Consistent dependencies across your monorepo with Syncpack

Syncpack is a CLI tool that helps maintain consistent dependency versions across all packages in your monorepo.

You can use it to automatically fix version mismatches and integrate it into your CI pipeline to detect issues.

Setup

First, install syncpack in your project at the root of the monorepo:

npm install syncpack --save-dev
# or
yarn add syncpack --dev
# or
pnpm add syncpack -DW

Then let's setup a basic configuration for Syncpack in a .syncpackrc file:

{
  "dependencyTypes": ["prod", "dev"],
  "sortPackages": true,
  "semverGroups": [
    {
      "label": "enforce versions to match",
      "range": "",
      "dependencyTypes": ["prod", "dev"],
      "dependencies": ["**"],
      "packages": ["**"]
    }
  ]
}

This will ensure that all production and development dependencies are the same across all packages.

Then run a simple check to see if you have any inconsistencies:

npx syncpack list-mismatches

To automatically fix version mismatches:

npx syncpack fix-mismatches

Finally, to fix the formatting of your package.json files, run:

npx syncpack format

CI (GitHub Actions and others)

Add the following step to your CI pipeline so that errors are automatically reported:

npx syncpack lint

Conclusion

For teams working with monorepos, syncpack is one of those small tools that delivers great benefits in terms of developer experience and help prevent some issues down the line.