test: Add Comprehensive Unit Tests for WALConfirmOffsetCalculator

[godsboy404]

Problem Description

The WALConfirmOffsetCalculator class lacked comprehensive unit tests to validate its functionality, especially for edge cases and concurrent scenarios. This could lead to potential undetected bugs in the calculation of confirmed offsets in the Write-Ahead Log (WAL).

Changes Made

1. Added Unit Tests:

• Verified initial state and behavior with an empty queue.
• Tested scenarios with single and multiple confirmed/unconfirmed requests.
• Covered edge cases such as gaps in confirmations, out-of-order confirmations, and very large/zero offsets.
• Ensured processed requests are removed from the queue after confirmation.
• Validated thread safety and concurrent operations using multiple threads.
• Confirmed that the addLock method provides a read lock for concurrent access.

2. Test Coverage:

• Edge cases: Large offsets, zero offsets, and interleaved confirmed/unconfirmed requests.
• Concurrency: Simulated concurrent additions and updates to ensure thread safety.
• Performance: Verified the algorithm's behavior under high load and large datasets.

3. Helper Methods:

• Created utility methods to simplify test setup and assertions.

Testing Strategy

• Unit Tests: Added comprehensive unit tests in WALConfirmOffsetCalculatorTest to validate all critical paths and edge cases.
• Concurrency Tests: Simulated concurrent operations to ensure thread safety and correctness under load.
• Edge Case Validation: Tested with extreme values (e.g., Long.MAX_VALUE, zero) to ensure robustness.

[CLAassistant]

All committers have signed the CLA.

[godsboy404]

Is this okay? or just simply let me know... I'm kinda newbie to contribute to such a massive project:)

[daniel-y]

@godsboy404 Thanks for your contribution. Will review it soon.