📜 Description

Adds 10 unit tests for UUIDStringUtils, which previously had zero test coverage. This utility converts UUID and raw long values into Sentry's dash-free lowercase hex ID strings and is used internally by SentryId and SpanId.

Tests cover:

• toSentryIdString (32-char output): known UUID, all-zeros, all-ones, long-based overload consistency
• toSentrySpanIdString (16-char output): known UUID, all-zeros, all-ones, long-based overload consistency
• Structural invariants: output is always lowercase; span ID equals the first 16 characters of the full ID

💡 Motivation and Context

UUIDStringUtils is a foundational utility — if its hex encoding is wrong, every event ID and span ID in the SDK is wrong. Despite this, it had no dedicated tests. This is a test-only change with no production code modifications.

💚 How did you test it?

./gradlew :sentry:test --tests "*UUIDStringUtilsTest*"
# All 10 tests PASSED

./gradlew :sentry:spotlessApply
# Formatting clean

Reviewer checklist

• Verify the hardcoded expected hex strings match the input UUIDs with dashes stripped (e.g. a0eebc99-9c0b-4ef8-bb6d-6bb9bd380a11 → a0eebc999c0b4ef8bb6d6bb9bd380a11)
• Consider whether any additional edge cases are worth covering (e.g. UUID version/variant-specific bit patterns)

📝 Checklist

• I added GH Issue ID & Linear ID
• I added tests to verify the changes.
• No new PII added or SDK only sends newly added PII if sendDefaultPII is enabled.
• I updated the docs if needed.
• I updated the wizard if needed.
• Review from the native team if needed.
• No breaking change or entry added to the changelog.
• No breaking change for hybrid SDKs or communicated to hybrid SDKs.

🔮 Next steps

Other zero-coverage utility classes in sentry/util that could benefit from the same treatment: ClassLoaderUtils, ErrorUtils, Objects, Pair.

Link to Devin session: https://app.devin.ai/sessions/23aaff7eb99e45c79503152f36003ab8
Requested by: @aks4396