flexifin/eslint-config

Code service level repo for sharing common sources through several FF projects.

Usage

Update ESlint to version 10:

npm install eslint@^10

Remove these packages from your project:

npm remove prettier \
  @typescript-eslint/parser \
  @typescript-eslint/eslint-plugin \
  eslint-plugin-prefer-arrow-functions \
  eslint-plugin-unused-imports \
  eslint-config-prettier \
  eslint-plugin-prettier \
  eslint-plugin-react \
  eslint-plugin-unicorn

Install package:

# npm
npm install -D @flexifin/eslint-config

# yarn
yarn add -D @flexifin/eslint-config

# pnpm
pnpm add -D @flexifin/eslint-config

# bun
bun install -D @flexifin/eslint-config

# deno
deno install --dev npm:@flexifin/eslint-config

Migration to FlexiFin code standard

Rename your project root ESLint config file to eslint.config.mjs and modify content to extend FlexiFin preset:

import flexiFin from '@flexifin/eslint-config';

export default flexiFin(
  {
    tsconfigRootDir: import.meta.dirname,
    strict: true, // optional (enables type-aware lint: recommendedTypeChecked + stylisticTypeChecked)
    nestSupport: true, // backend (NestJS, Swagger, Node plugin)
    nextSupport: true, // frontend (Next.js, React, Storybook, Playwright, i18next, TanStack Query, a11y)
    plugins: {
      // Every plugin defaults to true EXCEPT `jest` (off — Vitest is the default test runner).
      // Set false to opt out individually. Jest projects opt in:
      // jest: true, vitest: false,
      //
      // Note: TypeScript support (parser + @typescript-eslint plugin) is always on — it is
      // infrastructure, not a toggleable opinion. Override individual TS rules via userConfigs.
    },
    ignores: [
      // ignore paths
    ],
  },
  // Rule overrides go in subsequent userConfig arguments — they apply at the end of the
  // chain and override every preset rule. Add as many as you need; scope by `files` when needed.
  {
    rules: {
      'unicorn/no-array-reduce': 'off',
    },
  }
);

Real world example:

import flexiFin from '@flexifin/eslint-config';

export default flexiFin(
  {
    nextSupport: true,
    ignores: ['src/_api'],
  },
  {
    rules: {
      'unicorn/no-array-reduce': 'off',
    },
  },
  {
    files: ['**/*.spec.ts'],
    rules: {
      '@typescript-eslint/no-explicit-any': 'off',
    },
  }
);

Rename your project root Prettier config file to prettier.config.mjs and modify content to extend FlexiFin preset:

import flexiFin from '@flexifin/eslint-config/prettier';

export default flexiFin();

Silencing peer-dependency warnings

Some bundled plugins declare peers that don't apply to every project: @darraghor/eslint-plugin-nestjs-typed peer-deps on class-validator (relevant only for NestJS apps), eslint-plugin-jsx-a11y is still pinned to ESLint ≤9, and eslint-plugin-storybook requires Storybook 10.3.6+. Add the following to your monorepo root package.json to silence the noise:

{
  "pnpm": {
    "peerDependencyRules": {
      "allowedVersions": {
        "eslint-plugin-jsx-a11y>eslint": "10",
        "eslint-plugin-storybook>storybook": ">=10.3.5"
      },
      "ignoreMissing": ["class-validator"]
    }
  }
}

NestJS apps already use class-validator at runtime, so the ignoreMissing entry only matters for front-end / non-Nest packages — keep it monorepo-wide and the warning disappears regardless of project type.

To approve native build scripts (unrs-resolver etc.), run pnpm approve-builds once.

Contributors

🤖 auto updated with automd