test(spill): add unit tests and integration tests for spill-to-disk

[dalingmeng]

Purpose

Linked issue: #149
add unit tests and integration tests for spill-to-disk

Tests

WriteInteTest.TestPkSpillable.*
KeyValueFileStoreWriteTest.TestSpill.*
MergeTreeWriterTest.TestSpill.*
WriteBufferTest.TestSpill.*
SpillReaderWriterTest

API and Format

Documentation

Generative AI tooling

Claude opus 4.6

[Copilot]

Pull request overview

Note

Copilot was unable to run its full agentic suite in this review.

Adds comprehensive unit/integration coverage for spill-to-disk behavior (incl. quota exhaustion, cleanup, dedup, intermediate merge, and IO error handling), linked to issue #149.

Changes:

• Adds new spill-focused integration tests to validate correctness, cleanup, and failure fallbacks.
• Adds unit tests around spill file quotas, reader ordering, merge behavior, and resource cleanup.
• Refactors repeated commit/scan logic in integration tests into helper methods.

Reviewed changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 6 comments.

Show a summary per file

File	Description
test/inte/write_inte_test.cpp	Adds PK spill integration tests + introduces Commit/Scan helper utilities to reduce duplication.
src/paimon/core/operation/key_value_file_store_write_test.cpp	Adds spill tests for disk-quota fallback and multi-round dedup semantics.
src/paimon/core/mergetree/write_buffer_test.cpp	Adds extensive WriteBuffer spill/quota/reader/cleanup test coverage.
src/paimon/core/mergetree/spill_reader_writer_test.cpp	Adds tests for writer Close idempotency and schema mismatch error cases.
src/paimon/core/mergetree/merge_tree_writer_test.cpp	Adds MergeTreeWriter spill tests: dedup, intermediate merge bounds, quota fallback, cleanup.

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[lucasfang]

+1

[lxy-9602]

+1