Merge pull request #23 from jaredwray/adding-in-onceHook

adding in onceHook

README.md

@@ -150,6 +150,38 @@ myClass.onHook('before:myMethod2', async (data) => {
 });
 ```
 
+## .onceHook(eventName, handler)
+
+Subscribe to a hook event once.
+
+```javascript
+import { Hookified } from 'hookified';
+
+class MyClass extends Hookified {
+  constructor() {
+    super();
+  }
+
+  async myMethodWithHooks() Promise<any> {
+    let data = { some: 'data' };
+    // do something
+    await this.hook('before:myMethod2', data);
+
+    return data;
+  }
+}
+
+const myClass = new MyClass();
+
+myClass.onHookOnce('before:myMethod2', async (data) => {
+  data.some = 'new data';
+});
+
+myClass.myMethodWithHooks();
+
+console.log(myClass.hooks.length); // 0
+```
+
 ## .removeHook(eventName)
 
 Unsubscribe from a hook event.

src/index.ts

@@ -25,6 +25,21 @@ export class Hookified extends Eventified {
 		}
 	}
 
+	/**
+	 * Adds a handler that only executes once for a specific event
+	 * @param event
+	 * @param handler
+	 */
+	onceHook(event: string, handler: Hook) {
+		const hook = async (...arguments_: any[]) => {
+			this.removeHook(event, hook);
+			// eslint-disable-next-line @typescript-eslint/no-unsafe-argument
+			return handler(...arguments_);
+		};
+
+		this.onHook(event, hook);
+	}
+
 	/**
 	 * Removes a handler function for a specific event
 	 * @param {string} event

test/index.test.ts

@@ -20,6 +20,16 @@ describe('Hookified', () => {
 		expect(hookified.hooks.size).toBe(2);
 	});
 
+	test('onHookOnce will remove hook after execution', async () => {
+		const hookified = new Hookified();
+		// eslint-disable-next-line @typescript-eslint/no-empty-function
+		const handler = () => {};
+		hookified.onceHook('event', handler);
+		expect(hookified.getHooks('event')?.length).toEqual(1);
+		await hookified.hook('event');
+		expect(hookified.getHooks('event')?.length).toEqual(0);
+	});
+
 	test('onHook with Clear', async () => {
 		const hookified = new Hookified();
 		// eslint-disable-next-line @typescript-eslint/no-empty-function