Optional fields affecting keyof operator in generic class decorators

TypeScript Version: 3.2.2

Search Terms:
class decorator keyof typescript

Code

function View<T>(name: string, fields: (keyof T)[]) {
  return (target: new(...args: any[]) => T) => {
    // Do something with fields
  };
}

// works
@View('active', ['street1', 'street2'])
class Address {
  street1: string;
  street2: string;
}

// broken
@View('active', ['street1', 'street2'])
class AddressBroken {
  street1: string;
  street2?: string;
}

Expected behavior:
Both scenarios should work above.

Actual behavior:
It appears that optional fields are causing the decorator to create invalid types.

Argument of type 'typeof AddressBroken' is not assignable to parameter of type 'new (...args: any[]) => { street1: any; street2: any; }'.
  Type 'AddressBroken' is not assignable to type '{ street1: any; street2: any; }'.
    Property 'street2' is optional in type 'AddressBroken' but required in type '{ street1: any; street2: any; }'.
1234

Playground Link:
Playground Sample

Start with the linked Playground sample and reproduce the decorator error involving keyof, generic classes, and an optional field. Trace the compiler's handling of the decorator target type, then add a regression test covering both Address and AddressBroken and verify that both examples compile without the reported error.