npm link with built code

Ever used npm link to work on local versions of a npm dependency, without having to publish it? If so, have you ever run into a problem with using npm link on a package that has 'built' code, for instance with webpack or rollup? I certainly have. Let say you have the following setup:

• Your package's Typescript source lives in /src
• You use the Typescript compiler to build your source to /dist
• You publish only the /dist folder

When you normally want to enable this package to be linkable, you run npm link for the package:

# some-npm-package
npm link

And then link to the package inside your project:

# some-project
npm link some-npm-package

However, this won't work if you build your source to a /dist folder. This is because from the project you are now linking to the root folder of the npm package. The solution to this is actually very simple. When running npm link in the package, instead of doing this from the root of the package, just go into the /dist folder, and run npm link from that folder:

$ pwd
/path/to/some-npm-package

$ cd dist
$ npm link
/path/to/nodejs/lib/node_modules/some-npm-package -> /path/to/some-npm-package/dist

$ cd /path/to/some-project
$ npm link some-npm-package
/path/to/some-project/node_modules/some-npm-package -> /path/to/nodejs/lib/node_modules/some-npm-package -> /path/to/some-npm-package/dist

This creates a symlink, not from the package root, but from the dist folder.

So, as said, a very simple solution. But as I've seen a lot of people struggle with this, this post might save someone some time 🙂.