Add unit tests for ByteArrayBuffer extension functions

[kimsunho2000]

Summary

Add unit tests for ByteArrayBuffer extension functions defined in ByteArrayBuffer.kt.
Closes #119

Changes

• Added ByteArrayBufferTest.kt at core/src/test/kotlin/com/kakao/actionbase/core/codec/

Test Plan

Test	Coverage
putValue and getValue should round trip in ascending order	putValue + getValue roundtrip with ASC ordering
putValue and getValue should round trip in descending order	putValue + getValue roundtrip with DESC ordering
getValue should throw IllegalStateException when value is null	getValue throws IllegalStateException when value is null
getValueOrNull should return null when value is null	getValueOrNull returns null when value is null
hasRemaining should return true when data exists	hasRemaining returns true when data exists
hasRemaining should return false after data is consumed	hasRemaining returns false after data is consumed
hasRemaining should return false for empty buffer	hasRemaining returns false for empty buffer
buffer should create ByteArrayBuffer from ByteArray	buffer() creates valid ByteArrayBuffer from ByteArray
putValue should produce different bytes for asc and desc order	ASC and DESC produce different byte representations
putValue and getValue should maintain order for multiple values	putValue + getValue maintains insertion order for multiple values

How to Test

./gradlew spotlessApply
./gradlew :core:test

[CLAassistant]

All committers have signed the CLA.

[Copilot]

Pull request overview

Adds unit test coverage for ByteArrayBuffer extension functions in core to ensure serialization/deserialization and buffer helpers behave as expected (per #119).

Changes:

• Introduced ByteArrayBufferTest covering putValue, getValue, getValueOrNull, hasRemaining, and ByteArray.buffer().
• Added parameterized coverage across multiple primitive types and ordering modes (ASC/DESC).
• Added assertions for null-handling behavior and ASC vs DESC byte differences.

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[Copilot]

hasRemaining should return true when data exists is currently a vacuous assertion: after ByteArray(BUFFER_SIZE).buffer() and setPosition(0), remaining is still BUFFER_SIZE, so hasRemaining() would be true even if nothing had been written. Consider asserting on a read-buffer created from buffer.toByteArray().buffer() (so length reflects bytes actually written), and/or add a separate case like ByteArray(0).buffer() to verify hasRemaining() is false for an empty buffer.

Suggested change

	buffer.setPosition(0)
	assertTrue(buffer.hasRemaining())
	}
	val writtenBytes = buffer.toByteArray()
	val readBuffer = writtenBytes.buffer()
	assertTrue(readBuffer.hasRemaining())
	}
	@Test
	fun `hasRemaining should return false for empty buffer`() {
	val buffer = ByteArray(0).buffer()
	assertFalse(buffer.hasRemaining())
	}

[zipdoki]

@kimsunho2000
The current assertion is vacuous — since the buffer is backed by ByteArray(BUFFER_SIZE), remaining is always BUFFER_SIZE after setPosition(0) regardless of what was written. Consider switching to buffer.toByteArray().buffer() so the assertion actually reflects bytes written.

Also, if the intent was to cover the empty-buffer case, it might be worth adding a separate test like ByteArray(0).buffer() to explicitly verify hasRemaining() returns false.

[em3s]

@zipdoki Please review when you get a chance.

[zipdoki]

@kimsunho2000
nit: two small consistency things — indent the YAML to match the @ObjectSource style used in EdgeStateMapperTest, and add byte/short to cover the uncovered serialize paths.

[kimsunho2000]

Thanks for the review! @zipdoki I'll update the code and push it soon.

[kimsunho2000]

@zipdoki
I've addressed the review feedback:
commit: 13d391e

• Fixed the vacuous hasRemaining assertion using buffer.toByteArray().buffer()
• Added ByteArray(0).buffer() case to verify hasRemaining() returns false for empty buffer
• Added byte and short types to FIELD_SOURCES
• Fixed YAML indentation to match @ObjectSource style

Also, I added one more test beyond the issue requirements:
commit: 108b480

• putValue and getValue should maintain order for multiple values — verifies that multiple values written sequentially are read back in the correct order, which reflects the actual usage pattern in EdgeIndexRecord.decodeKey.

Please let me know if there's anything else to improve. Thanks!

[zipdoki]

@kimsunho2000
LGTM 👍

Thanks for your continued contributions!