Helpers for using EF with SQL Server Temporal Tables

TemporalHelpers.cs

using Microsoft.EntityFrameworkCore;
using Microsoft.EntityFrameworkCore.Metadata.Builders;
public static class TemporalHelpers
{
    public const string PeriodStartFieldName = "PeriodStart";
    public const string PeriodEndFieldName = "PeriodEnd";
    extension<T>(TableBuilder<T> tableBuilder) where T : class
    {
        /// <summary>
        /// Configures the table to be temporal with project defaults.
        /// </summary>
        /// <returns></returns>
        public TableBuilder<T> UseHistoryTable() =>
            tableBuilder.IsTemporal(t =>
            {
                t.HasPeriodStart(PeriodStartFieldName);
                t.HasPeriodEnd(PeriodEndFieldName);
                t.UseHistoryTable($"{tableBuilder.Name}History");
            });
    }

    extension<T>(IQueryable<T> queryable)
    {
        /// <summary>
        /// Maps to a Period<T> object that contains the entity and the period start and end dates.
        /// </summary>
        /// <returns></returns>
        public IQueryable<Period<T>> AsPeriods()
        {
            return queryable.Select(e => new Period<T>(  
                e, 
                EF.Property<DateTime>(e!, PeriodStartFieldName), 
                EF.Property<DateTime>(e!, PeriodEndFieldName)));
        }
    }
}