.NET Разработчик. Страница 4

public class Student
 (int id, string name, IEnumerable<decimal> grades)
{
  public Student(int id, string name) 
   : this(id, name, Enumerable.Empty<decimal>()) { }

  public int Id => id;
  public string Name { get; set; } 
   = name.Trim();
  public decimal GPA => 
   grades.Any() ? grades.Average() : 4.0m;
}

public static T Min<T>(this Span<T> span)
 where T : unmanaged, IMinMaxValue<T>, INumber<T>

var spanAsVectors = 
  MemoryMarshal.Cast<T, Vector<T>>(span);
Span<T> vector = 
  stackalloc T[Vector<T>.Count];
vector.Fill(T.MaxValue);
var min = new Vector<T>(vector);

foreach (var v in spanAsVectors)
  min = Vector.Min(v, min);

var remain = span.Length % Vector<T>.Count;
if (remain > 0)
{
  Span<T> last = 
   stackalloc T[Vector<T>.Count];
  last.Fill(T.MaxValue);
  span[^remain..].CopyTo(last);
  min = Vector.Min(min, new Vector<T>(last));
}

var minVal = T.MaxValue;
for (var i = 0; i < Vector<T>.Count; i++)
  minVal = T.Min(minVal, min[i]);

return minVal;

Method     Mean    Ratio
Linq       67.41us  1.00
For        55.58us  0.82
LinqSIMD   10.78us  0.16

Action act = () => sut.BadMethod();
act.Should().Throw<ArgumentException>();

Action act = () => sut.GoodMethod();
act.Should()
   .NotThrow<NullReferenceException>();

Func<Task> act = () => sut.MethodAsync();

await act.Should()
 .ThrowAsync<ArgumentNullException>();

await act.Should().NotThrowAsync();

public static class EmailStringExtensions
{
  public static AndConstraint<StringAssertions> 
   ContainAtSign(
    this StringAssertions email,
    string because = "",
    params object[] becauseArgs)
  {
    Execute.Assertion
     .BecauseOf(because, becauseArgs)
     .ForCondition(email.Subject.Contains('@'))
     .FailWith(
       "Expected email to contain @{reason}.");

    return new AndConstraint<StringAssertions>(email);
  }
}

string email = "[email protected]";
email.Should()
 .ContainAtSign("because that’s valid email");

var coll = new List<string>
  { "first", "second" };
var coll2 = new List<string>
  { "first", "second" };

coll.Should().NotBeEmpty();
….HaveCount(2);
….Equal(coll2);
….Equal("first", "second");
….BeEquivalentTo(coll2);
….NotBeEquivalentTo(
   new List<string> { "1", "2" });

….OnlyHaveUniqueItems();
….HaveCountGreaterThan(1);
….HaveCountGreaterThanOrEqualTo(2);
….HaveCountLessThanOrEqualTo(5);
….HaveCountLessThan(5);
….NotHaveCount(1);

….StartWith("first");
….StartWith(
   new List<string> { "first" });
….EndWith("second");
….EndWith(
   new List<string> { "first", "second" });
….Contain("first")
  .And.HaveElementAt(1, "first");

….BeEmpty();
….BeNullOrEmpty();
….NotBeNullOrEmpty();
….ContainInOrder(
   new List<string> { "first", "second" });
….NotContainInOrder(
   new List<string> { "1", "2", "3" });

….BeInAscendingOrder();
….BeInDescendingOrder();
….NotBeInAscendingOrder();
….NotBeInDescendingOrder();

DateTime date = new DateTime(2022, 2, 7);

date.Should().Be(7.February(2022).At(0,0));
….BeAfter(6.February(2022).At(23,59));
….BeBefore(8.February(2022).At(0,1));
….BeSameDateAs(7.February(2022));

….NotBe(6.February(2022));
….NotBeAfter(8.February(2022).At(10, 28));
….NotBeBefore(1.January(2022));
….NotBeSameDateAs(27.February(2022));

int numberOfDocuments = 5;
using (new AssertionScope())
{
  numberOfDocuments.Should().Be(6);
  "First Name".Should().Be("Last Name");
}

int number = 5;
number.Should().Be(5);

int number = 6;
number.Should().Be(5, 
 "because that is the correct amount");

sut.Should().BeNull();
….NotBeNull();
….BeOfType<Customer>();
// для сравнения используется Equals
….Be(otherCustomer);

