diff --git a/tests/utils.test.ts b/tests/utils.test.ts
new file mode 100644
index 0000000..ad74fab
--- /dev/null
+++ b/tests/utils.test.ts
@@ -0,0 +1,26 @@
+import { DiscordEnpoints } from '../utils/Constants'
+import { checkPerm, formatNumber } from '../utils/Tools'
+
+test('format Number', () => {
+	expect(formatNumber(1000)).toBe('1천')
+	expect(formatNumber(33333)).toBe('3.3만')
+	expect(formatNumber(600)).toBe('600')
+	expect(formatNumber(1300)).toBe('1천')
+	expect(formatNumber(9999)).toBe('1만')
+	expect(formatNumber(959999)).toBe('96만')
+	expect(formatNumber(999999)).toBe('100만')
+})
+
+test('checking Permission', () => {
+	expect(checkPerm(0x0, 0x0)).toBe(true)
+	expect(checkPerm(0x1, 0x2)).toBe(false)
+	expect(checkPerm(7, 'booster')).toBe(true)
+	expect(checkPerm(0, 'staff')).toBe(false)
+	expect(checkPerm(0x2, 'staff')).toBe(false)
+})
+
+test('check CDN URL', () => {
+	expect(DiscordEnpoints.CDN.user('000000000000000000', 'abcdefghijklm', { format: 'jpg', size: 1024 })).toBe('https://cdn.discordapp.com/avatars/000000000000000000/abcdefghijklm.jpg?size=1024')
+})
+
+export { }
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