Safely extending built in objects prototype javascript

Hard

How to Safely Extend JavaScript Built-in Prototypes for a Plugin System

You're building a plugin system that needs to safely extend built-in objects. What's wrong with this implementation and which solution correctly fixes the issues?

Choose an option below

function installPlugin(pluginName, methods) {
  const target = targets[pluginName];
  Object.defineProperties(
    target,
    Object.entries(methods).reduce((acc, [name, fn]) => {
      if (!(name in target)) {
        acc[name] = {
          value: fn,
          writable: true,
          configurable: true,
          enumerable: false
        };
      }
      return acc;
    }, {})
  );
}

function installPlugin(pluginName, methods) {
  const target = targets[pluginName];
  for (const [name, fn] of Object.entries(methods)) {
    if (!target[name]) {
      target[name] = fn;
    }
  }
}

function installPlugin(pluginName, methods) {
  const CustomClass = function() {};
  CustomClass.prototype = targets[pluginName];
  Object.assign(CustomClass.prototype, methods);
  return new CustomClass();
}

function installPlugin(pluginName, methods) {
  const symbol = Symbol(pluginName);
  targets[pluginName][symbol] = methods;
  Object.keys(methods).forEach(methodName => {
    if (!targets[pluginName][methodName]) {
      targets[pluginName][methodName] = 
        function(...args) {
          return this[symbol][methodName].apply(this, args);
        };
    }
  });
}

JavascriptPrototypesObject propertiesInheritanceProperty descriptors

1function installPlugin(pluginName, methods) {
const targets = {
  array: Array.prototype,
  string: String.prototype,
  number: Number.prototype
};

// Current problematic implementation
Object.keys(methods).forEach(methodName => {
  if (!targets[pluginName][methodName]) {
    targets[pluginName][methodName] = methods[methodName];
  }
});
14}
15
16// Usage example:
17installPlugin('array', {
last() {
  return this[this.length - 1];
},
random() {
  return this[Math.floor(Math.random() * this.length)];
}
24});

How to Safely Extend JavaScript Built-in Prototypes for a Plugin System

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