I was able to create duplicates about woocommerce-coupon-generator

[JeroenSormani]

Hey @INOVEK,

Correct, it is possible duplicate coupons are generated. The changes to that are quite small though as there are 62¹² (thats, like, a million-gazillion-empirerillion) possibilities, so I don't tend worry too much about those odds ;-)

Adding a check for existing coupons would give a huge slow down on the generation of the coupons (I've done a sh*t ton of testing and optimization on the generation process, including a check for existing coupon codes :-)

[nemeth-it]

But I think it would be a good idea to add this option. Especially when you allow in the future to change the length of the coupon-code and add prefixes, then a toggleable option would be nice.

Just because you say the possibilitie for this is quite small, so that it wouldn't happen. (it still remains possible)

[JeroenSormani]

I'll take it in consideration as a option, but can't guarantee it.
So far I've not been very convinced of the amount of added value of it (I'm very careful with adding options to keep my plugins clean & lean).

Even when it happens that a duplicate coupon code is generated, the impact of that is almost irrelevant I believe.. (correct me if I'm wrong)