fix(mixer): rewrite mixins management (#333)

* fix: declared properties

* fix: idk mixer

* fix(mixer): tbh I really hate runtimes

* fix: test

* test: change constructor test

src/deps/mixer.ts

@@ -1,75 +1,30 @@
-/**
- * Gets the descriptors of a class.
- * @param c The class to get the descriptors of.
- * @returns The descriptors of the class.
- */
-function getDenoDescriptors(c: TypeClass) {
-	const protos = [c.prototype];
-
-	let v = c;
-	while ((v = Object.getPrototypeOf(v))) {
-		if (v.prototype) protos.push(v.prototype);
+const IgnoredProps = ['constructor', 'prototype', 'name'];
+export function copyProperties(target: InstanceType<TypeClass>, source: TypeClass) {
+	const keys = Reflect.ownKeys(source);
+	for (const key of keys) {
+		if (IgnoredProps.includes(key as string)) continue;
+		if (key in target) continue;
+		const descriptor = Object.getOwnPropertyDescriptor(source, key);
+		if (descriptor) {
+			Object.defineProperty(target, key, descriptor);
+		}
 	}
-
-	return protos.map(x => Object.getOwnPropertyDescriptors(x));
 }
 
-/**
- * Gets the descriptors of a class.
- * @param c The class to get the descriptors of.
- * @returns The descriptors of the class.
- */
-function getNodeDescriptors(c: TypeClass) {
-	let proto = c.prototype;
-	const result: Record<string, TypedPropertyDescriptor<unknown> | PropertyDescriptor>[] = [];
-	while (proto) {
-		const descriptors = Object.getOwnPropertyDescriptors(proto);
-		// @ts-expect-error this is not a function in all cases
-		if (descriptors.valueOf.configurable) break;
-		result.push(descriptors);
-		proto = Object.getPrototypeOf(proto);
-	}
-	return result;
-}
-
-function getDescriptors(c: TypeClass) {
-	//@ts-expect-error
-	// biome-ignore lint/correctness/noUndeclaredVariables: <explanation>
-	return typeof Deno === 'undefined' ? getNodeDescriptors(c) : getDenoDescriptors(c);
-}
-
-/**
- * Mixes a class with other classes.
- * @param args The classes to mix.
- * @returns The mixed class.
- */
-export function Mixin<T, C extends TypeClass[]>(...args: C): C[number] & T {
-	const Base = args[0];
+export function Mixin<T, C extends TypeClass[]>(...mixins: C): C[number] & T {
+	const Base = mixins[0];
 
 	class MixedClass extends Base {
-		constructor(...constructorArgs: any[]) {
-			super(...constructorArgs);
-
-			for (const mixin of args.slice(1)) {
-				const descriptors = getDescriptors(mixin).reverse();
-				for (const desc of descriptors) {
-					// @ts-expect-error
-					Object.assign(this, new desc.constructor.value(...constructorArgs));
-					for (const key in desc) {
-						if (key === 'constructor') continue;
-						if (key in MixedClass.prototype) continue;
-						const descriptor = desc[key];
-
-						if (descriptor.value) {
-							// @ts-expect-error
-							MixedClass.prototype[key] = descriptor.value;
-						} else if (descriptor.get || descriptor.set) {
-							Object.defineProperty(MixedClass.prototype, key, {
-								get: descriptor.get,
-								set: descriptor.set,
-							});
-						}
-					}
+		constructor(...args: any[]) {
+			super(...args);
+			for (const mixin of mixins.slice(1)) {
+				// @ts-expect-error
+				const mixinInstance = new mixin(...args);
+				copyProperties(this, mixinInstance);
+				let proto = Object.getPrototypeOf(mixinInstance);
+				while (proto && proto !== Object.prototype) {
+					copyProperties(this, proto);
+					proto = Object.getPrototypeOf(proto);
 				}
 			}
 		}

src/structures/extra/Base.ts

@@ -3,7 +3,7 @@ import type { UsingClient } from '../../commands';
 import { toCamelCase } from '../../common';
 
 /** */
-export abstract class Base {
+export class Base {
 	constructor(client: UsingClient) {
 		Object.assign(this, { client });
 	}

tests/mixer.test.mts

@@ -138,7 +138,10 @@ describe('mix decorator', () => {
 
 	it('should handle constructor arguments', () => {
 		class MixinWithConstructor {
-			constructor(public name: string) {}
+			name: string;
+			constructor(name: string) {
+				this.name = name.slice(0, 2);
+			}
 
 			getName() {
 				return this.name;