Add AsExpandedProperties IQueryable extension method

[Copilot]

Summary

Adds AsExpandedProperties<TModel>() to QueryableExtensions — an IQueryable<T> extension that auto-injects a SELECT projection containing all EF-mapped columns plus the expression-expanded values of every writable [Projectable] property.

Problem

On a tracking DbContext the existing auto-inject logic is intentionally suppressed (to preserve change-tracking semantics):

// Tracking context — projectable properties are NOT populated:
var user = await context.Users.FirstAsync();
user.ComputedProp; // default(int) — not populated

The fix proposed in the architecture analysis: expose a method that explicitly opts into the auto-inject regardless of tracking mode.

Solution

// Now works on tracking contexts too:
var user = await context.Users.AsExpandedProperties().FirstAsync();
user.ComputedProp; // correctly populated via expression expansion

AsExpandedProperties() delegates to ExpandProjectables(), which uses a fresh ProjectableExpressionReplacer with trackByDefault: false. This forces the select injection before the expression tree is handed to EF Core's query compiler, so the compiler's own tracking guard never triggers.

Read-only projectable properties (those without a setter) are excluded from the injected projection because EF Core's materialiser cannot set them; only writable projectables appear in the generated SELECT.

Recommended usage: call AsExpandedProperties() after Where/OrderBy and before terminal operators (FirstAsync, ToListAsync, etc.):

await context.Users
    .Where(u => u.IsActive)
    .AsExpandedProperties()
    .ToListAsync();

Changes

File	Change
src/.../Extensions/QueryableExtensions.cs	New AsExpandedProperties<TModel>() with XML documentation
tests/.../AsExpandedPropertiesTests.cs	3 functional tests (tracking context, tracking with WHERE, NoTracking context)
tests/.../*.verified.txt × 9	Snapshot files for all 3 tests × 3 TFMs

Snapshots

Tracking context (the new case):

SELECT [e].[Id], [e].[Id] * 3
FROM [Entity] AS [e]

Tracking context with WHERE:

SELECT [e].[Id], [e].[Id] * 3
FROM [Entity] AS [e]
WHERE [e].[Id] > 0

[Copilot]

Pull request overview

Adds an opt-in IQueryable<T> extension (AsExpandedProperties<TModel>()) to force projectable-property select injection even on tracking queries, along with functional test coverage and snapshots to validate the generated SQL.

Changes:

• Add AsExpandedProperties<TModel>() to QueryableExtensions as a user-facing API for explicit expanded-property projection.
• Add functional tests covering tracking query root, tracking + Where, and no-tracking behavior.
• Add Verify snapshots for the new functional tests across net8.0, net9.0, and net10.0.

Reviewed changes

Copilot reviewed 11 out of 11 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
src/EntityFrameworkCore.Projectables/Extensions/QueryableExtensions.cs	Adds AsExpandedProperties<TModel>() with XML docs; currently delegates to ExpandProjectables().
tests/EntityFrameworkCore.Projectables.FunctionalTests/AsExpandedPropertiesTests.cs	New functional tests validating SQL projection injection behavior for tracking and no-tracking queries.
tests/EntityFrameworkCore.Projectables.FunctionalTests/AsExpandedPropertiesTests.TrackingContext_QueryRoot_InjectsWritableProjectableProperties.DotNet8_0.verified.txt	Snapshot for tracking query-root case (net8).
tests/EntityFrameworkCore.Projectables.FunctionalTests/AsExpandedPropertiesTests.TrackingContext_QueryRoot_InjectsWritableProjectableProperties.DotNet9_0.verified.txt	Snapshot for tracking query-root case (net9).
tests/EntityFrameworkCore.Projectables.FunctionalTests/AsExpandedPropertiesTests.TrackingContext_QueryRoot_InjectsWritableProjectableProperties.DotNet10_0.verified.txt	Snapshot for tracking query-root case (net10).
tests/EntityFrameworkCore.Projectables.FunctionalTests/AsExpandedPropertiesTests.TrackingContext_WithWhere_InjectsProjectablePropertiesAfterFilter.DotNet8_0.verified.txt	Snapshot for tracking + Where case (net8).
tests/EntityFrameworkCore.Projectables.FunctionalTests/AsExpandedPropertiesTests.TrackingContext_WithWhere_InjectsProjectablePropertiesAfterFilter.DotNet9_0.verified.txt	Snapshot for tracking + Where case (net9).
tests/EntityFrameworkCore.Projectables.FunctionalTests/AsExpandedPropertiesTests.TrackingContext_WithWhere_InjectsProjectablePropertiesAfterFilter.DotNet10_0.verified.txt	Snapshot for tracking + Where case (net10).
tests/EntityFrameworkCore.Projectables.FunctionalTests/AsExpandedPropertiesTests.NoTrackingContext_QueryRoot_InjectsProjectableProperties.DotNet8_0.verified.txt	Snapshot for no-tracking query-root case (net8).
tests/EntityFrameworkCore.Projectables.FunctionalTests/AsExpandedPropertiesTests.NoTrackingContext_QueryRoot_InjectsProjectableProperties.DotNet9_0.verified.txt	Snapshot for no-tracking query-root case (net9).
tests/EntityFrameworkCore.Projectables.FunctionalTests/AsExpandedPropertiesTests.NoTrackingContext_QueryRoot_InjectsProjectableProperties.DotNet10_0.verified.txt	Snapshot for no-tracking query-root case (net10).