fix(query): stop insert_item from silently dropping aggregate query wrappers

[QuantumExplorer]

Problem

Query::insert_item (grovedb-query/src/insert.rs) treats any range-collision as mergeable and rewrites the colliding pair via QueryItem::merge, which can only produce plain key/range variants. When one of the colliding items is an aggregate meta-variant (AggregateCountOnRange / AggregateSumOnRange / AggregateCountAndSumOnRange, wire tags 10–12), the merge silently erases the aggregate wrapper:

let mut query = Query::new_aggregate_count_and_sum_on_range(
    QueryItem::Range(b"a".to_vec()..b"z".to_vec()),
);
query.insert_key(b"extra".to_vec());
// before this fix: query.items == [Range(a..z)] — a plain range query,
// the aggregate semantics silently gone, no error anywhere

The same code path is reachable through Query::merge_with / Query::merge_multiple (they call insert_items) and through AggregateSumQuery::insert_item, which duplicates the logic.

Root cause: collides_with unwraps aggregates transparently via to_range_set(), and QueryItem::merge's output match only constructs plain variants — there is no arm that could ever re-wrap.

Fix

• QueryItem::is_aggregate(): new const helper covering all three meta-variants.
• Query::insert_item + AggregateSumQuery::insert_item: aggregate wrappers are never range-merged. An exact structural duplicate is deduplicated; anything else that overlaps an aggregate item is kept as a separate item. The resulting multi-item shape is then rejected by the existing validate_aggregate_* entry points — both the prove path (operations/proof/generate.rs routes through has_*_anywhere detection) and the get path validate up front — so the semantic conflict surfaces as an explicit validation error instead of a silent wrapper drop. (insert_item is infallible, so keep-and-reject-downstream is the panic-free option.)
• QueryItem::merge / merge_assign: documented the no-aggregates precondition and enforced it with a debug_assert!. The two insert_item guards are the only production callers, so the assert is unreachable from existing code paths.
• Updated the stale insert_item comments (the old ones described a collision-based QueryItem::eq that doesn't exist — PartialEq is derived structural; Ord is the range-set-based comparison) and the insert_all docs.

Audit notes

• intersect / intersect_many_ordered still unwrap aggregates to range sets; in the merge_with/merge_multiple paths they are used only for conditional-subquery bookkeeping, and the aggregate item itself is preserved in items, so has_*_anywhere detection still fires and validation rejects the merged shape. No silent laundering remains.
• Raw iteration (seek_for_iter etc.) delegating aggregates to the inner range is pre-existing and unchanged.

Version-gating consideration

GROVE_V3 is live, but no gating is needed: this changes only in-memory query construction, not proof wire format or state transitions. Aggregate queries are built via the new_aggregate_* constructors and proved/executed as-is; any caller that inserted into one afterwards was already getting silently wrong (non-aggregate) results, so the only behavior change is silent-wrong → explicit validation error.

Tests

Six new unit tests in grovedb-query/src/insert.rs covering: key-into-combined-aggregate (the original repro), range-into-aggregate-count, insert_all into aggregate-sum, aggregate-into-plain-query, identical-aggregate dedupe, and colliding non-identical aggregates — each also asserting the resulting shape is rejected by the matching validator. All previously failing on develop, all passing now. Full suites green: grovedb-query 372, grovedb 2565, merk 711.

🤖 Generated with Claude Code

Summary by CodeRabbit

• Bug Fixes

  • Aggregate query metadata is now preserved during batch insertion.
  • Plain keys and ranges are discarded as expected.
  • Aggregate query items remain separate from overlapping items, preventing incorrect range merging.
  • Exact duplicate items are still removed.
  • Invalid overlapping aggregate queries are now detected and rejected.

• Documentation

  • Clarified query insertion and merging behavior, including ordering and aggregate-item handling.

[coderabbitai]

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ℹ️ Recent review info

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Run ID: 44fe2679-e324-440f-aac7-e4b8a34fc34f

📥 Commits

Reviewing files that changed from the base of the PR and between 0ed25cd and 4112632.

📒 Files selected for processing (1)

• grovedb-query/src/query_item/merge.rs

🚧 Files skipped from review as they are similar to previous changes (1)

• grovedb-query/src/query_item/merge.rs

---

📝 Walkthrough

Walkthrough

Aggregate query insertion now retains aggregate meta-items, avoids merging them with overlapping items, deduplicates exact duplicates, and validates malformed aggregate queries. The shared merge operation rejects aggregate variants.

Changes

Aggregate Query Preservation

Layer / File(s)	Summary
Aggregate detection and merge contract grovedb-query/src/query_item/mod.rs, grovedb-query/src/query_item/merge.rs	QueryItem::is_aggregate identifies aggregate variants. QueryItem::merge and merge_assign reject aggregate items.
Aggregate-aware insertion and validation grovedb-query/src/aggregate_sum_query/insert.rs, grovedb-query/src/insert.rs	Insertion retains aggregate items beside overlapping plain or non-identical aggregate items, deduplicates exact duplicates, and updates ordering documentation. Regression tests cover wrappers, duplicates, overlaps, and malformed aggregate queries.

Estimated code review effort: 3 (Moderate) | ~20 minutes

Mergeability Score: ⚪ Minimal · up to 41126

This change makes aggregate-query conflicts fail explicitly instead of silently dropping aggregate semantics. No actionable merge-blocking risk remains at the current head beyond normal checks and review.

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly describes the main fix: preventing aggregate query wrappers from being silently dropped during insertion.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

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Actionable comments posted: 1

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Inline comments:
In `@grovedb-query/src/query_item/merge.rs`:
- Around line 19-24: Update QueryItem::merge to enforce the non-aggregate
precondition in release builds by replacing the debug-only check with assert!,
or by propagating an appropriate error through the API; ensure merge_assign
retains the same protection when it delegates to merge.

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---

ℹ️ Review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

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Run ID: 2cd99c94-7b34-4d6f-afc7-9c90a59af421

📥 Commits

Reviewing files that changed from the base of the PR and between a2791bb and 0ed25cd.

📒 Files selected for processing (4)

• grovedb-query/src/aggregate_sum_query/insert.rs
• grovedb-query/src/insert.rs
• grovedb-query/src/query_item/merge.rs
• grovedb-query/src/query_item/mod.rs

[codecov]

Codecov Report

❌ Patch coverage is 98.85057% with 1 line in your changes missing coverage. Please review.
✅ Project coverage is 92.22%. Comparing base (a2791bb) to head (4112632).
⚠️ Report is 1 commits behind head on develop.

Files with missing lines	Patch %	Lines
grovedb-query/src/aggregate_sum_query/insert.rs	75.00%	1 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff             @@
##           develop     #796      +/-   ##
===========================================
+ Coverage    92.21%   92.22%   +0.01%     
===========================================
  Files          257      257              
  Lines        78176    78261      +85     
===========================================
+ Hits         72091    72179      +88     
+ Misses        6085     6082       -3     

Components	Coverage Δ
grovedb-core	90.40% <ø> (ø)
merk	93.13% <ø> (ø)
storage	87.00% <ø> (ø)
commitment-tree	96.05% <ø> (ø)
mmr	96.79% <ø> (ø)
bulk-append-tree	89.82% <ø> (ø)
element	97.95% <ø> (ø)

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