How to spy on iterable

I want to spy on a simple array for a simple TypeScript class. However when I set up the test and run it I get an error saying 'createDiscounts is not iterable' How can I mock the iterable?

Here is the code:

       // discounts.ts
         export function createDiscounts {         
           discounts: number[] = [0.5, 0.4, 0.7, 0. 9]
           return discounts.entries()
    
          }

       export class ProcessDiscountedItemsService {
        
          applyDiscounts = (items: OrderItem) => {
          for(let [number, discount] of discounts){
            //do logic
          }
        }
      }

Here's my attempt to spy on the createDiscounts function

        import * as DiscountUtil from '../discounts.ts'
        describe('Process discount', () => {
        
        const service = new ProcessDiscountedItemsService()
        it('process item discounts verify' () =>{
            const items = ....
            const spy = (jest.spyOn(DiscountUtil, 'createDiscounts')) as jest.Mock
            const iteratable = [0.5, 0.4, 0.7, 0. 9].entries()
            service.applyDiscounts(items)
        })
     })

I replaced mockResolvedValueOnce with mockImplementation and that fixed the problem