This is actually how react native constructs JS object from native module that exports some constants. All constants exported from getConstants method automatically become properties of the object.

Why is it an array of objects?

Not directly related to this diff but this type should be extracted and exist somewhere in lib/, we're starting to duplicate it in various places across codebase, e.g. type BackupAuth, type IdentityInfo.

I have a suspicion that @varun is using this one extensively too, maybe it's already done as a part of his work, cc @varun

yeah you can find this in lib/types/identity-service-types.js now

This is the beginning of JS definition of NativeEventEmitter class:

export default class NativeEventEmitter<TEventToArgsMap: {...}>
  implements IEventEmitter<TEventToArgsMap>

So it is typed by the map of event names to array of arguments that listener callbacks will take. Then addListener method takes as an argument callback function that is typed by unwinding the array passed to NatuveEventEmitter type:

addListener<TEvent: $Keys<TEventToArgsMap>>(
    eventType: TEvent,
    listener: (...args: $ElementType<TEventToArgsMap, TEvent>) => mixed,
    context?: mixed,
  )

In our case listener callback will take one argument so it is one-element array.