On Android, onValueChange is triggered on render when an item has a value of empty string

Describe the bug
onValueChange triggers immediately upon render, without having made any change. This only occurs on Android, with react-native-picker-select v5.2.3 and above

To Reproduce
In the items array passed to RNPickerSelect, if one of the items has a value of empty string, then onValueChange will trigger immediately upon render.

items array example for triggering the issue:

[
  { label: 'item', value: '3' },
  { label: 'item 2', value: '' },
]

Expected behavior
onValueChange should only trigger when a value changes.

Smartphone:

• OS: Android 5.1
• react-native-picker-select version: 5.2.4
• react-native version: 0.55.4
• react version: 16.3.1

Reproduction and/or code sample
https://snack.expo.io/SyFyj2DN4

[lfkwtz]

How bizarre - looks like the culprit was left: 0 when using the headless mode – which isn’t needed anyways.

Verify that #144 fixes it for you and i’ll merge it in.

There are some upstream picker issues on Android that have been fixed recently - this one may be related.

[zaytri]

Update! I was finally able to create a snack that reproduces this issue. As it turns out, it did not have to do with an empty array, but instead with a value of empty string, as I’ve now explained above. I’ve also figured out that it was a change in 5.2.3 that caused this issue to occur. I hope this helps!