adds type checking to Animated toValue and iterations key values to m…

[andrew-schenk]

…ake sure Android does not crash from bad params when using useNativeDriver

Summary

Android apps crash when using Animated useNativeDriver: true and the toValue is not a number. See issue here with test case. Issue

Changelog

[Android] [fixed] - Fix crash when using Animated with useNativeDriver and a non Number toValue

Test Plan

Run Snack code with patched React Native core. Malformed parameters will no longer crash Android app.

[matthargett]

Should we show a warning in dev mode when this is the case? It a user has a bug in their JS, they may get confused when zeroes end up getting used silently.

[andrew-schenk]

My motivation for fixing this is that the JS bug is in one of possibly 100 different dependency libraries. Showing a warning might help focus attention on which library is the culprit or where in the internal project code the developer went awry. On the other hand, it might be another yellow box warning that gets silenced because the 3rd party lib is unsupported and the developer is tired of getting nagged about it.

Personally, I would probably want to see a warning and have the option of silencing it or fixing the library.

[AndrewSchenk]

The JavaScript animated version does not show a yellow box warning if you supply an invalid type. i.e.

toValue: null,
useNativeDriver: false

So to maintain parity between JS and native it would be best to not show a yellow box.

[cpojer]

Nice, thank you!

[facebook-github-bot]

@cpojer is landing this pull request. If you are a Facebook employee, you can view this diff on Phabricator.

[react-native-bot]

This pull request was successfully merged by @andrewschenk-linx in 25d3976.

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