Add extended examples

tshemsedinov · tshemsedinov · commit f62fcd182b6a · 2018-09-15T23:21:35.000+03:00
diff --git a/JavaScript/3-extended.js b/JavaScript/3-extended.js
@@ -0,0 +1,34 @@
+'use strict';
+
+const listener = Parent => class extends Parent {
+  constructor() {
+    super();
+    this.events = {};
+  }
+  on(name, listener) {
+    const event = this.events[name];
+    if (event) event.push(listener);
+    else this.events[name] = [listener];
+  }
+  emit(name, ...data) {
+    const event = this.events[name];
+    if (!event) return;
+    event.forEach(fn => fn(...data));
+  }
+};
+
+const adder = Parent => class extends Parent {
+  constructor(initial) {
+    super();
+    this.value = initial;
+  }
+  add(value) {
+    this.value += value;
+    return this;
+  }
+};
+
+console.dir({
+  listener,
+  adder
+});
