Proxy-hookified NPM

⚓ proxy-hooks

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Philosophy

I built this pkg with the primary intention of making the use of Proxy simple and easy. Additionally it also provides the functionality api of other projects like tinyspy and nanospy via the hooks methodArguments and methodReturn

Usage

import Spy from "proxy-hooks";
const originalSource = {
  name: "Joe",
  printName(name) {
    return name;
  },
  printObjName() {
    return this.name;
  },
}; // originalSource can also be a function
const handler = {
  canGet() {
    return true;
  },
  tapGet(target, prop, receiver) {
    return Reflect.get(...arguments);
  },
  methodArguments(cachedInfo, args) {
    args[0] = args[0] + "Wallace";
    return args;
  },
  methodReturn(cachedInfo, returnVal) {
    if (cachedInfo.propName === "printObjName") {
      return "Joe Biden Modified";
    }
    return returnVal;
  },
};
const [proxy, revokeProxy] = Spy(orignalSource, handler);
expect(obj.printName("Jipy")).toBe("JipyWallace");
expect(obj.printObjName()).toBe("Joe Biden Modified");
revokeProxy.revoke();

The Handler object has the following type signature. It can accept other native proxy methods as well other than get,set and apply.

type Handler<T extends Object> = Partial<
  {
    canGet: (descriptor: Descriptor) => boolean;
    canSet: (descriptor: Descriptor, oldValue: any, newValue: any) => boolean;
    tapGet: TapSignature<T>;
    tapSet: TapSignature<T>;
    methodArguments: (
      cachedKnowledge: {
        propName: string | symbol;
        calls: number;
        results: any[];
      },
      args: any[],
    ) => any[];
    methodReturn: (
      cachedKnowledge: {
        propName: string | symbol;
        calls: number;
        results: any[];
      },
      result: any,
    ) => any | void;
  } & Omit<ProxyHandler<T>, "get" | "set" | "apply">
>;

Checks its types.d.ts file for complete API.