Dominic Burford - Professional Profile

Wikipedia:

Defensive programming is a form of defensive design intended to ensure the continuing function of a piece of software under unforeseen circumstances. Defensive programming practices are often used where high availability, safety or security is needed.

Assert()

SqlConnection connection = new SqlConnection("myDatabaseConnectionString");
connection.Open(); //what if this line of code fails!!
SqlCommand cmd = new SqlCommand("myStoredProcedure", connection)

SqlDataReader reader = cmd.ExecuteReader();
string firstName= reader["firstName"]; //what if there was no data or the value for firstname is null!!

MyMoneyClass money; //declared but not initialised
decimal funds = money.GetFunds(); //this will cause an error as it has not been initialised!!

<add key="requireApiKey" value="true"/>

<add key="allowOverrideExistingPackageOnPush" value="false"/>

-verbosity detailed -source "\\network\share\nuget" -packagesdirectory "Solution\Main\packages"

try / catch

public class MyDataClass: BaseData, IMyInterface
{
	// implement data methods here
}

public class MyUnitTestDataClass: IMyInterface
{
	// implement data methods here
}

public interface IMyInterface
{
    List<Mileage> GetPreviousMileages(int driverId);
    List<Driver> GetDriverVehicles(int driverId);
}

public class MyBusinessService
{
    private readonly IMyInterface _data;

    /// <summary>
    /// If no data class is passed to the constructor then use the default data class.
    /// </summary>
    public MyBusinessService()
    {
        this._data = new MyDataClass();
    }

    /// <summary>
    /// Allow unit testing fixtures to implement their own version of the data class
    /// which can be injected via the constructor.
    /// </summary>
    /// <param name="data"></param>
    public MyBusinessService(IMyInterface data)
    {
        this._data = data;
    }
}

[TestMethod]
public void MyTestMethods()
{
    //Act
    MyBusinessService service = new MyBusinessService(new MyUnitTestDataClass()); //inject your unit test class here
            
    //Arrange
    var result = service.GetPreviousMileages(123);

    //Assert
    Assert.IsNotNull(result);
    Assert.IsTrue(result.Any());
}

//the client application serialises the date
string jsonDate = JavaScriptSerializer().Serialize(DateTime.Now);

//the receiving application attempts to de-serialise the date
DateTime dt = new JavaScriptSerializer().Deserialize<DateTime>(jsonDate); //this throws an exception!

/Date(1484904895490)/

var isoConvert = new IsoDateTimeConverter { DateTimeFormat = "yyyy-MM-dd HH:mm:ss" };
DateTime dt = JsonConvert.SerializeObject(jsonDate, isoConvert);

[TestMethod]
public void ClearDeadLetterQueue()
{
    string deadLetterQueueName = "myQueue/$DeadLetterQueue";
    QueueClient client = QueueClient.CreateFromConnectionString("connectionString",
            deadLetterQueueName, ReceiveMode.PeekLock);
     while (client.Receive() != null)
    {
        var receivedMessage = client.Receive();
	//do something with the message here
        receivedMessage?.Complete();
    }
}

using System;
using System.Collections.Generic;
using System.Threading.Tasks;
using Microsoft.ServiceBus.Messaging;

public static void Run(BrokeredMessage message, TraceWriter log)
{
    log.Info($"C# ServiceBus queue trigger function processed message: {message.MessageId}");

    try
    {
        if (message != null)
        {
            //do something with the message here

            log.Info("Completing message.");
            message.Complete();
        }
    }
    catch (Exception ex)
    {
        message.Abandon();
        log.Info($"Exception occurred: {ex.Message}");
    }
}