changhuixu

[TestMethod]
public void TestWithNullLogger()
{
    var svc = new CalculationService(new NullLogger<CalculationService>());
    var result = svc.AddTwoPositiveNumbers(1, 2);
    Assert.AreEqual(3, result);
}

changhuixu

[TestMethod]
public void TestWithConsoleLogger()
{
     using var loggerFactory = LoggerFactory.Create(builder => builder.AddConsole());
     var logger = loggerFactory.CreateLogger<CalculationService>();
     var svc = new CalculationService(logger);
     var result = svc.AddTwoPositiveNumbers(1, 2);
     Assert.AreEqual(3, result);

     // If you are using .NET Core 2.1.

changhuixu

[TestMethod]
public void TestWithDependencyInjectionLogger()
{
    var services = new ServiceCollection()
        .AddLogging(config => config.AddConsole())      // can add any logger(s)
        .BuildServiceProvider();
    using (var loggerFactory = services.GetRequiredService<ILoggerFactory>())
    {
        var svc = new CalculationService(loggerFactory.CreateLogger<CalculationService>());
        var result = svc.AddTwoPositiveNumbers(1, 2);

changhuixu

[TestMethod]
public void TestWithMockLogger()
{
    var loggerMock = new Mock<ILogger<CalculationService>>();
    var svc = new CalculationService(loggerMock.Object);

    var result = svc.AddTwoPositiveNumbers(1, 2);
    Assert.AreEqual(3, result);
    loggerMock.Verify(
        m => m.Log(

changhuixu

public class BankAccount
{
    public int Id { get; set; }
    public decimal Balance { get; set; }

    public void Credit(decimal amount)
    {
        Console.WriteLine($"Balance before credit:{Balance,5}");
        Console.WriteLine($"Amount to add        :{amount,5}");
        Balance += amount;

changhuixu

var threads = new Thread[2];
threads[0] = new Thread(async () =>
{
    using (var dbContext = new MyDbContext())
    {
        var account = await dbContext.BankAccounts.FindAsync(1);
        account.Credit(100);
        await dbContext.SaveChangesAsync();
    }
});

changhuixu

internal class BankAccountEntityTypeConfigurationSqlite : IEntityTypeConfiguration<BankAccount>
{
    public void Configure(EntityTypeBuilder<BankAccount> builder)
    {
        builder.ToTable("BankAccounts");
        builder.HasKey(x => x.Id);
        builder.Property(x => x.Id).HasColumnName("Id").ValueGeneratedOnAdd();
        builder.Property(x => x.Balance).HasColumnName("Balance").HasConversion<double>()
               .IsConcurrencyToken();
    }

changhuixu

info: Microsoft.EntityFrameworkCore.Database.Command[20101]
      Executed DbCommand (1ms) [Parameters=[@p1='?', @p0='?', @p2='?'], CommandType='Text', CommandTimeout='30']
      UPDATE "BankAccounts" SET "Balance" = @p0
      WHERE "Id" = @p1 AND "Balance" = @p2;
      SELECT changes();

changhuixu

using (var dbContext = new MyDbContext())
{
    var account = await dbContext.BankAccounts.FindAsync(1);
    account.Credit(100);
    try
    {
        await dbContext.SaveChangesAsync();  // Attempt to save changes to the database
    }
    catch (DbUpdateConcurrencyException e)
    {

changhuixu

internal class BankAccountEntityTypeConfigurationSqlite : IEntityTypeConfiguration<BankAccount>
{
    public void Configure(EntityTypeBuilder<BankAccount> builder)
    {
        builder.ToTable("BankAccounts");
        builder.HasKey(x => x.Id);
        builder.Property(x => x.Id).HasColumnName("Id").ValueGeneratedOnAdd();
        builder.Property(x => x.Balance).HasColumnName("Balance").HasConversion<double>();
        builder.Property(x => x.Timestamp).HasColumnName("Timestamp")
            .HasColumnType("BLOB")