"string".Should().BeNullOrEmpty();
….BeNullOrWhiteSpace();
….NotBeNullOrEmpty();
….NotBeNullOrWhiteSpace();

number.Should().Be(1);
….NotBe(10);
….BePositive();
….BeNegative();
….BeGreaterThanOrEqualTo(88);
….BeGreaterThan(66);
….BeLessThanOrEqualTo(56);
….BeLessThan(61);
….BeInRange(1, 5);
….NotBeInRange(6, 9);

customer.Should()
 .BeEquivalentTo(customerDto);

collectionToTest.Should().Contain("first")
 .And.HaveElementAt(2, "third");

# изменить последний коммит новым сообщением
git commit --amend -m "New message"

# изменить, не меняя сообщения
git commit --amend --no-edit

git reflog

# возврат к предыдущему состоянию
git reset HEAD@{N}

git rebase -i HEAD~N

# изменить сообщение коммита
pick 1234567 Old message
reword 2345678 New message

# изменить порядок коммитов
pick 1234567 First commit
pick 2345678 Second commit
pick 3456789 Third commit

# удалить коммит
pick 1234567 First commit
drop 2345678 Second commit
pick 3456789 Third commit

git config --global alias.ci commit

# использование
git ci -m "Commit message"

git stash

# применить последние сохранённые изменения
git stash apply

# применить выбранные сохранённые изменения
git stash apply stash@{N}

# список всех изменений
git stash list

options.UseSqlServer(
    connectionString,
    x => x.UseHierarchyId());

public HierarchyId NodePath { get; set; }

public class Customer : Entity 
{
  public Order[] Orders { get; private set; }

  public LoyaltyPoints Earned 
   => Orders.Sum(x => x.PointsEarned);

  public LoyaltyPoints Redeemed
   => Orders.Sum(x => x.PointsRedeemed);

  public LoyaltyPoints Points 
   => Earned - Redeemed;
  …
}

public class Customer : Entity 
{
  public LoyaltyPoints Points { get; private set; }

  public void AddPoints(LoyaltyPoints pts)
   => Points += pts; 

  public void RedeemPoints(LoyaltyPoints pts)
  {
    if (Points < 250 || pts > Points)
      throw new Exception();
    Points -= pts;
  }
}

public void SubtractPoints(LoyaltyPoints pts)
 => Points -= points;

public class Customer : Entity 
{
  public LoyaltyPoints Earned { get; private set; }
  public LoyaltyPoints Redeemed { get; private set; }

  public LoyaltyPoints Points 
   => Earned - Redeemed;

  public void IncreasePoints(LoyaltyPoints pts)
   => Earned += pts;

  public void ReducePoints(LoyaltyPoints pts)
   => Earned -= pts;
  …
}

static async Task DoAsync (
 string[] args, CancellationToken ct)
{
  try
  {
    Console.WriteLine("Ожидание…");
    await Task.Delay(10_000, ct);
  }
  catch (OperationCanceledException)
  {
    Console.WriteLine("Операция отменена");
  }
}

using var cts = new CancellationTokenSource();
Console.CancelKeyPress += (sender, e) =>
{
  // Мы остановим процесс вручную
  // с помощью токена отмены
  e.Cancel = true;
  
  // … очистка …

  // Вызываем отмену на токене
  cts.Cancel();
};

await DoAsync(args, cts.Token);

cts.Token.Register(
 () => Console.WriteLine("Отмена…"));

[HttpGet("database")]
[OutputCache(PolicyName = "Expensive")]
public string GetDatabase() 
  => $"Дорогой вызов БД в: {DateTime.Now:hh:mm:ss}";

opt.AddPolicy("Expensive", с =>
  с.Expire(TimeSpan.FromMinutes(1))
   .Tag("tag-expensive"));

opt.AddBasePolicy(с =>
  с.Expire(TimeSpan.FromSeconds(5))
   .Tag("tag-all"));

[HttpDelete("cache/{tag}")]
public async Task DeleteCache(
 IOutputCacheStore cache, string tag) 
  => await cache.EvictByTagAsync(tag, default);

DELETE …/cache/tag-expensive

DELETE …/cache/tag-all

opt.AddPolicy("CacheTenSec", c =>
  c.Expire(TimeSpan.FromSeconds(10))
   .SetVaryByQuery("par1"));

opt.AddPolicy("CacheTenSec", c =>
  c.Expire(TimeSpan.FromSeconds(10))
   .SetVaryByQuery("par1")
   .SetVaryByHeader("X-Client-Id"));

app.MapGet("/etag", async (context) =>
{
  var etag = $"\"{Guid.NewGuid():n}\"";
  context.Response.Headers.ETag = etag;
  await context.Response.WriteAsync("hello");
}).CacheOutput();