eslint-json

2.0.0 verified Sat Apr 25 auth: no javascript

JSON reporter for ESLint that outputs lint results as a JSON array. Version 2.0.0, stable, low maintenance. Key differentiator: simplifies piping ESLint output to other tools (e.g., CI, custom scripts) by using standard JSON format. No breaking changes since initial release. Commonly used in build pipelines. Lightweight with zero dependencies.

Common errors

error Error: Cannot find module 'eslint-json' ↓

cause Module not installed or path incorrect.

fix

npm install --save-dev eslint-json and use full path: eslint --format=./node_modules/eslint-json file.js

error TypeError: formatter is not a function ↓

cause Using wrong require pattern (e.g., import from ESM).

fix

Use require('eslint-json') and call as function: formatter(results, config);

error TypeError: results is not iterable ↓

cause Passed entire report object instead of results array.

fix

Use report.results (the array) as first argument.

Warnings

gotcha Must pass results array as first argument, not the full report object. ↓

fix Use report.results (array) instead of report (object).

gotcha The formatter output is a string, not a JavaScript object. Must JSON.parse before using as object. ↓

fix const output = JSON.parse(formatter(results, config));

gotcha When using ESLint CLI, the format path must be exactly 'node_modules/eslint-json' or full path; relative path may fail if cwd is not project root. ↓

fix Use absolute path or 'node_modules/eslint-json'.

Install

npm install eslint-json

yarn add eslint-json

pnpm add eslint-json

Imports

default

wrong

import eslintJson from 'eslint-json';

correct

const eslintJson = require('eslint-json');

Package is CJS only; no default export for ESM. Use require().

results

wrong

const results = require('eslint-json').format(results, config);

correct

const results = require('eslint-json')(results, config);

Direct call returns formatted JSON string; no .format method.

ESLint formatter

wrong

eslint --format=json file.js

correct

eslint --format=node_modules/eslint-json file.js

Must specify full path to module, not just 'json'.

Quickstart

Demonstrates how to programmatically use eslint-json to format ESLint results as JSON.

const eslint = require('eslint');
const formatter = require('eslint-json');
const cli = new eslint.CLIEngine({});
const report = cli.executeOnFiles(['index.js']);
const jsonOutput = formatter(report.results, report.config);
console.log(jsonOutput);