QueryRootTests.cs

using System.ComponentModel.DataAnnotations.Schema;
using EntityFrameworkCore.Projectables.FunctionalTests.Helpers;
using Microsoft.EntityFrameworkCore;

namespace EntityFrameworkCore.Projectables.FunctionalTests
{
    public class QueryRootTests
    {
        public record Entity
        {
            public int Id { get; set; }

            [Projectable(UseMemberBody = nameof(Computed2))]
            public int Computed1 => Id;

            private int Computed2 => Id * 2;

            [Projectable(UseMemberBody = nameof(_ComputedWithBaking))]
            [NotMapped]
            public int ComputedWithBacking { get; set; }

            private int _ComputedWithBaking => Id * 5;
        }

        [Fact]
        public Task UseMemberPropertyQueryRootExpression()
        {
            using var dbContext = new SampleDbContext<Entity>(queryTrackingBehavior: QueryTrackingBehavior.NoTracking);

            var query = dbContext.Set<Entity>();

            return Verifier.Verify(query.ToQueryString());
        }

        [Fact]
        public Task DontUseMemberPropertyQueryRootExpression()
        {
            using var dbContext = new SampleDbContext<Entity>(queryTrackingBehavior: QueryTrackingBehavior.TrackAll);

            var query = dbContext.Set<Entity>();

            return Verifier.Verify(query.ToQueryString());
        }


        [Fact]
        public Task EntityRootSubqueryExpression()
        {
            using var dbContext = new SampleDbContext<Entity>();

            var original = dbContext.Set<Entity>()
                .Where(e => e.ComputedWithBacking == 5);

            var query = original
                .Select(e => new { Item = e, TotalCount = original.Count() });

            return Verifier.Verify(query.ToQueryString());
        }

        [Fact]
        public Task AsTrackingQueryRootExpression()
        {
            using var dbContext = new SampleDbContext<Entity>(queryTrackingBehavior: QueryTrackingBehavior.NoTracking);

            var query = dbContext.Set<Entity>().AsTracking();

            return Verifier.Verify(query.ToQueryString());
        }

        [Fact]
        public Task AsNoTrackingQueryRootExpression()
        {
            using var dbContext = new SampleDbContext<Entity>(queryTrackingBehavior: QueryTrackingBehavior.TrackAll);

            var query = dbContext.Set<Entity>().AsNoTracking();

            return Verifier.Verify(query.ToQueryString());
        }

        // PopulateSettableProperties(false) skips the query root rewrite entirely, so a
        // materialized entity keeps whatever its CLR member returns. Projectables are still
        // expanded wherever a query reads them; see
        // PopulateSettablePropertiesDisabledStillExpandsInProjection below.
        [Fact]
        public Task PopulateSettablePropertiesDisabledQueryRootExpression()
        {
            using var dbContext = new SampleDbContext<Entity>(
                queryTrackingBehavior: QueryTrackingBehavior.NoTracking,
                populateSettableProperties: false);

            var query = dbContext.Set<Entity>();

            return Verifier.Verify(query.ToQueryString());
        }

        [Fact]
        public Task PopulateSettablePropertiesDisabledStillExpandsInProjection()
        {
            using var dbContext = new SampleDbContext<Entity>(
                queryTrackingBehavior: QueryTrackingBehavior.NoTracking,
                populateSettableProperties: false);

            var query = dbContext.Set<Entity>().Select(e => new { e.ComputedWithBacking });

            return Verifier.Verify(query.ToQueryString());
        }
    }
}