eslint-formatting-reporter

0.0.0 verified Sat Apr 25 auth: no javascript

A utility library for ESLint plugins that report formatting differences between original and formatted code. Version 0.0.0, actively maintained by Anthony Fu. Extracted from eslint-plugin-prettier, it provides `reportDifferences` function and `messages` object to simplify creating custom formatting rules. Ships TypeScript types, peer dependency on ESLint >=8.40.0. Lightweight alternative to directly using prettier-linter-helpers.

Common errors

error Cannot find module 'eslint-formatting-reporter' ↓

cause Package not installed or incorrect import path.

fix

npm install eslint-formatting-reporter

error ERR_REQUIRE_ESM ↓

cause Using require() for an ESM-only package.

fix

Change to import { reportDifferences } from 'eslint-formatting-reporter'

Warnings

gotcha reportDifferences requires context.source.text. In older ESLint versions, use context.getSourceCode().getText(). ↓

fix Use context.source.text for ESLint 8.40+; for older versions, upgrade or pass source code manually.

gotcha Package is ESM-only. Using require() will fail with ERR_REQUIRE_ESM. ↓

fix Use import syntax or dynamic import().

Install

npm install eslint-formatting-reporter

yarn add eslint-formatting-reporter

pnpm add eslint-formatting-reporter

Imports

reportDifferences

wrong

const { reportDifferences } = require('eslint-formatting-reporter')

correct

import { reportDifferences } from 'eslint-formatting-reporter'

ESM-only; CommonJS require will not work this package is ESM.

messages

import { messages } from 'eslint-formatting-reporter'

Used for ESLint rule meta.messages.

Rule

wrong

import { Rule } from 'eslint-formatting-reporter'

correct

import type { Rule } from 'eslint'

Rule type is from eslint, not this package.

Quickstart

Creates a custom ESLint rule that reports formatting differences using reportDifferences.

import { messages, reportDifferences } from 'eslint-formatting-reporter';
import type { Rule } from 'eslint';

export default <Rule.RuleModule>{
  meta: {
    type: 'layout',
    fixable: 'whitespace',
    messages
  },
  create(context) {
    return {
      Program() {
        const source = context.source.text;
        const formatted = source.replace(/\s+$/, ''); // example formatter
        reportDifferences(context, source, formatted);
      }
    };
  }
};