Cleanup Part 2: Electric Boogaloo (Reloaded) (#594)

* Cleanup Part 2: Electric Boogaloo (Reloaded)

* Moar cleanup

* Tweak NOT_A_PERMISSION error

src/util/Collection.js

@@ -3,10 +3,9 @@
  * @extends {Map}
  */
 class Collection extends Map {
-
   /**
    * Returns an ordered array of the values of this collection.
-   * @returns {Array}
+   * @returns {*[]}
    * @example
    * // identical to:
    * Array.from(collection.values());
@@ -17,18 +16,19 @@ class Collection extends Map {
 
   /**
    * Returns the first item in this collection.
-   * @returns {Object}
+   * @returns {*}
    * @example
    * // identical to:
    * Array.from(collection.values())[0];
    */
   first() {
-    return this.array()[0];
+    return this.values().next().value;
   }
 
   /**
-   * Returns the last item in this collection.
-   * @returns {Object}
+   * Returns the last item in this collection. This is a relatively slow operation,
+   * since an array copy of the values must be made to find the last element.
+   * @returns {*}
    */
   last() {
     const arr = this.array();
@@ -36,8 +36,9 @@ class Collection extends Map {
   }
 
   /**
-   * Returns a random item from this collection.
-   * @returns {Object}
+   * Returns a random item from this collection. This is a relatively slow operation,
+   * since an array copy of the values must be made to find a random element.
+   * @returns {*}
    */
   random() {
     const arr = this.array();
@@ -47,32 +48,21 @@ class Collection extends Map {
   /**
    * If the items in this collection have a delete method (e.g. messages), invoke
    * the delete method. Returns an array of promises
-   * @returns {Array<Promise>}
+   * @returns {Promise[]}
    */
   deleteAll() {
     const returns = [];
     for (const item of this.values()) {
-      if (item.delete) {
-        returns.push(item.delete());
-      }
+      if (item.delete) returns.push(item.delete());
     }
     return returns;
   }
 
-  /**
-   * The length (size) of this collection.
-   * @readonly
-   * @type {number}
-   */
-  get length() {
-    return this.size;
-  }
-
   /**
    * Returns an array of items where `item[key] === value` of the collection
-   * @param {string} key the key to filter by
-   * @param {*} value the expected value
-   * @returns {Array<Object>}
+   * @param {string} key The key to filter by
+   * @param {*} value The expected value
+   * @returns {*[]}
    * @example
    * collection.getAll('username', 'Bob');
    */
@@ -81,18 +71,16 @@ class Collection extends Map {
     if (typeof value === 'undefined') throw new Error('value must be specified');
     const results = [];
     for (const item of this.values()) {
-      if (item[key] === value) {
-        results.push(item);
-      }
+      if (item[key] === value) results.push(item);
     }
     return results;
   }
 
   /**
    * Returns a single item where `item[key] === value`
-   * @param {string} key the key to filter by
-   * @param {*} value the expected value
-   * @returns {Object}
+   * @param {string} key The key to filter by
+   * @param {*} value The expected value
+   * @returns {*}
    * @example
    * collection.get('id', '123123...');
    */
@@ -100,17 +88,15 @@ class Collection extends Map {
     if (typeof key !== 'string') throw new TypeError('key must be a string');
     if (typeof value === 'undefined') throw new Error('value must be specified');
     for (const item of this.values()) {
-      if (item[key] === value) {
-        return item;
-      }
+      if (item[key] === value) return item;
     }
     return null;
   }
 
   /**
    * Returns true if the collection has an item where `item[key] === value`
-   * @param {string} key the key to filter by
-   * @param {*} value the expected value
+   * @param {string} key The key to filter by
+   * @param {*} value The expected value
    * @returns {boolean}
    * @example
    * if (collection.exists('id', '123123...')) {
@@ -121,32 +107,26 @@ class Collection extends Map {
     return Boolean(this.find(key, value));
   }
 
-  _arrayMethod(method, args) {
-    return Array.prototype[method].apply(this.array(), args);
-  }
-
   /**
    * Identical to
    * [Array.filter()](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/filter),
    * but returns a Collection instead of an Array.
-   * @param {function} callback the callback used to filter
-   * @param {Object} [thisArg] value to set as this when filtering
+   * @param {function} callback Function used to filter (should return a boolean)
+   * @param {Object} [thisArg] Value to set as this when filtering
    * @returns {Collection}
    */
   filter(...args) {
     const newArray = this.array().filter(...args);
     const collection = new Collection();
-    for (const item of newArray) {
-      collection.set(item.id, item);
-    }
+    for (const item of newArray) collection.set(item.id, item);
     return collection;
   }
 
   /**
    * Functionally identical shortcut to `collection.array().map(...)`.
-   * @param {function} callback Function that produces an element of the new Array, taking three arguments.
+   * @param {function} callback Function that produces an element of the new Array, taking three arguments
    * @param {*} [thisArg] Optional. Value to use as this when executing callback.
-   * @returns {array}
+   * @returns {*[]}
    */
   map(...args) {
     return this.array().map(...args);