npm-check-engines

Check that your dependencies support your supported engines.

npm install -g npm-check-engines

Wait, what?

You specify the supported engines in your package.json:

{
  "engines": {
    "node": ">= 4.0"
  }
}

If any of your dependencies do not support any version >= 4.0 (4.0, 4.1, 4.2, 5.0 and so on), this script will tell you. It works by fetching a list of Node releases and then iterating over all dependencies.