Error: Can't resolve all parameters for Storage: (?, ?).

I’m using @ionic/storage in a non-ionic Angular2 Project. I never noticed this error when using it with Ionic, but I have now seen it while starting 2 Angular2 Projects that make use of the lib.

Error: Can't resolve all parameters for Storage: (?, ?).

I see this runtime error when my app.module.ts is set up as follows:

...
import { Storage } from '@ionic/storage';
@NgModule({
  providers: [
    Storage,
    ...
  ],
  ...
})
export class AppModule{ }

If I use a custom provider with no special values like this:

...
import { Storage } from '@ionic/storage';
export function provideStorage() {
 return new Storage();
}
@NgModule({
  providers: [
        { provide: Storage, useFactory: provideStorage },
    ...
  ],
  ...
})
export class AppModule{ }

then everything works no problem. Is this to be expected? From reading the Documentation it doesn’t seem like this should be necessary (and isn’t in my separate Ionic App).

environment details:

angular-cli: 1.0.0-beta.25.5
node: 6.9.3
os: win32 x64
@angular/common: 2.4.5
@angular/compiler: 2.4.5
@angular/core: 2.4.5
@angular/forms: 2.4.5
@angular/http: 2.4.5
@angular/material: 2.0.0-beta.1
@angular/platform-browser: 2.4.5
@angular/platform-browser-dynamic: 2.4.5
@angular/router: 3.4.5
@angular/compiler-cli: 2.4.5
@ionic/storage: 1.1.7

[jgw96]

Hello all, this is now fixed in the new 2.0.0 release 🎉. Instructions here on how to update.

[rapropos]

I think the README should be modified somehow to indicate that simply listing Storage in the providers array is not guaranteed to work any more, and that the more elaborate useFactory approach documented under the “Configuring Storage (new in 1.1.7)” section is mandatory, even if it is as simple as:

export function provideStorage() { return new Storage(); }
{provide: Storage, useFactory: provideStorage},

I believe something in angular-compiler changed somewhere between 2.2 and 4.0.0-beta.5 (perhaps with respect to optional or default parameters), and this is going to start biting people in droves. I tried adding @Optional decorators, but it did not seem to help.

UPDATE

Potentially related to angular #13609?