Confusing error "WARNING: No name was provided for external module 'xxx' in output.globals – guessing 'xxx'" for absolute imports

Type of Issue

[x] Bug Report
[x] Feature Request

Description

When you use absolute imports inside lib you will get an absolutely confusing warning “No name was provided for external module ‘xxx’”.

Desired Behaviour

1. Add supports for absolute imports (related to #916). IMO this is much much better because
   • angular supported it
   • in a big app ‘path/to/Component’ much more readable than ../../../../../../../../../../../../Component
   • mixed style is also confusing
2. Show smart warning eg “Absolute imports don’t support, please use relative.”

Version Information

ng-packagr:            10.1.2
@angular/compiler:     10.1.3
rollup:                2.28.2
tsickle:
typescript:            4.0.3

[flash-me]

@LastDragon-ru Path Mappings are supported by ng-packagr. In order to understand the underlying issue, some context is needed:

• By doing this, importing from these mapped paths will be treated as externals (like if you would import sth. from node_modules)
• This means btw, that these imports won’t be included in your angular library
• The term “name” form the warning here refers to UMD ID's. Beside ESM and FESM Formats, APF specifies also UMD bundles to be included.
• The UMD ID of a package will be used to assign a property for globalThis (window for browsers), where the name of the property will be the UMD ID and the value are all the public exports of your library (e.g. here: window['xxx'])
• Now when another library imports yours, then your UMD ID can be provided, so the another library knows how the property is called for globalThis
• The issue here is, that ng-packagr cannot know under which UMD ID the path mapped imports will be attached to. Said that, it will ‘guess’ a ‘name’ and thankfully warns the user about that.

Recap

• If you are going to publish your library, consumer will have to import also the path mapped stuff, which are not bundled in your library
• To define the UMD ID of your library, set the umdId property in your ng-packagr config.
• To provide UMD ID’s from other libraries, you need to set key/value pairs in a umdModuleIds object in your ng-packagr config., wheree key is the import identifier and the value the UMD ID of that library.
• If you are not going to use UMD bundles (default angular app does not), then you don’t need to bother with all this.

To get away from the warning, just provide the same identifier you have used in the path mappings in your ng-packagr config

Real world example project (which I already linked in my previous reply):

• The path mappings are defined here for a shared library, which is used by other libraries / apps
• The shared library itself defines an UMD ID here
• The other libraries are provided with the UMD ID of shared here

This is also the proof, that path mappings are supported correctly 😉

cheers flash ⚡

[flash-me]

@LastDragon-ru You may want to fix the typo 😄 in your tsconfig.json it is written with a hyphen. ,

but thats the wrong way.

Do this.

cheers flash ⚡