Configure Linting for a Monorepo with Prettier and Import Validation

Problem/Feature Description

A JavaScript monorepo uses Prettier for code formatting and wants to add ESLint v9 with neostandard for code quality rules (not style rules — Prettier already handles formatting). The project also has strict requirements around import/export correctness and wants ESLint to enforce that no modules import from non-existent paths or use circular dependencies.

The repo has a .gitignore that already lists the directories that should be excluded from tooling (dist/, coverage/, node_modules/, etc.), and the team doesn't want to maintain a separate list of ESLint ignores. They also use semicolons consistently throughout the codebase (semistandard style).

Produce an eslint.config.js and an updated package.json with the correct dependencies and scripts. Do NOT run npm install.

Output Specification

• eslint.config.js — ESLint v9 flat config using neostandard with appropriate options for this setup
• Updated package.json — with all required devDependencies and npm lint scripts

Input Files

The following files are provided as inputs. Extract them before beginning.

=============== FILE: package.json =============== { "name": "monorepo-tools", "version": "1.0.0", "type": "module", "scripts": { "format": "prettier --write .", "build": "node scripts/build.js" }, "devDependencies": { "prettier": "^3.2.0" } }

=============== FILE: .gitignore =============== node_modules/ dist/ coverage/ .env *.log tmp/

=============== FILE: src/index.js =============== import { helper } from './helper.js'

export function run() { return helper('world'); }

=============== FILE: src/helper.js =============== export function helper(name) { return Hello, ${name}!; }