Also warn if the same version is included multiple times

It’s possible for webpack to bundle multiple instances of a module even if the versions are the same. For example, here’s a partial webpack stats output I saw in my project just now. Notice how the WorkboxError module is included 6 times because the paths are different (even though the versions are the same):

[19] ./node_modules/workbox-precaching/node_modules/workbox-core/_private/WorkboxError.mjs 1.42 kB {0} [built]
[23] ./node_modules/workbox-strategies/node_modules/workbox-core/_private/WorkboxError.mjs 1.42 kB {0} [built]
[24] ./node_modules/workbox-broadcast-cache-update/node_modules/workbox-core/_private/WorkboxError.mjs 1.42 kB {0} [built]
[26] ./node_modules/workbox-cache-expiration/node_modules/workbox-core/_private/WorkboxError.mjs 1.42 kB {0} [built]
[28] ./node_modules/workbox-background-sync/node_modules/workbox-core/_private/WorkboxError.mjs 1.42 kB {0} [built]
[31] ./node_modules/workbox-routing/node_modules/workbox-core/_private/WorkboxError.mjs 1.42 kB {0} [built]

[philipwalton]

I can get you a full set of steps to reproduce the issue later, but off the top of my head here’s how you can do it:

npm install --save-dev workbox-precaching workbox-strategies workbox-broadcast workbox-cache workbox-background workbox-routing

That will install those packages as well as workbox-core @ version 3.0.1. Then you run the following:

npm install --save-dev workbox-core@3.0.0

That will force npm to put a version of workbox-core inside each of the above packages node_modules folder.

Then if you create a bundle the imports the 6 above packages, you’ll see workbox-core modules (e.g. WorkboxError.mjs included multiple times.

[masterkidan]

@caseycarroll42 : Consider the following issue package A -> package B 1.0.0 Package B 2.0.0 In this particular case, as there are breaking changes between the two versions of the packages (assuming they are properly semantic versioned), resolving to the root level package will not be desirable.

Additionally, my understanding is that the purpose of this particular plugin is to alert developers of potential duplications (both major and minor version changes) in their webpack configurations so that you can go ahead and add alias’s like your solution. Hence the reason for an option to check for duplications in the same version.