Angular2 build under angular-cli with directive and ng build --prod

Question

I have an angular-cli app,

npm -v 3.10.8
node -v v6.9.1
angular2 ^2.4.0
angular/cli 1.0.0-beta.32.3

when I add to package.json this

"angular2-auto-scroll": "1.0.12"

angular2-auto-scrol website

and in app.module.ts import it

import { Angular2AutoScroll } from "angular2-auto-scroll/lib/angular2-auto-scroll.directive";

and add it to declarations section ng build --prod fails with this error

ERROR in Unexpected value 'Angular2AutoScroll in C:/coding/workspace/myapp/myapp-web/node_modules/angular2-auto-scroll/lib/angular2-auto-scroll.directive.d.ts' declared by the module 'AppModule in C:/coding/workspace/myapp/myapp-web/app_code/app/app.module.ts'
ERROR in ./app_code/main.ts Module not found: Error: Can't resolve './$$_gendir/app/app.module.ngfactory' in 'C:\coding\workspace\myapp\myapp-web\app_code'
 @ ./app_code/main.ts 6:0-74
 @ multi ./app_code/main.ts

however when I build with just ng build without --prod then all build fine. Does anyone know what could be the reason? Or any other way I can import this npm package so it does not fail PROD build?

Answer 1

The issue is with AOT compilation. AOT happens by default when using --prod flag.

take a look at the source code for angular2-auto-scroll That project defines one TS file in the src/angular2-auto-scroll.directive.ts

If you look at the tsconfig.js file specifically "module": "commonjs" . you'll see that the module this directive transpiles to is commonjs If you look in your project under C:/coding/workspace/myapp/myapp-web/node_modules/angular2-auto-scroll/lib/ you'll see a TS type definition .d.ts , a .js and a .map file. the js file is a commonjs module.

AOT does not like commonjs modules, you can research that on your own, it needs either an es5 or es6 module.

All that said, here are some options to fix it

• Copy the directive TS file from the source github angular2-auto-scroll.directive.ts to your prject and remove the dependency.
• or you can make a pull request to the repo asking to change the "module": "commonjs" to "module": "es6" note: I opened an issue for it here
• or if you do not care for aot, (which is highly recommended btw), you can cancel it by running build command with --aot=false read here on build options

hope this helps.

Resources on AOT: https://angular.io/docs/ts/latest/cookbook/aot-compiler.html https://github.com/angular/angular-cli/issues/1732