language-level.md

Change Language Level

To use es2016 or es2017 features in your library you need to set the languageLevel option in your ng-packagr config file or lib option in tsconfig.

For a list of valid values check TypeScript's handbook.

Non-Angular CLI Users

You can change the TypeScript language level support in tsconfig by setting lib.languageLevel property in the ngPackage section: For example:

{
  "ngPackage": {
    "lib": {
      "languageLevel": ["dom", "es2017"]
    }
  }
}

Angular CLI Users

If you are an Angular CLI users can amend the language level by setting the lib property under compilerOptions in your tsconfig.lib.json.