Cosmos: Complex properties Query

[JoasE]

Adds Cosmos Db query pipeline support for complex properties
Part of: #31253
Replace IEntityType and IProperty with ITypeBase and IPropertyBase in appropriate places. Along with a couple of class and variable renames
Adds ComplexProperty binding for StructuralTypeProjectionExpression
Do not translate distinct in TranslateDistinct with projections of child documents, related: #34067
Translate Nullable<>.HasValue to != null and Nullable<>.Value to direct property access
Move structural equality to partial class
Translate complex equality by direct comparison
Use CollectionResultExpression for complex property collections
Add assosiations, query and adhoc tests
list.Contains(complexType) not supported as per: 36468
TypeIs not supported, as per: 31250

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        Fixes #bugnumber

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[Copilot]

Pull request overview

Adds Cosmos DB query pipeline support for complex/structural types (complex properties), expanding translation capabilities and adding Cosmos-specific test coverage to validate expected SQL and failure behaviors.

Changes:

• Generalizes Cosmos projection/binding from entity-only to structural types via StructuralTypeProjectionExpression, adding complex-property binding support.
• Introduces structural equality translation for complex types (including parameter extraction support) and adds a Distinct translation guard when client projection is involved.
• Adds/updates Cosmos functional tests for complex type queries and complex-property association scenarios (projection, equality, set operations, collections, primitive collections), plus a few ad-hoc helpers/fixtures.

Reviewed changes

Copilot reviewed 27 out of 27 changed files in this pull request and generated 6 comments.

Show a summary per file

File	Description
test/EFCore.Specification.Tests/Query/AdHocComplexTypeQueryTestBase.cs	Adjusts ad-hoc complex-type test seeding and exposes context for provider-specific derivations.
test/EFCore.Cosmos.FunctionalTests/Query/NorthwindAggregateOperatorsQueryCosmosTest.cs	Updates Distinct-related baselines and replaces CI skip attribute.
test/EFCore.Cosmos.FunctionalTests/Query/ComplexTypeQueryCosmosTest.cs	New Cosmos-specific complex type query test baselines and translation-failure expectations.
test/EFCore.Cosmos.FunctionalTests/Query/Associations/OwnedNavigations/OwnedNavigationsProjectionCosmosTest.cs	Adds a Distinct-over-owned-associate translation-failure test.
test/EFCore.Cosmos.FunctionalTests/Query/Associations/ComplexProperties/ComplexPropertiesStructuralEqualityCosmosTest.cs	New Cosmos tests validating complex/associate structural equality translation behavior.
test/EFCore.Cosmos.FunctionalTests/Query/Associations/ComplexProperties/ComplexPropertiesSetOperationsCosmosTest.cs	New Cosmos tests for set operations over complex-property association scenarios.
test/EFCore.Cosmos.FunctionalTests/Query/Associations/ComplexProperties/ComplexPropertiesProjectionCosmosTest.cs	Enables previously-skipped projection tests and updates baselines accordingly.
test/EFCore.Cosmos.FunctionalTests/Query/Associations/ComplexProperties/ComplexPropertiesPrimitiveCollectionCosmosTest.cs	New Cosmos tests for primitive-collection operations under complex properties.
test/EFCore.Cosmos.FunctionalTests/Query/Associations/ComplexProperties/ComplexPropertiesMiscellaneousCosmosTest.cs	New Cosmos tests for miscellaneous complex-property predicate/value-type translations.
test/EFCore.Cosmos.FunctionalTests/Query/Associations/ComplexProperties/ComplexPropertiesCollectionCosmosTest.cs	New Cosmos tests for complex-property collection operators (Count/Where/Distinct/Index/etc.).
test/EFCore.Cosmos.FunctionalTests/Query/AdHocCosmosTestHelpers.cs	Adds a helper to configure deterministic int key generation for Cosmos ad-hoc tests.
test/EFCore.Cosmos.FunctionalTests/Query/AdHocComplexTypeQueryCosmosTest.cs	New Cosmos ad-hoc complex-type test with Cosmos SQL baselines and Cosmos-specific initialization.
test/EFCore.Cosmos.FunctionalTests/CosmosComplexTypesTrackingTest.cs	Changes one tracking test to skip sync rather than silently completing, and runs async path.
src/EFCore.Cosmos/Query/Internal/SqlExpressionVisitor.cs	Updates visitor dispatch to the new structural projection expression type.
src/EFCore.Cosmos/Query/Internal/Expressions/StructuralTypeProjectionExpression.cs	Renames/generalizes entity projection to structural projection and adds complex-property binding.
src/EFCore.Cosmos/Query/Internal/Expressions/SelectExpression.cs	Tracks whether client projection is used (for later translation decisions like Distinct).
src/EFCore.Cosmos/Query/Internal/Expressions/ObjectReferenceExpression.cs	Generalizes object references from IEntityType to ITypeBase.
src/EFCore.Cosmos/Query/Internal/Expressions/ObjectArrayAccessExpression.cs	Extends array-access expressions to support complex-property collections.
src/EFCore.Cosmos/Query/Internal/Expressions/ObjectAccessExpression.cs	Extends object-access expressions to support complex properties and structural types.
src/EFCore.Cosmos/Query/Internal/CosmosSqlTranslatingExpressionVisitor.cs	Refactors to partial class and routes equality rewriting to structural-type-aware logic.
src/EFCore.Cosmos/Query/Internal/CosmosSqlTranslatingExpressionVisitor.StructuralEquality.cs	New structural equality implementation for entity/complex comparisons and parameter extraction.
src/EFCore.Cosmos/Query/Internal/CosmosShapedQueryCompilingExpressionVisitor.CosmosProjectionBindingRemovingExpressionVisitorBase.cs	Updates projection binding removal to work with structural projections and new access expressions.
src/EFCore.Cosmos/Query/Internal/CosmosQueryableMethodTranslatingExpressionVisitor.cs	Enables complex-property collection translation paths and prevents Distinct in client-projection scenarios.
src/EFCore.Cosmos/Query/Internal/CosmosQuerySqlGenerator.cs	Updates SQL generator to use the new structural projection expression.
src/EFCore.Cosmos/Query/Internal/CosmosProjectionBindingExpressionVisitor.cs	Marks selects that fall back to client projection, impacting later translation decisions.
src/EFCore.Cosmos/Query/Internal/CosmosAliasManager.cs	Updates alias rewriting for structural object references.
src/EFCore.Cosmos/Extensions/Internal/CosmosShapedQueryExpressionExtensions.cs	Updates projection extraction logic for the renamed structural projection expression.

