strictNullChecks support

[danfinch]

With "strictNullChecks": true I encounter this error using the decorators from the test fixture:

  Type '(target: Object, propertyName?: string | undefined, parameterIndex?: number | undefined) => void' is not assignable to type 'PropertyDecorator'.
    Types of parameters 'propertyName' and 'propertyKey' are incompatible.
      Type 'string | symbol' is not assignable to type 'string | undefined'.
        Type 'symbol' is not assignable to type 'string | undefined'.
services.ts(65,12): error TS2322: Type '(...args: any[]) => (target: Object, propertyName?: string | undefined, parameterIndex?: number |...' is not assignable to type 'FieldDecoratorFactory'.
  Type '(target: Object, propertyName?: string | undefined, parameterIndex?: number | undefined) => void' is not assignable to type 'PropertyDecorator'.

I'll work around it but thought you might like to know!

[meirgottlieb]

Thanks. I'll take a look.