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Vibe codingHardvc-g504
Subject Ai code reviewLevel Senior~18 minCommon in Algorithms & data structures interviewsIndustries Software development

Question

An AI wrote this DRF endpoint to apply a discount to an order. The serializer 'validates' the payload. Finance discovers orders with negative totals and 300% discounts. Explain why validation didn't stop it and fix it.

python
class DiscountSerializer(serializers.Serializer):    percent = serializers.FloatField()    reason = serializers.CharField() @api_view(["POST"])def apply_discount(request, order_id):    s = DiscountSerializer(data=request.data)    s.is_valid(raise_exception=True)    order = Order.objects.get(id=order_id)    order.total = order.total * (1 - s.validated_data["percent"] / 100)    order.save()    return Response({"total": str(order.total)})
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