public async Task WhenRemovingAChildEntity()
{
var order = new Order("Apple, 1 Infinite Loop, Cupertino");
var product = new Product("MacBook Pro 13", 1749.00m);
order.AddLine(product, 1);
using (var context = new ChangeTrackingContext()) {
context.Orders.Add(order);
await context.SaveChangesAsync();
}
using (var context = new ChangeTrackingContext()) {
var fetchedOrder = await context.Orders.Include(x => x.Lines).FirstAsync(x => x.Id == order.Id);
Assert.NotNull(fetchedOrder);
fetchedOrder.RemoveLine(order.Lines.First()); // this does not work because it bypasses the proxy!
// fetchedOrder.Lines.Remove(fetchedOrder.Lines.First());
Assert.Equal(EntityState.Unchanged, context.ChangeTracker.Entries <Order>().Single().State);
Assert.Equal(EntityState.Deleted, context.ChangeTracker.Entries <OrderLine>().Single().State);
await context.SaveChangesAsync();
}
using (var context = new ChangeTrackingContext()) {
var fetchedOrder = await context.Orders.Include(x => x.Lines).FirstAsync(x => x.Id == order.Id);
Assert.NotNull(fetchedOrder);
Assert.Empty(fetchedOrder.Lines);
// OrderLine is deleted because OrderId is part of the Primary Key
var fetchedOrderLine = await context.Set <OrderLine>().FirstOrDefaultAsync(x => x.OrderId == order.Id);
Assert.Null(fetchedOrderLine);
}
}
public async Task WhenUpdatingAChildEntity()
{
var order = new Order("Apple, 1 Infinite Loop, Cupertino");
var product = new Product("MacBook Pro 13", 1749.00m);
order.AddLine(product, 1);
using (var context = new ChangeTrackingContext()) {
context.Orders.Add(order);
await context.SaveChangesAsync();
}
using (var context = new ChangeTrackingContext()) {
var fetchedOrder = await context.Orders.FindAsync(order.Id);
Assert.NotNull(fetchedOrder);
fetchedOrder.Lines.First().Amount = 10;
Assert.Equal(EntityState.Unchanged, context.ChangeTracker.Entries <Order>().Single().State);
Assert.Equal(EntityState.Modified, context.ChangeTracker.Entries <OrderLine>().Single().State);
// this is weird: LinePrice is not updated in ChangeTracker, however, value is successfully persisted to database afterwards.
Assert.Equal(product.Price, context.ChangeTracker.Entries <OrderLine>().Single().CurrentValues[nameof(OrderLine.LinePrice)]);
await context.SaveChangesAsync();
}
using (var context = new ChangeTrackingContext()) {
var fetchedOrder = await context.Orders.FindAsync(order.Id);
Assert.NotNull(fetchedOrder);
Assert.Equal(product.Price * 10, fetchedOrder.Lines.First().LinePrice);
}
}
public async Task WhenDeletingAnEntity()
{
var order = new Order("Apple, 1 Infinite Loop, Cupertino");
using (var context = new ChangeTrackingContext()) {
context.Orders.Add(order);
await context.SaveChangesAsync();
}
using (var context = new ChangeTrackingContext()) {
var fetchedOrder = await context.Orders.Include(x => x.Lines).SingleAsync(x => x.Id == order.Id);
Assert.NotNull(fetchedOrder);
context.Orders.Remove(fetchedOrder);
Assert.Equal(EntityState.Deleted, context.ChangeTracker.Entries <Order>().Single().State);
}
}
public async Task WhenUpdatingAnEntityWithIdenticalData()
{
var order = new Order("Apple, 1 Infinite Loop, Cupertino");
using (var context = new ChangeTrackingContext()) {
context.Orders.Add(order);
await context.SaveChangesAsync();
}
using (var context = new ChangeTrackingContext()) {
var fetchedOrder = await context.Orders.FindAsync(order.Id);
Assert.NotNull(fetchedOrder);
fetchedOrder.UpdateShippingAddress("Apple, 1 Infinite Loop, Cupertino");
Assert.Equal(EntityState.Unchanged, context.ChangeTracker.Entries <Order>().Single().State);
}
}
public async Task WhenAddingAChildEntity()
{
var order = new Order("Apple, 1 Infinite Loop, Cupertino");
var product = new Product("MacBook Pro 13", 1749.00m);
using (var context = new ChangeTrackingContext()) {
context.Orders.Add(order);
await context.SaveChangesAsync();
}
using (var context = new ChangeTrackingContext()) {
var fetchedOrder = await context.Orders.FindAsync(order.Id);
Assert.NotNull(fetchedOrder);
fetchedOrder.AddLine(product, 1);
Assert.Equal(EntityState.Unchanged, context.ChangeTracker.Entries <Order>().Single().State);
Assert.Equal(EntityState.Added, context.ChangeTracker.Entries <OrderLine>().Single().State);
}
}
public async Task WhenRemovingAChildEntity2()
{
var order = new Order("Apple, 1 Infinite Loop, Cupertino");
var product = new Product("MacBook Pro 13", 1749.00m);
order.AddLine2(product, 1);
using (var context = new ChangeTrackingContext()) {
context.Orders.Add(order);
await context.SaveChangesAsync();
}
using (var context = new ChangeTrackingContext()) {
var fetchedOrder = await context.Orders.Include(x => x.Lines2).FirstAsync(x => x.Id == order.Id);
Assert.NotNull(fetchedOrder);
fetchedOrder.Lines2.Remove(fetchedOrder.Lines2.First());
Assert.Equal(EntityState.Unchanged, context.ChangeTracker.Entries <Order>().Single().State);
Assert.Equal(EntityState.Modified, context.ChangeTracker.Entries <OrderLine2>().Single().State);
// EF would like to set the FK to a null value but the property is not nullable.
await Assert.ThrowsAsync <InvalidOperationException>(() => context.SaveChangesAsync());
}
}