Validation for React.PropTypes.oneOf should compare values using Object.is

[chicoxyzzy]

...to check for NaN value proper.

also related to #6130

[chicoxyzzy]

should Object.is be polyfilled?

[chicoxyzzy]

Object.is``s caveat: do we really want +0to not be equal to-0`?

[zpao]

This seems reasonable. We've inlined Object.is in a couple places now (it's short) so we'll probably just do do that again.

[chicoxyzzy]

@zpao can you point me to such places? Maybe it's time to just use polyfill instead of inlining? :)

[zpao]

There was some discussion had elsewhere and at least at the time we were trying to avoid another polyfill.

https://github.com/facebook/fbjs/blob/52d3eeb9b156e7ebf578c7fe2b3f1eac76a0fd00/src/core/shallowEqual.js#L20-L32