deprecated.ts

import { illegalArgs } from "@thi.ng/errors";

/**
 * Method property decorator factory. Augments original method with
 * deprecation message (via console), shown when method is invoked.
 * Accepts optional message arg. Throws error if assigned property
 * is not a function.
 *
 * @param msg deprecation message
 */
export function deprecated(msg?: string, log = console.log): MethodDecorator {
    return function (target: any, prop: string | symbol, descriptor: PropertyDescriptor) {
        const signature = `${target.constructor.name}#${prop.toString()}`;
        const fn = descriptor.value;
        if (typeof fn !== "function") {
            illegalArgs(`${signature} is not a function`);
        }
        descriptor.value = function () {
            log(`DEPRECATED ${signature}: ${msg || "will be removed soon"}`);
            return fn.apply(this, arguments);
        };
        return descriptor;
    };
}