tsyringe 中的类型解析

Question

我最近开始使用tsyringe ，遇到了如何解决依赖关系的问题。 下面解释了一个可重现的场景：

class Client {
  exec(svcNum: number) {
    console.log("Executing ", svcNum);
  }
}

@injectable()
class Service1 {
  private readonly num = 1;
  constructor(private client: Client) {}
  serve() {
    this.client.exec(this.num);
  }
}

@injectable()
class Service2 {
  private readonly num = 2;
  constructor(private client: Client) {}
  serve() {
    this.client.exec(this.num);
  }
}

我有一个Client class ，它是Service1和Service2使用的依赖项。 这些可以像这样轻松解决：

const resolvedSvc1 = container.resolve(Service1);
const resolvedSvc2 = container.resolve(Service2);

现在我需要的是这样的：

container.register(Service1, { useClass: Service1 });
container.register(Service2, { useClass: Service2 });

const services = [ Service1, Service2 ]; // typeof Service1 | Service 2
services.forEach((svc) => {
  //container.register((svc as any).name, { useClass: svc });
  if (container.isRegistered((svc as any).name)) {
    console.log("Found registered service ", svc.name);
  }
  const resolved = container.resolve<typeof svc>(svc.name);
  (resolved as any).serve();
});

这不起作用，TypeScript 抱怨Error: Attempted to resolve unregistered dependency token: "Service1" ； 此外， console.log在if块中不打印任何内容。 我发现svc有一个联合类型Service1 | Service2 Service1 | Service2 ，这可能会导致问题。 有什么方法可以在运行时以这种方式动态解决服务的依赖关系？ 将svc缩小到适当的类型（即，我猜Service1或Service2都可以）。

Answer 1

您正在使用class注册您的服务，但随后尝试按name检索它们：

container.register(Service1, { useClass: Service1 });
//                 ^^^^^^^^ ✅ registering the class here

const resolved = container.resolve<typeof svc>(svc.name);
//                ❌ trying to resolve by name ^^^^^^^^

有两种解决方案：

// Option 1: register by class and resolve by class
container.register(Service1, { useClass: Service1 });
//                 ^^^^^^^^ ✅ register by class

const resolved = container.resolve<typeof svc>(svc);
//                         ✅ resolve by class ^^^

// Option 2: register using the class name and resolve by class or class name
container.register(Service1.name, { useClass: Service1 });
//                 ^^^^^^^^^^^^^ ✅ register by class name

// can resolve by class
const resolved = container.resolve<typeof svc>(svc);
//                         ✅ resolve by class ^^^

// can resolve by class name
const resolved = container.resolve<typeof svc>(svc.name);
//                        ✅ resolve by class name ^^^^