How to override your dependency’s dependencies (#tilPost)

npm released version 8.3 of their CLI client in December and it looks like an unspectacular release but includes a helpful new feature - "overrides".

The JavaScript ecosystem has been on fire since Node.js and npm appeared. There's always a package for everything, and people YOLO-publish whatever they please. It's a vibrant and enabling ecosystem feeling like the wild wild west. And of course, there are pros and cons to countless dependencies.

I love that I can "just install another package" but share the concerns about the increasing project complexity. Suppose your project relies on one dependency that depends on another dependency that again depends on another one just to add two numbers. In that case, countless things could go wrong. "npm overrides" give you more power over what's installed in your dependency tree.

Let's say one of your dependencies (1st level) relies on another dependency that includes outdated other dependencies (2nd level). There hasn't been an easy way to update dependencies down the tree other than forking and fixing your first-level dependency.

your-project
  |_ some-module @1.0.0
      |_ another-module-which-should-be-updated @1.0.0

You can now specify an overrides property in your package.json to override and enforce dependency versions in the tree.

{
  "overrides": {
    "bar@2.0.0": {
      "foo": "1.0.0"
    }
  }
}

The new feature comes in handy to

• patch a dependency with a known security issue
• replace an existing dependency with a fork
• make sure that the same package version is used everywhere.

It's such a welcome addition; thanks, npm! 🎉

Read more about it in the npm docs.