Actually included the file

src/class/Collection.ts

@@ -0,0 +1,188 @@
+/**
+ * Hold a bunch of something
+ */
+export default class Collection<V> extends Map<string, V> {
+  baseObject: any
+
+  iterable: any[]|object
+
+  /**
+   * Creates an instance of Collection
+   */
+  constructor({ base: baseObject = null, iterable = null }) {
+    if (iterable && iterable instanceof Array) {
+      // @ts-ignore
+      super(iterable);
+    } else if (iterable && iterable instanceof Object) {
+      // @ts-ignore
+      super(Object.entries(iterable));
+    } else {
+      super();
+    }
+    this.baseObject = baseObject;
+  }
+
+  /**
+   * Map to array
+   * ```js
+   * [value, value, value]
+   * ```
+   */
+  toArray(): V[] {
+    return [...this.values()];
+  }
+
+  /**
+   * Map to object
+   * ```js
+   * { key: value, key: value, key: value }
+   * ```
+   */
+  toObject(): object {
+    const obj: object = {};
+    for (const [key, value] of this.entries()) {
+      obj[key] = value;
+    }
+    return obj;
+  }
+
+  /**
+   * Add an object
+   *
+   * If baseObject, add only if instance of baseObject
+   *
+   * If no baseObject, add
+   * @param key The key of the object
+   * @param value The object data
+   * @param replace Whether to replace an existing object with the same key
+   * @return The existing or newly created object
+   */
+  add(key: string, value: V, replace: boolean = false): V {
+    if (this.has(key) && !replace) {
+      return this.get(key);
+    }
+    if (this.baseObject && !(value instanceof this.baseObject)) return null;
+
+    this.set(key, value);
+    return value;
+  }
+
+  /**
+   * Return the first object to make the function evaluate true
+   * @param func A function that takes an object and returns something
+   * @return The first matching object, or `null` if no match
+   */
+  find(func: Function): V {
+    for (const item of this.values()) {
+      if (func(item)) return item;
+    }
+    return null;
+  }
+
+  /**
+   * Return an array with the results of applying the given function to each element
+   * @param func A function that takes an object and returns something
+   */
+  map(func: Function) {
+    const arr = [];
+    for (const item of this.values()) {
+      arr.push(func(item));
+    }
+    return arr;
+  }
+
+  /**
+   * Return all the objects that make the function evaluate true
+   * @param func A function that takes an object and returns true if it matches
+   */
+  filter(func: Function): V[] {
+    const arr = [];
+    for (const item of this.values()) {
+      if (func(item)) {
+        arr.push(item);
+      }
+    }
+    return arr;
+  }
+
+  /**
+   * Reduce values by function
+   * @param callbackFn Function to execute on each element in the array
+   * @param initialValue Value to use as the first argument to the first call of the callback
+   * @returns Accumulator
+   */
+  reduce(func: Function, initialValue = 0) {
+    const iter = this.values();
+    let val;
+    let result = initialValue === undefined ? iter.next().value : initialValue;
+    while ((val = iter.next().value) !== undefined) { // eslint-disable-line
+      result = func(result, val);
+    }
+    return result;
+  }
+
+  /**
+   * Test if at least one element passes the test implemented by the provided function. Returns true if yes, or false if not.
+   * @param func A function that takes an object and returns true if it matches
+   */
+  some(func: Function) {
+    for (const item of this.values()) {
+      if (func(item)) {
+        return true;
+      }
+    }
+    return false;
+  }
+
+  /**
+   * Test if all elements passe the test implemented by the provided function. Returns true if yes, or false if not.
+   * @param func A function that takes an object and returns true if it matches
+   * @returns An array containing booleans that matched
+   */
+  every(func: Function): boolean[] {
+    const array = [];
+    for (const item of this.values()) {
+      if (func(item)) array.push(true);
+      else array.push(false);
+    }
+    return array;
+  }
+
+  /**
+   * Update an object
+   * @param key The key of the object
+   * @param value The updated object data
+   */
+  update(key: string, value: V) {
+    return this.add(key, value, true);
+  }
+
+  /**
+   * Remove an object
+   * @param key The key of the object
+   * @returns The removed object, or `null` if nothing was removed
+   */
+  remove(key): V {
+    const item = this.get(key);
+    if (!item) {
+      return null;
+    }
+    this.delete(key);
+    return item;
+  }
+
+  /**
+   * Get a random object from the Collection
+   * @returns The random object or `null` if empty
+   */
+  random(): V {
+    if (!this.size) {
+      return null;
+    }
+    return Array.from(this.values())[Math.floor(Math.random() * this.size)];
+  }
+
+  toString() {
+    return `[Collection<${this.baseObject.name}>]`;
+  }
+}