CODE EXAMPLE FOR TYPESCRIPT

typescript combine interfaces

interface IClientRequestAndCoords extends IClientRequest, ICoords {} 

function(data: IClientRequestAndCoords) 

//OR

interface ClientRequest {
  userId:     number
  sessionKey: string
}

interface Coords {
  lat:  number
  long: number
}

function log(data: ClientRequest & Coords) { 
  console.log(
    data.userId,
    data.sessionKey,
    data.lat,
    data.long
  );
}