4.0.0

Upgrade to eslint v9 and update all dependencies

Flat Config

This major release requires a complete rewrite of your projects' ESLint config file as we moved to the new Flat Config format.

Start by reading ESLint's migration guide: https://eslint.org/docs/latest/use/configure/migration-guide

ESM-only

This release moves forward and assumes ESM-only projects, so if you're still using CommonJS, you'll need to update your project to use ESM first.

Peer-dependencies

Some peer dependencies have been changed:

• @typescript-eslint/eslint-plugin -> typescript-eslint
• eslint-plugin-import -> eslint-plugin-import-x
• eslint-plugin-node -> eslint-plugin-n
• @typescript-eslint/parser is now packaged into typescript-eslint
• The resolver has changed to eslint-import-resolver-typescript

Packages to remove:

eslint-plugin-import eslint-plugin-node @typescript-eslint/eslint-plugin @typescript-eslint/parser

Packages to add:

@eslint/js eslint-plugin-import-x eslint-plugin-n typescript-eslint eslint-import-resolver-typescript

Packages to update:

eslint eslint-plugin-jsx-a11y eslint-plugin-react-hooks eslint-plugin-react

Prettier

The prettier entry has been changed from .cjs to .js, as we are now using ESM-only.

-  "prettier": "@masterworks/eslint-config-masterworks/prettier",
+  "prettier": "@masterworks/eslint-config-masterworks/prettier/prettier.js",

TypeScript

The minimum compatible TypeScript version is now 5.7.3.

React PropTypes

Rules related to PropTypes have been removed, as they have been deprecated and removed by the React Core Team. You should ideally remove PropTypes from your project and use TypeScript instead.

Improved detection of deprecated APIs

Most presets have warnings for the usage of deprecated rules. With the different upgrades this detection has improved and you most probably will get new warnings.