enough to allow it. So this plugin is certainly unusual.
Ideally, your editor would natively supports linting JSON. If it doesn't though, then might as well use this plugin. Hacky linting is better than no linting :)