Chapter 8's RedisClient example

[peter-csala]

In chapter 8 (Async Streams >> Event Emitters, on pages 185-186) you have defined the following two types:

type Events = {    
  ready: void    
  error: Error    
  reconnecting: {
    delay: number, 
    attempt: number
    }
}

type RedisClient = {    
  on<E extends keyof Events>(event: E, f: (args: Events[E]) => void): void
}

I would like to have a naive implementation like this:

let Client: RedisClient = {        
  on<E extends keyof Events>(event: E, f: (args: Events[E]) => void) {
        if(event === "reconnecting") {
             f({delay: 1, attempt: 1})
        }    
    }
}
Client.on("reconnecting", (param :{delay: number, attempt: number}) => console.log(param.delay))

Unfortunately it gives me the following error (at this f({delay: 1, attempt: 1}) line):

Argument of type '{ delay: number; attempt: number; }' is not assignable to parameter of type 'Events[E]'.
  Type '{ delay: number; attempt: number; }' is not assignable to type 'void & Error & { delay: number; attempt: number; }'.
    Type '{ delay: number; attempt: number; }' is not assignable to type 'void'.(2345)

It seems like it uses intersection instead of union. How can I fix this?

I've found a related Typescript issue, but I couldn't manage to apply the suggested workaround in this example. Can you help me with this please?