useFieldArray resets form values after deleting item

Describe the bug All items appended to a field array are reset to the value given at append time when you delete an item from the stack.

To Reproduce Steps to reproduce the behavior:

1. Go to https://codesandbox.io/s/react-hook-form-usefieldarray-vy8fv
2. Click on the append button a few times
3. Change the text value of the second item
4. Delete the last item

Codesandbox link https://codesandbox.io/s/react-hook-form-usefieldarray-vy8fv

Expected behavior I would expect the value I entered into the textbox to remain after deleting another item from the array.

Screenshots If applicable, add screenshots to help explain your problem.

Desktop (please complete the following information):

• OS: Mac 10.14.6
• Browser: Chrome
• Version 79.0.3945.13

Additional context Interestingly enough, if you change the li key to test[${index}], it will retain the values when you delete an item from the stack. Unfortunately, this appears to have a similar issue. If you click append a couple of times, change the values to a, b, and c and then delete b, it will delete c instead.

Thank you for this wonderful little library! 🍻

[NoobTW]

had the same problem; fixed it by passing defaults AND ref={register()} (it didn’t work correctly with register acquired in the component via useFormContext.

Using ref={register()} instead of ref={register} works for me.

[miletich]

had the same problem; fixed it by passing defaults AND ref={register()} (it didn’t work correctly with register acquired in the component via useFormContext.