refactor

packages/frontend-shared/js/extract-avg-color-from-blurhash.ts

@@ -0,0 +1,14 @@
+/*
+ * SPDX-FileCopyrightText: syuilo and misskey-project
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+export function extractAvgColorFromBlurhash(hash: string) {
+	return typeof hash === 'string'
+		? '#' + [...hash.slice(2, 6)]
+			.map(x => '0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz#$%*+,-.:;=?@[]^_{|}~'.indexOf(x))
+			.reduce((a, c) => a * 83 + c, 0)
+			.toString(16)
+			.padStart(6, '0')
+		: undefined;
+}