From fa0672ee64bacc46ff98f478be68a5afa79b947f Mon Sep 17 00:00:00 2001
From: Andi Wilson <andiwils@cisco.com>
Date: Thu, 6 Jun 2024 14:42:31 -0700
Subject: [PATCH] feat: add method to remove all listeners

---
 src/event-mixin.spec.ts | 34 ++++++++++++++++++++++++++++++++++
 src/event-mixin.ts      | 12 ++++++++++++
 src/typed-event.ts      |  7 +++++++
 3 files changed, 53 insertions(+)

diff --git a/src/event-mixin.spec.ts b/src/event-mixin.spec.ts
index 36a4e60..454ef5c 100644
--- a/src/event-mixin.spec.ts
+++ b/src/event-mixin.spec.ts
@@ -42,6 +42,22 @@ describe('a class with events', () => {
     expect(handlerTwoArgs).toHaveLength(1);
     expect(handlerTwoArgs[0]).toBe(42);
   });
+
+  it('should remove all handlers when removeAllListeners is called', () => {
+    expect.hasAssertions();
+    const handlerOneArgs: number[] = [];
+    const handler = (value: number) => {
+      handlerOneArgs.push(value);
+    };
+    myClass.on('eventOne', handler);
+    myClass.fireEventOne();
+    expect(handlerOneArgs).toHaveLength(1);
+    expect(handlerOneArgs[0]).toBe(42);
+
+    myClass.removeAllListeners();
+    myClass.fireEventOne();
+    expect(handlerOneArgs).toHaveLength(1); // Should still be 1, as all listeners should be removed
+  });
 });
 
 interface ChildEvents {
@@ -75,4 +91,22 @@ describe('a child class', () => {
     expect(eventOneArgs).toHaveLength(1);
     expect(eventThreeArgs).toHaveLength(1);
   });
+
+  it('should remove all handlers from parent and child when removeAllListeners is called', () => {
+    expect.hasAssertions();
+
+    const eventOneArgs: number[] = [];
+    const eventThreeArgs: string[] = [];
+
+    myClass.on('eventOne', (value: number) => eventOneArgs.push(value));
+    myClass.on('eventThree', (value: string) => eventThreeArgs.push(value));
+
+    myClass.removeAllListeners();
+
+    myClass.fireEventOne();
+    myClass.fireEventThree();
+
+    expect(eventOneArgs).toHaveLength(0); // Should be 0, as all listeners should be removed
+    expect(eventThreeArgs).toHaveLength(0); // Should be 0, as all listeners should be removed
+  });
 });
diff --git a/src/event-mixin.ts b/src/event-mixin.ts
index b3b0a72..324a044 100644
--- a/src/event-mixin.ts
+++ b/src/event-mixin.ts
@@ -63,6 +63,18 @@ export function AddEvents<TBase extends Constructor, U>(Base: TBase) {
     off<K extends keyof U, E extends eventHandlerType<U[K]>>(eventName: K, handler: E) {
       (this as any)[eventName].off(handler);
     }
+
+    /**
+     * Remove all event listeners from all events.
+     */
+    removeAllListeners() {
+      Object.keys(this).forEach((eventName) => {
+        const event = (this as any)[eventName];
+        if (event instanceof TypedEvent) {
+          event.removeAllListeners();
+        }
+      });
+    }
   };
 }
 
diff --git a/src/typed-event.ts b/src/typed-event.ts
index 3189c6d..eb2155d 100644
--- a/src/typed-event.ts
+++ b/src/typed-event.ts
@@ -57,4 +57,11 @@ export class TypedEvent<T extends Handler> {
   emit(...args: Parameters<T>): void {
     this.emitter.emit('event', ...args);
   }
+
+  /**
+   * Remove all listeners from this event.
+   */
+  removeAllListeners(): void {
+    this.emitter.removeAllListeners('event');
+  }
 }