fix: app crashing due to undefined settings constant accessor

[CalhamJNorthway]

The purpose of this PR is to fix a crash I found yesterday caused by an accessor that is undefined when newer versions of react native have Fabric enabled.

Our Build Setup:
react-native: v0.80.0
@launchdarkly/react-native-client-sdk: v10.1.5

Requirements

• add null coalescing operation to use getConstants to prevent undefined settings object
• still default to old accessor if not undefined

Related issues
I've not seen any related issues yet regarding your repo, though I did find this one Stack Overflow post.

Describe the solution you've provided
The solution I've provided is to use a null coalescing check to fallback to the new getConstants method on native modules if the settings object is undefined.

Describe alternatives you've considered
I searched to see if there are preferred alternatives and did not come up with any other solutions. I am open to feedback on that though :)

---

Note

Use a Fabric-safe iOS locale retrieval via SettingsManager.settings ?? SettingsManager.getConstants()?.settings, and add a lint:fix script.

• Locale handling (packages/sdk/react-native/src/platform/locale.ts)
  • Use Platform.select with iOS path resolving AppleLocale from SettingsManager.settings ?? SettingsManager.getConstants()?.settings; default to I18nManager.localeIdentifier.
  • Export the evaluated value via localeIdentifier().
• Tooling (packages/sdk/react-native/package.json)
  • Add lint:fix script.

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[kinyoklion]

@CalhamJNorthway Thank you for the PR!

What was the crash you are seeing? While I think that we need an update to reliably be accessing the locale, I don't see anything that was doing anything other than forwarding along the undefined value. Settings was undefined, but the app locale as already being conditionally accessed from it.

NativeModules.SettingsManager?.settings?.AppleLocale

Though there was a previous version where it looked like this:
NativeModules.SettingsManager?.settings.AppleLocale

Which would have crashed.

Thank you,
Ryan

[CalhamJNorthway]

@CalhamJNorthway Thank you for the PR!

What was the crash you are seeing? While I think that we need an update to reliably be accessing the locale, I don't see anything that was doing anything other than forwarding along the undefined value. Settings was undefined, but the app locale as already being conditionally accessed from it.

NativeModules.SettingsManager?.settings?.AppleLocale

Though there was a previous version where it looked like this: NativeModules.SettingsManager?.settings.AppleLocale

Which would have crashed.

Thank you, Ryan

Hey @kinyoklion, thanks for the prompt reply. I can add a little more detail, the issue was actually with the launch darkly client not instantiating correctly when the locale was undefined. You end up getting an error

Error initializing LaunchDarkly: TypeError: Cannot read property 'ldApplication' of undefined

Which after some further digging, I'm assuming was caused by the error below bubbling up to a higher error boundary

Error initializing LaunchDarkly: TypeError: Cannot read property 'AppleLocale' of undefined

Also for posterity, I have validated this fix with a node module patch on our application.
If you would like me to reproduce it with some screenshots I can do that tomorrow and post them here as a reply!

[joker23]

Thanks @CalhamJNorthway for the PR! Sorry for the delay in response, but I think this PR would be ready to merge after addressing my comments.