TS2322 issues in contactService.ts

[jmoerdyk]

I was trying to run this sample code today in the Aurelia project, and VS2017 15.8.1 and the command line build are giving issues with the API service in ./ClientApp/app/components/contact/contactServce.ts:

  ERROR in ./ClientApp/app/components/contacts/contactService.ts
  (16,9): error TS2322: Type 'Promise<void | Contact[]>' is not assignable to type 'Promise<Contact[]>'.

fail: Microsoft.AspNetCore.NodeServices[0]

    Type 'void | Contact[]' is not assignable to type 'Contact[]'.

fail: Microsoft.AspNetCore.NodeServices[0]

      Type 'void' is not assignable to type 'Contact[]'.

  ERROR in ./ClientApp/app/components/contacts/contactService.ts
  (23,9): error TS2322: Type 'Promise<void | Contact>' is not assignable to type 'Promise<Contact>'.

fail: Microsoft.AspNetCore.NodeServices[0]

    Type 'void | Contact' is not assignable to type 'Contact'.

fail: Microsoft.AspNetCore.NodeServices[0]

      Type 'void' is not assignable to type 'Contact'.

  ERROR in ./ClientApp/app/components/contacts/contactService.ts
  (30,9): error TS2322: Type 'Promise<void | Contact>' is not assignable to type 'Promise<Contact>'.

And I'm so new to TS that I don't know how to being fixing this.