added event_emitter lib

src/lib/event_emitter/index.js

@@ -0,0 +1,65 @@
+export default class EventEmitter {
+    #events = {}
+
+    on = (eventName, listener) => {
+        if (!this.#events[eventName]) {
+            this.#events[eventName] = []
+        }
+
+        this.#events[eventName].push(listener)
+
+        return this
+    }
+
+    emit = (eventName, ...args) => {
+        if (!this.#events[eventName]) {
+            return false
+        }
+
+        this.#events[eventName].forEach((listener) => {
+            listener(...args)
+        })
+    }
+
+    off = (eventName, listener) => {
+        if (!this.#events[eventName]) {
+            return false
+        }
+
+        const index = this.#events[eventName].indexOf(listener)
+
+        if (index > -1) {
+            this.#events[eventName].splice(index, 1)
+        } else {
+            return false
+        }
+
+        return this
+    }
+
+    removeAllListeners = (eventName) => {
+        if (!this.#events[eventName]) {
+            return false
+        }
+
+        this.#events[eventName] = []
+
+        return this
+    }
+
+    awaitEmit = async (eventName, ...args) => {
+        if (!this.#events[eventName]) {
+            return false
+        }
+
+        await Promise.all(this.#events[eventName].map(async (listener) => {
+            await listener(...args)
+        }))
+
+        return this
+    }
+
+    hasEvent = (eventName) => {
+        return !!this.#events[eventName]
+    }
+}