Monolinter

1.0.5 verified Fri May 01 auth: no javascript

Monolinter is a CLI tool for validating consistency across multiple package.json files in a monorepo (or single project). It checks for consistent package versions, duplicate package declarations, fuzzy version usage, and related package version matches. Current stable version is 1.0.5. Release cadence is low; last release was minor. Key differentiator: modular, extensible with custom validation modules, and designed for CI/CD integration. Alternatives like syncpack focus on version sync but monolinter also catches duplicates and related packages.

Common errors

error Cannot find module 'cosmiconfig' ↓

cause Missing peer dependency cosmiconfig

fix

Add cosmiconfig as a devDependency: yarn add -D cosmiconfig

error TypeError: Cannot read property 'match' of undefined ↓

cause A package.json file lacks a 'version' field (for exact version check)

fix

Ensure all included package.json files have a 'version' field, or exclude them from exact version validation.

error No configuration found. Create a .monolinterrc file. ↓

cause Monolinter cannot find any config file in the project root.

fix

Create a .monolinterrc file with at least an 'include' array.

Warnings

gotcha Glob patterns must match relative path from config file location ↓

fix Use relative paths from the directory containing .monolinterrc or the root where CLI is run.

gotcha Exact version validator rejects packages without version (e.g., file: or git dependencies) ↓

fix Exclude packages that use non-semver versions via exclude patterns in config.

breaking Version 1.0.4 removed peer dependencies on @babel/core and @babel/runtime ↓

fix No migration needed; those packages are no longer required.

deprecated ESLint-related checks were added in 1.0.3 but not documented; may change in future ↓

fix Check changelog for updates on related package validation.

Install

npm install monolinter

yarn add monolinter

pnpm add monolinter

Imports

monolinter CLI
wrong
```
npx monolinter
```
correct
```
yarn monolinter
```
Install as devDependency and run via yarn or npm scripts. npx may work but not guaranteed.
programmatic API
wrong
```
const monolinter = require('monolinter');
```
correct
```
import { Monolinter } from 'monolinter';
```
Package is not explicitly ESM, but default export is available. TypeScript types included.
config file
wrong
```
monolinter.config.ts
```
correct
```
.monolinterrc (JSON, YAML, or JS via cosmiconfig)
```
cosmiconfig supports .monolinterrc, .monolinterrc.json, .monolinterrc.yaml, monolinter.config.js, etc.

Quickstart

Shows basic usage with config file and CLI arguments, including example validation errors.

// Create .monolinterrc in project root:
{
  "include": ["package.json", "packages/*/package.json"]
}

// Add script to package.json:
{
  "scripts": {
    "lint:mono": "monolinter"
  }
}

// Run:
yarn lint:mono

// Or run directly:
yarn monolinter package.json 'packages/*/package.json'

// Sample output on failure:
// ✖ Found inconsistent versions for 'lodash': 4.17.0 vs 4.17.21
// ✖ Duplicate 'express' in dependencies and devDependencies of server/package.json
// ✖ App/package.json uses fuzzy version '^1.0.0' for 'debug'