如何覆盖扩展记录的泛型类参数？

问：

我有一个和类。该类接受 2 个泛型参数：和 . 应该是某种类，而是以特定接口作为值的子集。现在，我的目标是创建子类，该子类将强制某些特定属性存在于 上，以便我可以强制使用该属性接口的某些自定义实现。ParentChildParentResultParentBuilderMapResultParentBuilderMapResultParentBuilderMap

我试图用 覆盖属性，但这会产生一个错误，指出这种类型不能分配给 ，我觉得这很奇怪，因为它将具有相同的键（或更多应该没问题）。Omit<A, keyof B> & BParentBuilderMap

下面是上述描述的演示实现

type Overwrite<A, B> = Omit<A, keyof B> & B;

interface Builder<Result> {
  build(): Result;
}

class SuperSecretBuilder implements Builder<string> {
  build() {
    return "lorem ipsum";
  }

  secret() {
    return "p4ssw0rd";
  }
}

type BuilderMap<Result> = Partial<Record<keyof Result, Builder<unknown>>>;

class Parent<Result, ParentBuilderMap extends BuilderMap<Result>> {
  doWork<Key extends keyof ParentBuilderMap>(key: Key, cb: () => ParentBuilderMap[Key]) {
    // tbd
  }
}

class Child<
  Result,
  ChildBuilderMap extends Overwrite<BuilderMap<Result>, { value: SuperSecretBuilder }>,
> extends Parent<Result, ChildBuilderMap> {
  doSecretWork() {
    // This method should resolve callback return value to SuperSecretBuilder based on provided key.
    this.doWork("value", () => {
      const builder = new SuperSecretBuilder();

      console.log(builder.secret());

      return builder;
    });
  }
}

和游乐场链接