Lunar version: 1.0.0‑beta.24
Laravel Version: 11.45.1
PHP Version: 8.2.28
Database Driver & Version: MySQL 8

Expected Behaviour:

Coupon codes should be either case‑insensitive or explicitly enforced as uppercase. The validator should reject any code entered in lowercase at creation time, or automatically convert it to uppercase ( in admin panel ).

For example:
Admin tries to save code test10 → validation error “Only uppercase letters and numbers allowed.”

Or admin enters test10 and it’s auto‑uppercased to TEST10 on save.

Actual Behaviour

• Lowercase coupon codes (e.g., test10) can be created and saved in the admin panel without any warning.

• When such a lowercase code (test10) is applied programmatically using:

  $this->cart->update([
    'coupon_code' => 'test10',
  ]);

  — it succeeds.

• However, if you try to apply the same code with an uppercase letter (e.g., Test10):

  $this->cart->update([
    'coupon_code' => 'Test10',
  ]);

  — it fails.

• method Discounts::validateCoupon returns true for both 'test10' and 'Test10'.

Steps To Reproduce:

1. Create a coupon code in the admin panel
   Go to the admin panel and create a new discount with a lowercase code, e.g., test10. Save it.

2. Apply the coupon code programmatically (lowercase)
   In your code, update the cart using:

   $this->cart->update([
     'coupon_code' => 'test10',
   ]);

   The coupon is applied successfully.

3. Apply the coupon code programmatically (different capitalization)
   Now, try updating the cart using:

   $this->cart->update([
     'coupon_code' => 'Test10',
   ]);

   The operation fails—the coupon is not applied.

4. Validate the coupon code with both cases
   Call the validation method for both variants:

   Discounts::validateCoupon('test10'); // returns true
   Discounts::validateCoupon('Test10'); // also returns true

   Both validations succeed, even though only the lowercase variant works when applying the coupon.