Why NX Eslint enforceBuildableLibDependency rule exists

So NX has some of its own eslint rules nx eslint rules docs, what is not immedaitly clear is one of those rules 'enforceBuildableLibDependency'. Why you have this implication/restriction for buildable libraries, why NX want to restrict import of 3th party libs inside buildable libs, they can't do it or they just want to restrict it what is the problem for buildable lib to import 3th party libs? Can someone explain why this restriction exists ?

PS If this "enforceBuildableLibDependency": false, rule is enabled in .eslintrc.base.json in your NX monorepo you will get this kind of error when your library is doing imports from 'node_modules'. Yes you can disable the esrule but the question remains why we have this limitation for nx buildable libraries in the first place.

ESLint: Buildable libraries cannot import or export from non-buildable libraries(@nx/enforce-module-boundaries

PS I am using vite within NX as as build/bundle tool and I don't see why this limitation exists.

Solution

I've recently stumbled across this issue and it was a design decision made by the Nx team

https://github.com/nrwl/nx/issues/4829

The following comment is from February 2020 https://github.com/nrwl/nx/issues/1765#issuecomment-589074590

I'm going to close this issue since we will not be supporting imports of non-buildable libraries from buildable ones. Instead, dependencies should be made buildable as well. This constraint makes sense if you think about shared libraries between two buildable parents.

parent-1       parent-2

      \          /

      shared-child

In this case if both parent-1 and parent-2 are buildable, but shared-child is not, then you will end up with the child being bundled into both libraries. What you want in most cases if to publish shared-child as a separate package, and specify it in dependencies of both parent-1 and parent-2.

We have a lint rule to help with this:

"@nrwl/nx/enforce-module-boundaries": [
  "error",
  {
    "enforceBuildableLibDependency": true,
    "allow": [],
    "depConstraints": [
      { "sourceTag": "*", "onlyDependOnLibsWithTags": ["*"] }
    ]
  }
]

And we'll be releasing a feature in the next version to make buildable libraries easier to work with. For example, if you run nx run-many --target=build --projects=parent-1,parent-2 then it will make sure shared-child is built first before attempting the build.