From df6f2c06d16b3ebfaa50e8d7f16cea5917b35bd2 Mon Sep 17 00:00:00 2001
From: Rory& <root@rory.gay>
Date: Tue, 25 Nov 2025 18:16:58 +0100
Subject: [PATCH] async filter extensions

---
 src/util/util/extensions/Array.test.ts |  6 ++++++
 src/util/util/extensions/Array.ts      | 10 ++++++++++
 2 files changed, 16 insertions(+)

diff --git a/src/util/util/extensions/Array.test.ts b/src/util/util/extensions/Array.test.ts
index 6395ddcf4..d41442c99 100644
--- a/src/util/util/extensions/Array.test.ts
+++ b/src/util/util/extensions/Array.test.ts
@@ -41,6 +41,12 @@ describe("Array extensions", () => {
 		assert.strictEqual(sum, 6);
 	});
 
+	it("filterAsync", async () => {
+		const arr = [1, 2, 3, 4, 5];
+		const even = await arr.filterAsync(async (n) => n % 2 === 0);
+		assert.deepEqual(even, [2, 4]);
+	});
+
 	it("remove", () => {
 		const arr = [1, 2, 3, 4, 5];
 		arr.remove(3);
diff --git a/src/util/util/extensions/Array.ts b/src/util/util/extensions/Array.ts
index 611a84373..c32b86ce8 100644
--- a/src/util/util/extensions/Array.ts
+++ b/src/util/util/extensions/Array.ts
@@ -22,6 +22,7 @@ declare global {
 		partition(filter: (elem: T) => boolean): [T[], T[]];
 		single(filter: (elem: T) => boolean): T | null;
 		forEachAsync(callback: (elem: T, index: number, array: T[]) => Promise<void>): Promise<void>;
+		filterAsync(callback: (elem: T, index: number, array: T[]) => Promise<boolean>): Promise<T[]>;
 		remove(item: T): void;
 		first(): T | undefined;
 		last(): T | undefined;
@@ -55,6 +56,11 @@ export async function arrayForEachAsync<T>(array: T[], callback: (elem: T, index
 	await Promise.all(array.map(callback));
 }
 
+export async function arrayFilterAsync<T>(array: T[], callback: (elem: T, index: number, array: T[]) => Promise<boolean>): Promise<T[]> {
+	const results = await Promise.all(array.map(callback));
+	return array.filter((_, index) => results[index]);
+}
+
 export function arrayRemove<T>(this: T[], item: T): void {
 	const index = this.indexOf(item);
 	if (index > -1) {
@@ -112,6 +118,10 @@ if (!Array.prototype.forEachAsync)
 	Array.prototype.forEachAsync = function <T>(this: T[], callback: (elem: T, index: number, array: T[]) => Promise<void>) {
 		return arrayForEachAsync(this, callback);
 	};
+if (!Array.prototype.filterAsync)
+	Array.prototype.filterAsync = function <T>(this: T[], callback: (elem: T, index: number, array: T[]) => Promise<boolean>) {
+		return arrayFilterAsync(this, callback);
+	};
 if (!Array.prototype.remove)
 	Array.prototype.remove = function <T>(this: T[], item: T) {
 		return arrayRemove.call(this, item);