typescript TS1241 : Unable to resolve signature of method decorator when called as an expression

Question

我的测试代码如下:

function test(target: Object, propertyKey: string, descriptor: TypedPropertyDescriptor<any>) {
    return descriptor;
}

class Test {
    @test
    hello() {
    }
}

但是编译器报错

Error:(33, 5) TS1241: Unable to resolve signature of method decorator when called as an expression.
 Supplied parameters do not match any signature of call target.

我已经指定: --experimentalDecorators --emitDecoratorMetadata

Answer 1

似乎 TypeScript 期望装饰器函数的返回类型为“any”或“void”。因此，在下面的示例中，如果我们将 : any 添加到末尾，它就会正常工作。

function test(target: Object, 
              propertyKey: string, 
              descriptor: TypedPropertyDescriptor<any>): any {
    return descriptor;
}