initial commit

patterns/factory.js

@@ -0,0 +1,60 @@
+'use strict';
+
+import _ from '../utils';
+
+const AbstractFactory = (function() {
+  let types = {};
+
+  return {
+    get(type, ...args) {
+      let constructor = types[type];
+
+      return constructor ? new constructor(...args) : null;
+    },
+    register(type, constructor) {
+      // We can check if the constructor fulfills the required
+      // pattern of types registered, for example
+      if (!constructor.prototype.hi) {
+        throw new Error('The provided constructor doesn\'t have the required `hi` method');
+      }
+
+      types[type] = constructor;
+
+      return AbstractFactory;
+    }
+  };
+}());
+
+class Boss {
+  constructor(name) {
+    this.name = name;
+  }
+
+  hi() {
+    return `Hello, ${this.name}`;
+  }
+}
+
+class Employee extends Boss {
+  constructor(name, role) {
+    super(name);
+    this.role = role;
+  }
+}
+
+class Invalid {
+  constructor() {
+    this.cantRegister = true;
+  }
+}
+
+AbstractFactory.register('Boss', Boss);
+AbstractFactory.register('Employee', Employee);
+let boss = AbstractFactory.get('Boss', 'John');
+_.log(boss.hi());
+
+try {
+  AbstractFactory.register('Invalid', Invalid);
+} catch (e) {
+  _.log('Caught error: ', e);
+}