Comments suppressed due to low confidence (3)

src/EFCore.Cosmos/Query/Internal/Expressions/StructuralTypeProjectionExpression.cs:186

• BindComplexProperty throws UnableToBindMemberToEntityProjection with memberType set to "navigation". This looks like a copy/paste error and will produce a misleading error message for complex properties; use a distinct memberType (e.g. "complexProperty") like the relational structural projection does.
  src/EFCore.Cosmos/Query/Internal/Expressions/StructuralTypeProjectionExpression.cs:287
• UpdateEntityType should only be callable when StructuralType is an IEntityType. As written, it uses derivedType.GetAllBaseTypes().Contains(StructuralType) which mixes ITypeBase with the entity-type hierarchy and can misbehave (or fail to compile, depending on the GetAllBaseTypes() return type). Align this with the relational implementation by first asserting/casting StructuralType to IEntityType and then performing the base-type check against that entity type.
  src/EFCore.Cosmos/Query/Internal/Expressions/StructuralTypeProjectionExpression.cs:337
• ToString() still returns the prefix "EntityProjectionExpression" even though the type was renamed to StructuralTypeProjectionExpression, which makes debugging/logging confusing. Update the string to reflect the new type name.

[roji]

@JoasE thanks for this. I'll hold off reviewing until you resolve the Copilot comments above, just to save on the effort (we can do this in future PRs as well). Feel free to ping me once everything's ready for a human review.

[JoasE]

@roji
I made some changes based on your feedback. I think it's good to take a look at the discussion around CollectionResultExpression before doing a complete review

[roji]

Thanks @JoasE, I gave this a full review and it looks very good. See my comments which are mainly nits and test adjustments - we should be able to merge this soon.

[JoasE]

@roji There is still a couple of comments open on differences with relational my review from 6th of march. Did you see all of them? Can I resolve those?

[Copilot]

Pull request overview

Copilot reviewed 31 out of 31 changed files in this pull request and generated 2 comments.

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[roji]

Answered all comments, I think we're getting really close. When everything is addressed/answered let me know, I'll do a final pass.

[Copilot]

Pull request overview

Copilot reviewed 31 out of 31 changed files in this pull request and generated 4 comments.

Comments suppressed due to low confidence (1)

src/EFCore.Cosmos/Query/Internal/CosmosShapedQueryCompilingExpressionVisitor.CosmosProjectionBindingRemovingExpressionVisitorBase.cs:1

• The code unconditionally casts objectAccessExpression.StructuralProperty.DeclaringType to IEntityType. Since ObjectAccessExpression now supports IComplexProperty as well, DeclaringType can be an IComplexType, making this cast invalid (runtime InvalidCastException). Guard this mapping so it only runs for owned navigations (e.g., when StructuralProperty is INavigation), and skip or handle complex properties explicitly.

// Licensed to the .NET Foundation under one or more agreements.

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[roji]

Thanks @JoasE, LGTM - approved. Let me know if there's anything else you want to do here, otherwise I'll hit merge.

Thanks again for all the patient work here! Not an easy task in a codebase that's unfortunately a bit messy and with quite a bit of legacy designs.

[roji]

Looks OK to me, especially considering it's all internal.

@AndriySvyryd PTAL, we can revert this part if you have objections.

[roji]

BTW @JoasE can you drop a line to my email address, listed on my github profile?

[JoasE]

@roji All done on my side! so you can go ahead and merge.
I'm happy we were able to navigate this together to bring this to a success, and thanks for your feedback and time aswell, I learned a lot.