[PR WELCOME] Set language level for library sources (es5, es6, es7, dom, webworker, ...)

Type of Issue

• Bug Report
• Feature Request

Description

I have made an application using a custom component library that I have implemented, and now i wanted to use ng-packagr to externalize my custom component library. The application was created by angular-cli, and i have followed the tutorial of Nikolas LeBlanc and the structure shown in the ng-packaged project.

For some reasons i have used in development es7 features like includes on arrays and padStart on strings. With the angular-cli builds including polyfills of core-js everything was working fine but the ng-packagr build gave me errors like this

Property 'includes' does not exist on type 'any[]'.

I have tried to include them as externals and import them in the components that required the functions but still have theses errors.

So, how can i add polyfills functions on the build ?

Version Information

ng-packagr: v1.3.0
node: v7.10.0
@angular: v4.1.3
rxjs: v5.4.2
zone.js: v0.8.14
core-js: v2.4.1

[DavidParks8]

Why duplicate the lib config in ng-package.json and tsconfig.json? It should be possible to search for and read the developer’s tsconfig.json dynamically to determine what libs should be included. This could be accompanied by a field to specify a custom tsconfig file such as:

{
  "tsconfig": "./../tsconfig.app.json"
}

It would also be nice to dynamically search .angular-cli.json for the tsconfig.

[fr0]

What is the workaround for this? If there is no workaround, I can’t use ng-packagr until it is implemented.