proxy-enumerable-console-log.ts

// Target object
const target = {
  foo: 1,
  bar: 2,
};

// Fallback object
const fallback = {
  bar: 20, // This will be overridden by target's bar
  baz: 3,
  [Symbol('qux')]: 4,
};

// Apply a proxy
const proxy = new Proxy(target, {
  // Intercept property access
  get(target, property, receiver) {
    if (property in target) {
      return Reflect.get(target, property, receiver);
    } else if (property in fallback) {
      return Reflect.get(fallback, property, receiver);
    }
    return undefined; // Return undefined if not found
  },

  // Intercept ownKeys to include keys from both target and fallback
  ownKeys(target) {
    const targetKeys = Reflect.ownKeys(target);
    const fallbackKeys = Reflect.ownKeys(fallback);
    return Array.from(new Set([...targetKeys, ...fallbackKeys]));
  },

  // Intercept getOwnPropertyDescriptor to handle keys from both target and fallback
  getOwnPropertyDescriptor(target, property) {
    if (Reflect.has(target, property)) {
      return Reflect.getOwnPropertyDescriptor(target, property);
    } else if (Reflect.has(fallback, property)) {
      // Return a property descriptor that makes the property enumerable and configurable
      const descriptor = Reflect.getOwnPropertyDescriptor(fallback, property);
      return {
        ...descriptor,
        configurable: true, // Ensure the property can be modified or deleted
        enumerable: true,   // Ensure the property shows up in enumerations
      };
    }
    return undefined;
  }
});

// Example usage
console.log({ proxy });
// Deno Prints: { proxy: { foo: 1, bar: 2, baz: 3, [Symbol(qux)]: 4 } }
// Node.js & Bun Prints: { proxy: { foo: 1, bar: 2 } }
// Chrome & Safari Print: { proxy: Proxy {foo: 1, bar: 2} }
// Firefox Prints: Object { proxy: Proxy }