Prevent library from publishing if peerDependencies are missing

Question

I've created this NX workspace with some libraries which are published to NPM and github.

The following state of the repository causes the following error on installation

npm i @mintplayer/ng-json-ld
npm ERR! code ERESOLVE
npm ERR! ERESOLVE unable to resolve dependency tree
npm ERR!
npm ERR! While resolving: [email protected]
npm ERR! Found: @angular/[email protected]
npm ERR! node_modules/@angular/common
npm ERR!   @angular/common@"~16.2.0" from the root project
npm ERR!   peer @angular/common@"^16.0.0" from @mintplayer/[email protected]
npm ERR!   node_modules/@mintplayer/ng-json-ld
npm ERR!     @mintplayer/ng-json-ld@"*" from the root project
npm ERR!   1 more (@angular/platform-browser)
npm ERR!
npm ERR! Could not resolve dependency:
npm ERR! peer @angular/common@"16.2.1" from @angular/[email protected]
npm ERR! node_modules/@angular/router
npm ERR!   peer @angular/router@"16.2.1" from @mintplayer/[email protected]
npm ERR!   node_modules/@mintplayer/ng-json-ld
npm ERR!     @mintplayer/ng-json-ld@"*" from the root project
npm ERR!
npm ERR! Fix the upstream dependency conflict, or retry
npm ERR! this command with --force or --legacy-peer-deps
npm ERR! to accept an incorrect (and potentially broken) dependency resolution.
npm ERR!
npm ERR!
npm ERR! For a full report see:
npm ERR! C:\Users\User\AppData\Local\npm-cache\_logs\2023-08-26T17_45_08_268Z-eresolve-report.txt

npm ERR! A complete log of this run can be found in:
npm ERR!     C:\Users\User\AppData\Local\npm-cache\_logs\2023-08-26T17_45_08_268Z-debug-0.log

package.json

"peerDependencies": {
  "@angular/common": "^16.0.0",
  "@angular/core": "^16.0.0",
  "@angular/platform-browser": "^16.0.0",
  "rxjs": "^7.8.0"
},

This turns out to be the culprit.

I added the @angular/router as a peerDependency, and now I can install the package without problems

"peerDependencies": {
  "@angular/common": "^16.0.0",
  "@angular/core": "^16.0.0",
  "@angular/router": "^16.0.0", // <-- explicitly added this
  "@angular/platform-browser": "^16.0.0",
  "rxjs": "^7.8.0"
}

@angular/router isn't used anywhere in the code. However somewhere in a specfile I need to use it. And if I don't range the version in the packagefile (^ x.x.x) I get the above error, even though I don't use the package in code, only in unit-tests.

These problems have been biting me several times. Is there a way I can prevent these imports in my libraries if the corresponding package.json doesn't yet contain the dependency?

Similar discussions:

• imports in .spec files can trigger a circular dependency error on build

I'm getting the impression I have to use a feature called enforce-module-boundaries, but I don't know yet how.