如何使泛型类型约束变得不可思议

Question

我有这两个代码片段，如何更改它们，以便MemberModel可以作为泛型类型传递并保持可实例化，以便可以将follow方法提取到其自己的导出函数中？

export interface IFollowable {
    follow(user: IUserModel): IMemberModel;
}

export class CardModel implements ICardModel, IFollowable {
    public follow(user: IUserModel): IMemberModel {
        let member = new MemberModel({userId: user.id});
        member.role = UserRoles.follower;
        this.members.push(member);
        return member;
    }
}

我该如何进行关注和IFollowable泛型，以便我传递的任何类型都像MemberModel这样保持可更新状态？

Answer 1

这样我传递的任何类型都可以像MemberModel一样保持新状态

由于打字稿泛型在编译时会被删除，因此您需要显式传递它们，例如使用如下所示的工厂：

type User = {name:string};
type Member = {name: string};
type MemberCreator = {new (user:User): Member};

interface Followable {
    follow(user: User, memberCreator: MemberCreator): Member;
}

export class CardModel implements Followable {
    public follow(user: User, memberCreator: MemberCreator): Member {
       return new memberCreator(user);
    }
}