fix: improve unit tests style

tests/members/avatarlUrl.ts

@@ -0,0 +1,14 @@
+import { assertEquals } from "../deps.ts";
+import { bot } from "../mod.ts";
+
+Deno.test({
+    name: "[member] format a members avatar url",
+    fn: async (t) => {
+      assertEquals(
+        bot.helpers.avatarURL(130136895395987456n, 8840, {
+          avatar: 4055337350987360625717955448021200177333n,
+        }),
+        "https://cdn.discordapp.com/avatars/130136895395987456/eae5905ad2d18d7c8deca20478b088b5.jpg?size=128"
+      );
+    },
+  });