Parameter Decorator

function ParameterDecorator(
    target: Function, // The prototype of the class
    propertyKey: string | symbol, // The name of the method
    parameterIndex: number // The index of parameter in the list of the function's parameters
    ) {
    console.log("ParameterDecorator called on: ", target, propertyKey, parameterIndex);
}

class ParameterDecoratorExample {
    method(@ParameterDecorator param1: string, @ParameterDecorator param2: number) {
    }
}

ParameterDecorator called on:  { method: [Function] } method 1
ParameterDecorator called on:  { method: [Function] } method 0