feat: first release

event-emitter.ts

@@ -0,0 +1,39 @@
+import { EventEmitter as BaseEventEmitter } from "eventemitter3";
+
+export class EventEmitter<EventTypes extends ValidEventTypes = string | symbol> extends BaseEventEmitter<EventTypes> {
+  subscribe<T extends EventNames<EventTypes>>(
+    event: T,
+    fn: EventListener<EventTypes, T>,
+    destroy?: () => void,
+  ): {
+    unsubscribe: () => void;
+  } {
+    this.addListener(event, fn);
+    return {
+      unsubscribe: () => {
+        this.removeListener(event, fn);
+        if (destroy) {
+          destroy();
+        }
+      },
+    };
+  }
+}
+
+/*
+ |--------------------------------------------------------------------------------
+ | Types
+ |--------------------------------------------------------------------------------
+ */
+
+type EventListener<T extends ValidEventTypes, K extends EventNames<T>> = T extends string | symbol
+  ? (...args: any[]) => void
+  : (...args: ArgumentMap<Exclude<T, string | symbol>>[Extract<K, keyof T>]) => void;
+
+type EventNames<T extends ValidEventTypes> = T extends string | symbol ? T : keyof T;
+
+type ValidEventTypes = string | symbol | Record<string, unknown>;
+
+type ArgumentMap<T extends Record<string, unknown>> = {
+  [K in keyof T]: T[K] extends (...args: any[]) => void ? Parameters<T[K]> : T[K] extends any[] ? T[K] : any[];
+};