public async Task Given_SingleEntity_Should_TimeTravel()
{
var context = TestHelper.GetNewDbContext();
var appleId = Guid.Parse("00000002-8803-4263-ada6-cd12a33d8872");
context.Apples.Add(new Apple {
Id = appleId, FruitStatus = FruitStatus.Ripe
});
await context.SaveChangesAsync();
var ripeAppleTime = TestHelper.UtcNow;
context = TestHelper.GetNewDbContext();
var ripeApple = await context.Apples.SingleAsync(a => a.Id == appleId);
ripeApple.FruitStatus = FruitStatus.Rotten;
await context.SaveChangesAsync();
context = TestHelper.GetNewDbContext();
var currentApple = await context.Apples.AsNoTracking().SingleAsync(a => a.Id == appleId);
currentApple.FruitStatus.Should().Be(FruitStatus.Rotten);
using (TemporalQuery.AsOf(ripeAppleTime))
{
var timeTravelApple = await context.Apples.AsNoTracking().SingleAsync(a => a.Id == appleId);
timeTravelApple.FruitStatus.Should().Be(FruitStatus.Ripe);
}
}
private static async Task AssertWormlessFruitStatusAtTime(
FruitStatus expectedFruitStatus,
DateTime appleTime,
Guid appleId)
{
using (TemporalQuery.AsOf(appleTime))
{
var apple = await GetApple(appleId);
apple
.Should()
.BeEquivalentTo(new { FruitStatus = expectedFruitStatus, Worms = Array.Empty <Worm>() },
options => options.ExcludingMissingMembers());
}
}
public async Task Given_IncludedCollection_Should_TimeTravelIncludedCollection()
{
var context = TestHelper.GetNewDbContext();
var appleId = Guid.Parse("00000003-8803-4263-ada6-cd12a33d8872");
var apple = new Apple {
Id = appleId, FruitStatus = FruitStatus.Rotten
};
apple.AddWorm("Gav");
context.Apples.Add(apple);
await context.SaveChangesAsync();
var rottenAppleTime = TestHelper.UtcNow;
context = TestHelper.GetNewDbContext();
apple = await context.Apples.SingleAsync(a => a.Id == appleId);
apple.AddWorm("G-Dog");
apple.AddWorm("Gavin' A Laugh");
await context.SaveChangesAsync();
context = TestHelper.GetNewDbContext();
var currentApple = await context.Apples
.Include(a => a.Worms)
.SingleAsync(a => a.Id == appleId);
currentApple.Worms.Count.Should().Be(3);
using (TemporalQuery.AsOf(rottenAppleTime))
{
// Let's use the same context for time travel
var timeTravelApple = await context.Apples
.Include(a => a.Worms)
// All temporal queries must be .AsNoTracking()
.AsNoTracking()
.SingleAsync(a => a.Id == appleId);
timeTravelApple.Worms.Count.Should().Be(1);
}
}
private static async Task AssertWormsNavigationPropertyAtRottenAppleTime(DateTime rottenAppleTime, Guid appleId)
{
using (TemporalQuery.AsOf(rottenAppleTime))
{
using var localScope = ServiceProvider.CreateScope();
var context = localScope.ServiceProvider.GetService <ApplicationDbContext>();
var rottenAppleWorms = await context.Apples
.Where(a => a.Id == appleId)
.SelectMany(a => a.Worms)
.Include(worm => worm.Weapons)
.AsNoTracking().ToListAsync();
rottenAppleWorms
.Should()
.BeEquivalentTo(new[] { new { Name = "Moe", Weapons = new[] { new { Name = "Bazooka" } } } },
options => options.ExcludingMissingMembers());
}
}
public async Task TemporalQuery_Should_AllowAllTemporalEntitiesToTimeTravel()
{
var(appleId, unripeAppleTime, ripeAppleTime, rottenAppleTime) = await SimulateLifecycleOfMyApple();
// Validate current state of my apple
var currentApple = await GetApple(appleId);
currentApple
.Should()
.BeEquivalentTo(
new
{
FruitStatus = FruitStatus.Fuzzy,
Worms = new object[]
{
new
{
Name = "Hairy",
Weapons = new[]
{
new { Name = "Holy Hand Grenade" }, new { Name = "Super Banana Bomb" }
},
FriendsNames = new[] { "Joan", "Starr", "Curly" }
},
new { Name = "Curly" },
new
{
Name = "Moe",
Weapons = new[] { new { Name = "Bazooka Pie" } },
FriendsNames = new[] { "John" }
}
}
}, options => options.ExcludingMissingMembers());
// Query the state of my apple a prior "system time" when the apple was rotten
using (TemporalQuery.AsOf(rottenAppleTime))
{
var rottenApple = await GetApple(appleId);
rottenApple
.Should()
.BeEquivalentTo(
new
{
FruitStatus = FruitStatus.Rotten,
Worms = new object[]
{
new
{
Name = "Moe",
Weapons = new[] { new { Name = "Bazooka" } },
FriendsNames = new[] { "John", "Ringo" }
}
}
},
options => options.ExcludingMissingMembers());
}
await Task.WhenAll(new[]
{
AssertWormlessFruitStatusAtTime(FruitStatus.Ripe, ripeAppleTime, appleId),
AssertWormlessFruitStatusAtTime(FruitStatus.Unripe, unripeAppleTime, appleId),
AssertWormsNavigationPropertyAtRottenAppleTime(rottenAppleTime, appleId)
});
}