Cosmos: Extra clauses are removed from the query when extracting hierarchical partition key values

[ajcvickers]

LINQ:

var sessions = await context.Set<UserSession>()
    .Where(
        e => e.Username.Contains("a")
             && e.TenantId == tenantId
             && e.UserId == userId
             && e.SessionId == sessionId)
    .ToListAsync();

Log:

info: 6/11/2024 09:52:53.942 CosmosEventId.ExecutingSqlQuery[30100] (Microsoft.EntityFrameworkCore.Database.Command) 
      Executing SQL query for container 'AppDbContext' in partition '["Microsoft","99a410d7-e467-4cc5-92de-148f3fc53f4c",7.0]' [Parameters=[]]
      SELECT c
      FROM root c
      WHERE (c["Discriminator"] = "UserSession")

Notice that the Contains clause is missing.

Repro

using (var context = new AppDbContext())
{
    await context.Database.EnsureDeletedAsync();
    await context.Database.EnsureCreatedAsync();

    var tenantId = "Microsoft";
    var sessionId = 7;
    var userId = new Guid("99A410D7-E467-4CC5-92DE-148F3FC53F4C");

    var sessions = await context.Set<UserSession>()
        .Where(
            e => e.Username.Contains("a")
                 && e.TenantId == tenantId
                 && e.UserId == userId
                 && e.SessionId == sessionId)
        .ToListAsync();
}

public class AppDbContext : DbContext
{
    protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
        => optionsBuilder
            .UseCosmos(
                "https://localhost:8081",
                "C2y6yDjf5/R+ob0N8A7Cgv30VRDJIWEHLM+4QDU5DE2nQ9nDuVTqobD4b8mGGyPMbIZnqyMsEcaGQy67XIw/Jw==",
                "EFDatabase")
            .LogTo(Console.WriteLine, LogLevel.Debug)
            .EnableSensitiveDataLogging();

    protected override void OnModelCreating(ModelBuilder modelBuilder)
    {
        modelBuilder
            .Entity<UserSession>()
            .HasPartitionKey(e => new { e.TenantId, e.UserId, e.SessionId });

        modelBuilder
            .Entity<UserSession>()
            .Property(e => e.Id).ValueGeneratedOnAdd();
    }
}

public class UserSession
{
    // Item ID
    public Guid Id { get; set; }

    // Partition Key
    public string TenantId { get; set; } = null!;
    public Guid UserId { get; set; }
    public int SessionId { get; set; }

    // Other members
    public string Username { get; set; } = null!;
}