fix native error on queryCorrelationSamples when no data available

[keima]

Hello,

This pull request fixes an issue where calling queryCorrelationSamples() for a given correlation type and date range could fail with the following HealthKit error when there were no matching samples in the specified period:

[Error: Error Domain=com.apple.healthkit Code=3 "The types argument may not be empty" UserInfo={NSLocalizedDescription=The types argument may not be empty}]

Repro case (React Native):

const result = await HealthKit.queryCorrelationSamples(
  'HKCorrelationTypeIdentifierBloodPressure',
  startDate,
  endDate
);

From my investigation (confirmed via Xcode), this error occurs when HealthKit attempts to execute the correlation query and there are effectively no types/objects to resolve for the given time window. Instead of returning an empty array, the native side surfaced this as an error.

When no items registered via HealthKit:

When some (four) items registered:

This PR adjusts the implementation of queryCorrelationSamples so that:

• In addition to when the correlations received from HealthKit are nil (null), I also made it so that it returns an empty array when an empty array is received.
• This change prevents errors that occur when an empty array is passed to store.preferredUnits.

As a result, consumers can safely call queryCorrelationSamples() without needing to special‑case this HealthKit error and can treat “no data” as an empty list.

[changeset-bot]

🦋 Changeset detected

Latest commit: 6678bcb

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 1 package

Name	Type
@kingstinct/react-native-healthkit	Patch

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npm i https://pkg.pr.new/kingstinct/react-native-healthkit/@kingstinct/react-native-healthkit@275

commit: 6678bcb

[keima]

Updated PR description (add Xcode debugging image, rewrite implementation points)

[robertherber]

Thanks @keima!