Fix coupon infolist enum formatting

tests/Unit/CouponInfolistTest.php

@@ -0,0 +1,19 @@
+<?php
+
+namespace Tests\Unit;
+
+use App\Enums\CouponStatus;
+use App\Enums\CouponType;
+use App\Filament\Resources\Coupons\Schemas\CouponInfolist;
+use Tests\TestCase;
+
+class CouponInfolistTest extends TestCase
+{
+    public function test_it_formats_enum_states(): void
+    {
+        $this->assertSame(CouponType::PERCENTAGE->label(), CouponInfolist::formatEnumState(CouponType::PERCENTAGE));
+        $this->assertSame(CouponStatus::ACTIVE->label(), CouponInfolist::formatEnumState(CouponStatus::ACTIVE));
+        $this->assertSame('Flat', CouponInfolist::formatEnumState('flat'));
+        $this->assertSame('', CouponInfolist::formatEnumState(null));
+    }
+}