Adding in prepend functionality on hooks

README.md

@@ -182,6 +182,66 @@ myClass.myMethodWithHooks();
 console.log(myClass.hooks.length); // 0
 ```
 
+## .prependHook(eventName, handler)
+
+Subscribe to a hook event before all other hooks.
+
+```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.onHook('before:myMethod2', async (data) => {
+  data.some = 'new data';
+});
+myClass.preHook('before:myMethod2', async (data) => {
+  data.some = 'will run before new data';
+});
+```
+
+## .prependOnceHook(eventName, handler)
+
+Subscribe to a hook event before all other hooks. After it is used once it will be removed.
+
+```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.onHook('before:myMethod2', async (data) => {
+  data.some = 'new data';
+});
+myClass.preHook('before:myMethod2', async (data) => {
+  data.some = 'will run before new data';
+});
+```
+
 ## .removeHook(eventName)
 
 Unsubscribe from a hook event.

package.json

@@ -1,6 +1,6 @@
 {
   "name": "hookified",
-  "version": "1.5.1",
+  "version": "1.6.0",
   "description": "Event and Middleware Hooks",
   "type": "module",
   "main": "dist/node/index.cjs",

src/index.ts

@@ -25,6 +25,36 @@ export class Hookified extends Eventified {
 		}
 	}
 
+	/**
+	 * Adds a handler function for a specific event that runs before all other handlers
+	 * @param {string} event
+	 * @param {Hook} handler - this can be async or sync
+	 * @returns {void}
+	 */
+	prependHook(event: string, handler: Hook) {
+		const eventHandlers = this._hooks.get(event);
+		if (eventHandlers) {
+			eventHandlers.unshift(handler);
+		} else {
+			this._hooks.set(event, [handler]);
+		}
+	}
+
+	/**
+	 * Adds a handler that only executes once for a specific event before all other handlers
+	 * @param event
+	 * @param handler
+	 */
+	prependOnceHook(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.prependHook(event, hook);
+	}
+
 	/**
 	 * Adds a handler that only executes once for a specific event
 	 * @param event

test/index.test.ts

@@ -138,4 +138,49 @@ describe('Hookified', () => {
 		await hookified.hook('event', data);
 		expect(data.key).toBe('modified');
 	});
+
+	test('prepends hook to the beginning of the array', async () => {
+		const hookified = new Hookified();
+		const handlerData: string[] = [];
+
+		const handler = () => {
+			handlerData.push('modified2');
+		};
+
+		const handler2 = () => {
+			handlerData.push('modified1');
+		};
+
+		hookified.onHook('event', handler);
+		hookified.prependHook('event', handler2);
+		await hookified.hook('event');
+		expect(handlerData[0]).toBe('modified1');
+		expect(handlerData[1]).toBe('modified2');
+	});
+
+	test('prepends hook and creates new array', async () => {
+		const hookified = new Hookified();
+		const handlerData: string[] = [];
+
+		const handler = () => {
+			handlerData.push('modified1');
+		};
+
+		hookified.prependHook('event', handler);
+		await hookified.hook('event');
+		expect(handlerData[0]).toBe('modified1');
+	});
+
+	test('prepends a hook and removes it', async () => {
+		const hookified = new Hookified();
+		const handlerData: string[] = [];
+
+		const handler = () => {
+			handlerData.push('modified1');
+		};
+
+		hookified.prependOnceHook('event20', handler);
+		await hookified.hook('event20');
+		expect(hookified.hooks.get('event20')?.length).toBe(0);
+	});
 });