README.md

yarn-including-multiple-versions-of-a-package

Definition of problem:

Let's say there are two packages named @package-a and @package-b. @package-b dependends on @package-a. @package-b's package.json includes:

"dependencies": {
  "@package-a": "1.0.0"
}

In @package-b's code, @package-a is required like so:

const packageA = require('@package-a');

I'm using both @package-a and @package-b in my code. I plan to use multiple versions of each, so I use aliasing to add them by different names.

"dependencies": {
  "@package-a-version-1.0.0": "npm:@[email protected],
  "@package-b-version-1.0.0": "npm:@[email protected],
}

In my script, I require @package-b-version-1.0.0 like so:

const packageB = require('@package-b-version-1.0.0');

And get error:

Error: Cannot find module @package-a

Looks like yarn did not install @package-a by its original un-aliased name, and @package-b's dependency is not met.

Expected behavior:

Script should resolve @package-a correctly.

Steps to reproduce the problem:

1. Clone repo
2. Run yarn install
3. Run yarn start