If you are considering utilizing the Reflect API, there is a specific approach you must follow. Initially, it is essential to store the module information for the target class as metadata in a class decorator before accessing it in your method decorator.
UPDATE:
My initial solution turned out to be more complex than anticipated; I overlooked the fact that method decorators are evaluated prior to class decorators, requiring a workaround.
decorators.ts
import "reflect-metadata";
export function InjectModuleInfo (filename: string) {
return function <T extends { new (...args: any[]): {} }> (constructor: T) {
Reflect.defineMetadata("modulePath", filename, constructor);
}
}
export function MyMethodDecorator (target: any, propertyKey: string, descriptor: PropertyDescriptor) {
console.log(Reflect.getMetadata("modulePath", target.constructor));
}
TestClass.ts
import {MyClassDecorator, MyMethodDecorator} from './decorators';
@InjectModuleInfo(__filename)
class BaseClass {}
export class TestClass extends BaseClass {
@MyMethodDecorator
public myMethod () {}
}
For each class where this functionality is required, inheritance from a base class with the attached module info as metadata is necessary. Without this, if you directly apply the decorator to TestClass, the class decorator may not be processed in time for the method decorator.