@nimblestudio/biome-config

Shared Biome configuration for Nimble projects. Provides composable presets for formatting, linting, and import organization across different project types.

Installation

npm install -D @nimblestudio/biome-config @biomejs/biome

@biomejs/biome is a peer dependency (>=2.0.0) and must be installed alongside this package.

Usage

Create a biome.json in your project root and extend the config that matches your project:

Base (all projects)

{
  "$schema": "./node_modules/@biomejs/biome/configuration_schema.json",
  "extends": ["@nimblestudio/biome-config/root.biome.json"]
}

React

Extends the root config with React-specific linting rules and Tailwind CSS support:

{
  "$schema": "./node_modules/@biomejs/biome/configuration_schema.json",
  "extends": [
    "@nimblestudio/biome-config/root.biome.json",
    "@nimblestudio/biome-config/react.biome.json"
  ]
}

Next.js

Extends the root config with Next.js-specific linting rules:

{
  "$schema": "./node_modules/@biomejs/biome/configuration_schema.json",
  "extends": [
    "@nimblestudio/biome-config/root.biome.json",
    "@nimblestudio/biome-config/next.biome.json"
  ]
}

Note: The Next.js config sets the React linter domain to "none" because Next.js has its own set of rules. Do not combine next.biome.json with react.biome.json — use one or the other.

NestJS

Extends the root config with NestJS-specific settings (decorator support, relaxed import types):

{
  "$schema": "./node_modules/@biomejs/biome/configuration_schema.json",
  "extends": [
    "@nimblestudio/biome-config/root.biome.json",
    "@nimblestudio/biome-config/nest.biome.json"
  ]
}

Monorepo setup

Biome walks up the directory tree looking for configuration files. In a monorepo, this means you need to be deliberate about where configs live so that packages pick up the right settings.

How Biome resolves configuration

1. Biome starts from the file being checked and walks up directories looking for a biome.json.
2. When it finds one, it checks for "root": true (the default). If set, resolution stops there.
3. If "root": false, Biome merges that config with any parent config found further up the tree.

This means a monorepo root biome.json acts as the base, and each package can layer on its own overrides.

Recommended structure

monorepo/
├── biome.json              ← root config (root: true by default)
├── packages/
│   ├── web/
│   │   └── biome.json      ← extends root + adds React rules (root: false)
│   ├── api/
│   │   └── biome.json      ← extends root + adds NestJS rules (root: false)
│   └── shared/
│       └── (no biome.json) ← inherits root config automatically

Step 1: Root config

The monorepo root biome.json should extend the base config and serve as the default for all packages:

{
  "$schema": "./node_modules/@biomejs/biome/configuration_schema.json",
  "extends": ["@nimblestudio/biome-config/root.biome.json"]
}

Since "root" defaults to true, Biome will stop here for any package that doesn't have its own biome.json.

Step 2: Package-level configs

Packages that need framework-specific rules should add their own biome.json with "root": false. This tells Biome to merge the package config with the root config found further up the tree:

{
  "$schema": "../../node_modules/@biomejs/biome/configuration_schema.json",
  "extends": ["@nimblestudio/biome-config/react.biome.json"],
  "root": false
}

Key details:

• "root": false is required — without it, Biome stops at this file and won't inherit the root config's formatter and base linter settings.
• $schema path — In a monorepo with hoisted dependencies, point the schema to the root node_modules using a relative path (e.g. ../../node_modules/...).
• Only extend the framework config — The root biome.json already extends root.biome.json, so the package config only needs to add the framework-specific layer (e.g. react.biome.json). Biome merges them automatically.

Packages that only need the base config

If a package doesn't need framework-specific rules, you have two options:

1. No biome.json at all — Biome walks up and finds the root config. Simplest approach.
2. Explicit biome.json with root: false — Useful if you want to add package-specific overrides later:

{
  "$schema": "../../node_modules/@biomejs/biome/configuration_schema.json",
  "extends": ["@nimblestudio/biome-config/root.biome.json"],
  "root": false
}

Overriding rules

You can override any setting from the shared configs in your project's biome.json. Rules defined later in the file take precedence over extended configs:

{
  "$schema": "./node_modules/@biomejs/biome/configuration_schema.json",
  "extends": ["@nimblestudio/biome-config/root.biome.json"],
  "linter": {
    "rules": {
      "suspicious": {
        "noConsole": "error"
      }
    }
  },
  "formatter": {
    "lineWidth": 80
  }
}

Available configs

| Config | Description | | ------------------- | -------------------------------------------------------- | | root.biome.json | Base formatter and linter settings (2-space indent, single quotes, import organization) | | react.biome.json | React recommended linting, relaxed a11y rules, Tailwind CSS parsing | | next.biome.json | Next.js recommended linting (sets React domain to none) | | nest.biome.json | Unsafe parameter decorators, useImportType off |

Config composition

The configs are designed to be layered on top of root.biome.json:

• root — Always required. Provides formatter settings, base linter rules, and import organization.
• react — Adds React linting and Tailwind CSS support. Use for React apps (Vite, CRA, etc.).
• next — Adds Next.js linting. Do not combine with react — Next.js replaces the React domain with its own rules.
• nest — Adds NestJS support (decorators, relaxed import types). Use for NestJS backends.

What's included

Formatter

• 2-space indentation
• 120 character line width
• Single quotes (single quotes in JSX too)
• Semicolons as needed
• Trailing commas everywhere
• Arrow function parentheses always

Linter

• Unused imports auto-fixed (warn level)
• Console logging restricted to assert, error, info, warn, time, timeLog, timeEnd
• SVG title rule disabled
• Literal keys rule disabled

Import organization

Imports are automatically organized into three groups separated by blank lines:

1. URL and Node.js built-in imports (node:, https://)
2. Package imports (react, @nestjs/core, etc.)
3. Alias and relative path imports (@/, ./, ../)

License

MIT