How to get your packages right (for example, upgrading from 3.0 to 4.0)


Asked here in slack:, the question is

Is there a way to simultaneously upgrade all npm libraries to a compatible version when moving to can4 from can3 ?

Unfortunately, there’s not an easy way of doing this. We’ve actually been talking about creating something to do this. For example:

So the process is currently a manual one. The place to start is to look at the dependencies of the package.json of the release you want to upgrade to. For example, here is 4.3.0:

Most likely, you don’t need all of those packages. You can probably start with the ones you need:

"can-component": "4.2.2",
"can-define": "2.4.0",
"can-debug": "1.3.0",
"can-route": "4.3.0",
"can-stache": "4.9.0",
"can-stache-route-helpers": "1.1.0",

Once that is done, I suggest adding ^ to get the latest 4.0 compatible versions of everything:

"can-component": "^4.2.2",
"can-define": "^2.4.0",
"can-debug": "^1.3.0",
"can-route": "^4.3.0",
"can-stache": "^4.9.0",
"can-stache-route-helpers": "^1.1.0",

IMPORTANT!!! package-lock.json is your enemy while doing this. Make sure to delete it (and keep deleting it) or add a .npmrc file with:



Once your app works again, it’s fine to bring back a package-lock.json. But anytime you change your packages, you should always:

  1. delete the package-lock
  2. delete node_modules
  3. update your package.json
  4. npm install