diff --git a/locales/index.js b/locales/index.js
index 7399bb5a18..ac8ba19cfa 100644
--- a/locales/index.js
+++ b/locales/index.js
@@ -2,59 +2,90 @@
  * Languages Loader
  */
 
-const fs = require('fs');
-const yaml = require('js-yaml');
-let languages = []
-let languages_custom = []
-
-const merge = (...args) => args.reduce((a, c) => ({
-	...a,
-	...c,
-	...Object.entries(a)
-		.filter(([k]) => c && typeof c[k] === 'object')
-		.reduce((a, [k, v]) => (a[k] = merge(v, c[k]), a), {})
-}), {});
+const fs = require("fs");
+const yaml = require("js-yaml");
+const languages = [];
+const languages_custom = [];
 
+const merge = (...args) =>
+	args.reduce(
+		(a, c) => ({
+			...a,
+			...c,
+			...Object.entries(a)
+				.filter(([k]) => c && typeof c[k] === "object")
+				.reduce((a, [k, v]) => ((a[k] = merge(v, c[k])), a), {}),
+		}),
+		{},
+	);
 
 fs.readdirSync(__dirname).forEach((file) => {
-	if (file.includes('.yml')){
-		file = file.slice(0, file.indexOf('.'))
-		languages.push(file);
+	if (file.includes(".yml")) {
+		locale = file.slice(0, file.indexOf("."));
+		languages.push(locale);
 	}
-})
+});
 
-fs.readdirSync(__dirname + '/../custom/locales').forEach((file) => {
-	if (file.includes('.yml')){
-		file = file.slice(0, file.indexOf('.'))
-		languages_custom.push(file);
+fs.readdirSync(__dirname + "/../custom/locales").forEach((file) => {
+	if (file.includes(".yml")) {
+		customLocale = file.slice(0, file.indexOf("."));
+		languages_custom.push(customLocale);
 	}
-})
+});
 
 const primaries = {
-	'en': 'US',
-	'ja': 'JP',
-	'zh': 'CN',
+	en: "US",
+	ja: "JP",
+	zh: "CN",
 };
 
 // 何故か文字列にバックスペース文字が混入することがあり、YAMLが壊れるので取り除く
-const clean = (text) => text.replace(new RegExp(String.fromCodePoint(0x08), 'g'), '');
+const clean = (text) =>
+	text.replace(new RegExp(String.fromCodePoint(0x08), "g"), "");
 
-const locales = languages.reduce((a, c) => (a[c] = yaml.load(clean(fs.readFileSync(`${__dirname}/${c}.yml`, 'utf-8'))) || {}, a), {});
-const locales_custom = languages_custom.reduce((a, c) => (a[c] = yaml.load(clean(fs.readFileSync(`${__dirname}/../custom/locales/${c}.yml`, 'utf-8'))) || {}, a), {});
-Object.assign(locales, locales_custom)
+const locales = languages.reduce(
+	(a, c) => (
+		(a[c] =
+			yaml.load(clean(fs.readFileSync(`${__dirname}/${c}.yml`, "utf-8"))) ||
+			{}),
+		a
+	),
+	{},
+);
+const locales_custom = languages_custom.reduce(
+	(a, c) => (
+		(a[c] =
+			yaml.load(
+				clean(
+					fs.readFileSync(`${__dirname}/../custom/locales/${c}.yml`, "utf-8"),
+				),
+			) || {}),
+		a
+	),
+	{},
+);
+Object.assign(locales, locales_custom);
 
-module.exports = Object.entries(locales)
-	.reduce((a, [k ,v]) => (a[k] = (() => {
-		const [lang] = k.split('-');
-		switch (k) {
-			case 'ja-JP': return v;
-			case 'ja-KS':
-			case 'en-US': return merge(locales['ja-JP'], v);
-			default: return merge(
-				locales['ja-JP'],
-				locales['en-US'],
-				locales[`${lang}-${primaries[lang]}`] || {},
-				v
-			);
-		}
-	})(), a), {});
+module.exports = Object.entries(locales).reduce(
+	(a, [k, v]) => (
+		(a[k] = (() => {
+			const [lang] = k.split("-");
+			switch (k) {
+				case "ja-JP":
+					return v;
+				case "ja-KS":
+				case "en-US":
+					return merge(locales["ja-JP"], v);
+				default:
+					return merge(
+						locales["ja-JP"],
+						locales["en-US"],
+						locales[`${lang}-${primaries[lang]}`] || {},
+						v,
+					);
+			}
+		})()),
+		a
+	),
+	{},
+);