Typescript 如何创建一个将嵌套类属性的点表示法生成为字符串文字的类型

这与AWS SDK有关，它有几个客户端，每个客户端都有带有属性的命名空间.

这个库导出AWS，它有几个客户端，例如DynamoDB和ACM.DynamoDB有一个名为DocumentClient的房产.ACM有一个名为CertificateBody的房产.

class _DocumentClient {}
namespace _DocumentClient {}

// DynamoDB that is imported in the AWS module (see below)
declare class _DynamoDB {}
declare namespace _DynamoDB {
  export import DocumentClient = _DocumentClient;
}

// ACM client that is imported in the AWS module (see below)
declare class _ACM {}
declare namespace _ACM {
  export type CertificateBody = string;
}

// AWS module (mimicking)
// The original library (as linked above) exports a lot more clients...
namespace AWS {
  export import ACM = _ACM;
  export import DynamoDB = _DynamoDB;
}

我试图创建一个类型，它产生一个像"DynamoDB.DocumentClient" | "ACM.CertificateBody"这样的字符串字面量的联合.

我已经try 获取每个客户端的所有属性的列表，但这似乎是一项不可能完成的任务，更不用说使用点符号附加客户端和属性了.

我只得到了prototype个字符串，而不是想要的DocumentClient和CertificateBody个字符串.

// this works - ("ADM" | "DynamoDB")
type ClientName = keyof typeof AWS; 

// shouldn't this yield "DocumentClient" | "CertificateBody"? Using this type only means I can use "prototype" :/
type NestedClientName<C extends ClientName> = keyof typeof AWS[C]; 

// I want to be able to get a type with a union of string literals like `"ACM.CertificateBody" | "DynamoDB.DocumentClient" 
type NestedClientFullName<C extends ClientName, NC extends NestedClientName<C>> = `${C}.${NC}`; 

不幸的是，这NestedClientName个(因此，NestedClientFullName个)都没有产生公平的结果.

Here is a permalink to the full file on GitHub for context，以显示原始aws-sdk文件.我已经在上面的两个片段和下面的操场上复制了它.

Playground个