dotnet-dynamic-query/PoweredSoft.DynamicQuery.Test/AggregateInterceptorTests.cs

using PoweredSoft.DynamicQuery.Core;
using PoweredSoft.DynamicQuery.Test.Mock;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using Xunit;

namespace PoweredSoft.DynamicQuery.Test
{
    public class AggregateInterceptorTests
    {
        private class MockAggregateInterceptor : IAggregateInterceptor
        {
            public IAggregate InterceptAggregate(IAggregate aggregate) => new Aggregate
            {
                Path = "Item.Price",
                Type = AggregateType.Avg
            };
        }

        [Fact]
        public void Simple()
        {
            MockContextFactory.SeedAndTestContextFor("AggregatorInterceptorTests_Simple", TestSeeders.SimpleSeedScenario, ctx =>
            {
                var expected = ctx.OrderItems.GroupBy(t => true).Select(t => new
                {
                    PriceAtTheTime = t.Average(t2 => t2.Item.Price)
                }).First();

                var criteria = new QueryCriteria();
                criteria.Aggregates.Add(new Aggregate
                {
                    Type = AggregateType.Avg,
                    Path = "ItemPrice"
                });
                var queryHandler = new QueryHandler();
                queryHandler.AddInterceptor(new MockAggregateInterceptor());
                var result = queryHandler.Execute(ctx.OrderItems, criteria);
                Assert.Equal(expected.PriceAtTheTime, result.Aggregates.First().Value);
            });
        }
    }
}