Angular warns on CommonJS or AMD dependencies

[AlexElin]

When a class in Angular app uses types from the library, Angular prints the following warning while executing ng build.

Versions
Angular: v14+ (I've not checked on earlier ones).
type-comparator: 0.2.9

[lightness]

Let me dive into the problem. :)

[AlexElin]

I suppose the module property in tsconfig.json should be changed from commonjs to at least ES2015.

tsconfig.json

[lightness]

That's true.
But then other consumers cannot do require('type-comparator'). Just tested....
Even node-fetch made a major release to support ESM...

Not sure it's right direction... But may be someone help me to find a way to support both CJS and ESM 😄

[vasaeps3]

@AlexElin I hope this link will help you
https://angular.io/guide/build#configuring-commonjs-dependencies

for me it works

[AlexElin]

@vasaeps3 In effect it's just ignoring the warning (suppressing it).
In my opinion a correct solution would be providing ESM modules.

There're a several ways to do this:

1. Switch to ESM from CJS. It's a breaking change.
   However, the version of this library starts with 0.
   According to the semver docs, it's ok to change public API in this case.
2. Provide both ESM and CJS.