initial commit

assets/pubsub.js

@@ -0,0 +1,25 @@
+let subscribers = {};
+
+function subscribe(eventName, callback) {
+  if (subscribers[eventName] === undefined) {
+    subscribers[eventName] = [];
+  }
+
+  subscribers[eventName] = [...subscribers[eventName], callback];
+
+  return function unsubscribe() {
+    subscribers[eventName] = subscribers[eventName].filter((cb) => {
+      return cb !== callback;
+    });
+  };
+}
+
+function publish(eventName, data) {
+  if (subscribers[eventName]) {
+    const promises = subscribers[eventName]
+      .map((callback) => callback(data))
+    return Promise.all(promises);
+  } else {
+    return Promise.resolve()
+  }
+}