[DO NOT MERGE] fix: return documents in insertion order for queries without ORDER BY#73
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Queries without ORDER BY now return documents in insertion order, matching real Cosmos DB behavior. Previously documents were returned in hash-map order due to ConcurrentDictionary enumeration. Added insertion-order tracking list to InMemoryContainer that maintains document position across create, replace, upsert, and delete operations. GetAllItemsForPartition() now iterates this ordered list instead of the dictionary directly. Fixes #72 Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
Comprehensive edge case tests covering: - Large batch (55 docs) insertion order - Multi-partition interleaved insertion order - Repeated replaces preserving position - Mixed operations sequence (create/delete/replace/upsert) - SELECT projections maintaining order - WHERE filter preserving relative order - TOP and OFFSET/LIMIT pagination order - Empty container and single document edge cases - Delete all + recreate ordering - Upsert-only creates ordering - DISTINCT VALUE preserving first occurrence order - COUNT and SUM aggregates not crashing - Cross-partition vs single-partition order - Rapid sequential creates order - ORDER BY overriding insertion order - Range filter preserving relative order - Multiple non-consecutive deletes preserving remaining order Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
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Summary
Fixes #72 — Queries without
ORDER BYnow return documents in insertion order, matching real Cosmos DB behavior.Problem
InMemoryContainer._itemsis aConcurrentDictionarywhich does not guarantee enumeration order.GetAllItemsForPartition()iterated this dictionary directly, causing documents to be returned in hash-bucket order rather than insertion order.Solution
Added an
_insertionOrderlist (List<(string Id, string PartitionKey)>) protected by a lock that tracks the order in which documents are inserted. Key behavioral rules:GetAllItemsForPartition()now snapshots this ordered list and iterates it instead of the dictionary, ensuring queries withoutORDER BYreturn documents in insertion order.All mutation sites are updated: typed and stream variants of Create/Upsert/Delete/Replace, bulk delete by partition key, TTL eviction, state import/export, snapshot restore, and point-in-time restore.
Behavioral Source
Observed behavior on the Windows Cosmos DB Emulator (priority 6): documents returned by queries without ORDER BY are in insertion order.
Testing
Version
Bumped 4.0.17 → 4.0.18