EJS Exercise - The locked box.js

// http://eloquentjavascript.net/08_error.html

var box = {
  locked: true,
  unlock: function() { this.locked = false; },
  lock: function() { this.locked = true;  },
  _content: [],
  get content() {
    if (this.locked) throw new Error("Locked!");
    return this._content;
  }
};

function withBoxUnlocked(body) {
  	var isUnlocked = !box.locked;
	try {
      box.unlock();
      body();
    } catch (e) {
      console.log(e);
    } finally {
      if (!isUnlocked) {
	      box.lock();
      }
    } 
}

withBoxUnlocked(function() {
  box.content.push("gold piece");
});

try {
  withBoxUnlocked(function() {
    throw new Error("Pirates on the horizon! Abort!");
  });
} catch (e) {
  console.log("Error raised:", e);
}
console.log(box.locked);
// → true