Demonstrating constructing parent/child relationships via TestStack Dossier.

TestStack.Dossier.Parent.Child.cs

using System;
using System.Collections.Generic;
using System.Linq;
using Shouldly;
using TestStack.Dossier;
using TestStack.Dossier.Lists;
using Xunit;

namespace Dossier
{
    public class BuilderTest
    {
        [Fact]
        public void TestBuilder()
        {
            var placements = PlacementBuilder
                .CreateListOfSize(10)
                .All().WithPlacementReference("sdfsdf")
                .BuildList();

            OrderBuilder b = OrderBuilder.Default;
            Order order = b
                .WithOrderReference("order")
                .WithPlacements(10, pb => pb.WithPlacementReference("sdfsdf"));
            
            order.OrderReference.ShouldBe("order");
            order.Placements.Count.ShouldBe(10);
        }
    }
    
    public class Order
    {
        public string OrderReference { get; set; }

        public List<Placement> Placements { get; }

        public Order()
        {
            Placements = new List<Placement>();
        }

        public void AddPlacement(Placement placement)
        {
            Placements.Add(placement);
        }
    }

    public class Placement
    {
        public string PlacementReference { get; set; }
    }

    public class OrderBuilder : TestDataBuilder<Order, OrderBuilder>
    {
        public static OrderBuilder Default => new OrderBuilder();
        
        public OrderBuilder WithOrderReference(string value) => Set(x => x.OrderReference, value);

        public OrderBuilder WithPlacements(int count, Func<PlacementBuilder, PlacementBuilder> modifier = null) 
            => Set(x => x.Placements, PlacementBuilder.CreateListOfSize(count).All().With(modifier).BuildList().ToList());

        protected override Order BuildObject()
        {
            var o = new Order
            {
                OrderReference = Get(x => x.OrderReference)
            };

            o.Placements.AddRange(Get(x => x.Placements));
            return o;
        }
    }
    
    public class PlacementBuilder : TestDataBuilder<Placement, PlacementBuilder>
    {
        public static PlacementBuilder Default => new PlacementBuilder();
        
        public virtual PlacementBuilder WithPlacementReference(string value) => Set(x => x.PlacementReference, value);
    }
}