I have to override following WooCommerce core class methods:
What I'm trying to do is WooCommerce does not allow to have a non-sale product and a sale product in the cart and then apply the coupon code.
When the following option is checked on coupon
Usage restriction tab
Check this box if the coupon should not apply to items on sale. Per-item coupons will only work if the item is not on sale. Per-cart coupons will only work if there are no sale items in the cart.
I have to make coupon applied to only non-sale products even if any sale products in the cart. The coupon will only affect non-sale products amount and simply ignore sale products amount.
Now I got workaround with this thing and I have to override with my own custom implementation with above methods. And as you see there are no hooks to work with either.
I also tried this solution without any luck