# Linting neostandard ESLint 9

> Use when ESLint flat config or neostandard needs setting up or migrating.

Configures ESLint v9 flat config and neostandard for JavaScript and TypeScript projects, including migrating from legacy `.eslintrc*` files or the `standard` package. Use when you need to set up or fix linting with `eslint.config.js` or `eslint.config.mjs`, troubleshoot lint errors, configure neostandard rules, migrate from `.eslintrc` to flat config, or integrate linting into CI pipelines and pre-commit hooks.

## Facts

- Type: Agent skill
- Discipline: Engineering
- Author: Matteo Collina (https://github.com/mcollina)
- Upstream: https://github.com/mcollina/skills/blob/main/skills/linting-neostandard-eslint9/SKILL.md
- Source file: https://raw.githubusercontent.com/mcollina/skills/main/skills/linting-neostandard-eslint9/SKILL.md (2673 bytes, sha256:acfe85c6b54057d48fde3b6e701272a4fd81e27f60b873486f26111405ac7ffe)
- Licence: MIT
- Upstream copy last changed: 2026-09-17
- Status: listed, not yet ruled on by the curator

## Use it

I want to use the Linting neostandard ESLint 9 skill by Matteo Collina.
This is what it does, in the author's own words: Configures ESLint v9 flat config and neostandard for JavaScript and TypeScript projects, including migrating from legacy `.eslintrc*` files or the `standard` package. Use when you need to set up or fix linting with `eslint.config.js` or `eslint.config.mjs`, troubleshoot lint errors, configure neostandard rules, migrate from `.eslintrc` to flat config, or integrate linting into CI pipelines and pre-commit hooks.
Download the whole folder at https://github.com/mcollina/skills/tree/main/skills/linting-neostandard-eslint9, SKILL.md and every file beside it, into your skills directory: ~/.claude/skills/linting-neostandard-eslint9/ for Claude Code, ~/.agents/skills/linting-neostandard-eslint9/ for Codex, ~/.cursor/skills/linting-neostandard-eslint9/ for Cursor. Get it from the author's repo, not from startupskills.dev.
Then tell me the path you installed it to and how to invoke it.

Nothing here is vendored: install from the author's repo, not from this site. A verbatim copy of the author's file follows for reading, under the licence reproduced after it; the current file is in the author's repo.

## Links

- Page: https://startupskills.dev/mcollina/linting-neostandard-eslint9
- Author: https://startupskills.dev/mcollina
- Index: https://startupskills.dev/llms.txt

## The file itself

---
name: linting-neostandard-eslint9
description: Configures ESLint v9 flat config and neostandard for JavaScript and TypeScript projects, including migrating from legacy `.eslintrc*` files or the `standard` package. Use when you need to set up or fix linting with `eslint.config.js` or `eslint.config.mjs`, troubleshoot lint errors, configure neostandard rules, migrate from `.eslintrc` to flat config, or integrate linting into CI pipelines and pre-commit hooks.
metadata:
  tags: linting, neostandard, eslint, eslint9, flat-config, javascript, typescript
---

## When to use

Use this skill when you need to:
- Set up linting in a JavaScript or TypeScript project
- Use `neostandard` as a Standard-like ESLint v9 flat-config baseline
- Configure `eslint@9` with the flat config system (`eslint.config.js`/`eslint.config.mjs`)
- Migrate from `standard` to `neostandard` or ESLint v9
- Migrate from legacy `.eslintrc*` configuration to ESLint v9
- Run linting consistently in CI and local development

## Quick start: basic neostandard setup

Install dependencies and create a minimal `eslint.config.js`:

```bash
npm install --save-dev eslint@9 neostandard
```

```js
// eslint.config.js
import neostandard from 'neostandard'

export default neostandard()
```

Verify the config works:

```bash
npx eslint .
```

## Common setup workflow (new project)

1. Install `eslint@9` and `neostandard` (see Quick start above)
2. Create `eslint.config.js` with `neostandard()` as the base
3. Add any project-specific rule overrides on top
4. Run `npx eslint .` to confirm no config errors
5. Add a lint script to `package.json`: `"lint": "eslint ."`
6. Integrate into CI with a non-fix run; use `--fix` only in local workflows

## How to use

Read individual rule files for implementation details and examples:

- [rules/neostandard.md](rules/neostandard.md) - Install, configure, and extend neostandard with ESLint
- [rules/eslint-v9-flat-config.md](rules/eslint-v9-flat-config.md) - Build ESLint v9 flat config for JS/TS projects
- [rules/migration-from-standard.md](rules/migration-from-standard.md) - Migrate from `standard` to `neostandard` or ESLint v9
- [rules/migration-from-legacy-eslint.md](rules/migration-from-legacy-eslint.md) - Migrate from `.eslintrc*` to flat config safely
- [rules/ci-and-editor-integration.md](rules/ci-and-editor-integration.md) - CI scripts, pre-commit, and editor setup

## Core principles

- Prefer reproducible linting with pinned major versions
- Keep config minimal and explicit
- Use flat config for ESLint v9 projects
- Treat lint failures as quality gates in CI
- Enable auto-fix for local workflows, but validate with non-fix CI runs

## Licence of the file above

The file above is https://raw.githubusercontent.com/mcollina/skills/main/skills/linting-neostandard-eslint9/SKILL.md, by Matteo Collina, reproduced without changes.
- Source: https://github.com/mcollina/skills/blob/main/skills/linting-neostandard-eslint9/SKILL.md
- Copyright: Copyright (c) 2026 Matteo Collina
- Licence: MIT, https://raw.githubusercontent.com/mcollina/skills/main/LICENSE

The repo's licence file, verbatim from https://raw.githubusercontent.com/mcollina/skills/main/LICENSE:

MIT License

Copyright (c) 2026 Matteo Collina

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.