Ionic-app-scripts - tree shaking - removing to much

Ionic Framework ionic-v3
#1

I have a fairly large TS library that heavily uses decorators. Now for some reason one of the decorators I use gets marked as unused by webpacks tree-shaking.

TypeScript file in question

import { Entity, Column, PrimaryGeneratedColumn } from 'typeorm';

@Entity() // this decorator is "unused"
export class User {
  @PrimaryGeneratedColumn() // this decorator is not unused
  user_id_internal: number;
  @Column()
  user_id: string;
  @Column()
  first_name: string;
  @Column()
  last_name: string;
}

which is turned into

var User = (function () {
    function User() {
    }
    return User;
}());
__decorate([
    Object(__WEBPACK_IMPORTED_MODULE_0_typeorm__["d" /* PrimaryGeneratedColumn */])(),
    __metadata("design:type", Number)
], User.prototype, "user_id_internal", void 0);
__decorate([
    Object(__WEBPACK_IMPORTED_MODULE_0_typeorm__["a" /* Column */])(),
    __metadata("design:type", String)
], User.prototype, "user_id", void 0);
__decorate([
    Object(__WEBPACK_IMPORTED_MODULE_0_typeorm__["a" /* Column */])(),
    __metadata("design:type", String)
], User.prototype, "first_name", void 0);
__decorate([
    Object(__WEBPACK_IMPORTED_MODULE_0_typeorm__["a" /* Column */])(),
    __metadata("design:type", String)
], User.prototype, "last_name", void 0);
User = __decorate([
    Object(__WEBPACK_IMPORTED_MODULE_0_typeorm__["b" /* Entity */])()
], User);

After ionic-app-scripts build this comment is added to the Entity decorator: /* unused harmony export Entity */ for the PrimaryGeneratedColumn this comment is added /* harmony export (immutable) */ __webpack_exports__["a"] = PrimaryGeneratedColumn;.

I added

"config": {
   "ionic_purge_decorators": false,
   "ionic_manual_treeshaking": false
}

to package.json but ionic_manual_treeshaking only disables the addional tree shaking.
I know, that this is not an issue of ionic directly and more of webpack. At least I think so. But maybe someone knows a way around this.

#2

Additional information: It seems like webpack or ionic has a problem with the name. When I change to a different decorator AbstractEntity everything is shaken correctly.
Is there a reason for it to not like Entity?

#3

Only thing that comes to mind is that it collides with an interface defined in the DOM.

#4

Thanks for the reply but it turned out, that deep in the library it was exported twice, a mistake the compiler seems to ignore but webpack does not like.

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