Update codebase

src/AdditionalPatterns/EventAggregator/StoreManagement/Components/EventAggregator.cs

@@ -66,7 +66,7 @@ public IDisposable Subscribe(ICustomObserver<IEvent> observer) =>
     public IDisposable Subscribe<T>(ICustomObserver<T> newObserver)
         where T : IEvent
     {
-        if (!_typedObservers.TryGetValue(typeof(T), out List<IObserver<IEvent>> observers))
+        if (!_typedObservers.TryGetValue(typeof(T), out var observers))
         {
             observers = new List<IObserver<IEvent>>();
             _typedObservers[typeof(T)] = observers;

src/AdditionalPatterns/Repository/OrderManagement/Infrastructure/OrderManagementContext.cs

@@ -5,8 +5,8 @@ namespace OrderManagement.Infrastructure;
 
 public class OrderManagementContext : DbContext
 {
-    public DbSet<Customer> Customers { get; set; }
-    public DbSet<Order> Orders { get; set; }
+    public DbSet<Customer> Customers => Set<Customer>();
+    public DbSet<Order> Orders => Set<Order>();
 
     protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder) =>
         optionsBuilder.UseSqlite("Data Source=storage.db");

src/AdditionalPatterns/ServiceLocator/OrderProcessing/IServiceLocator.cs

@@ -2,8 +2,8 @@
 
 public interface IServiceLocator
 {
-    void AddService<T>(T service);
-    void AddService<T>(string serviceName, T service);
-    T GetService<T>();
-    object GetService<T>(string serviceName);
+    void AddService<T>(T service) where T : notnull;
+    void AddService<T>(string serviceName, T service) where T : notnull;
+    T GetService<T>() where T : notnull;
+    object GetService<T>(string serviceName) where T : notnull;
 }

src/AdditionalPatterns/ServiceLocator/OrderProcessing/ServiceLocator.cs

@@ -25,16 +25,16 @@ public ServiceLocator()
         };
     }
 
-    public void AddService<T>(T service) =>
+    public void AddService<T>(T service) where T : notnull =>
         _services.Add(typeof(T).Name, service);
 
-    public void AddService<T>(string serviceName, T service) =>
+    public void AddService<T>(string serviceName, T service) where T : notnull =>
         _services.Add(serviceName, service);
 
-    public T GetService<T>() =>
+    public T GetService<T>() where T : notnull =>
         (T)_services[typeof(T).Name];
 
-    public object GetService<T>(string serviceName) =>
+    public object GetService<T>(string serviceName) where T : notnull =>
         (T)_services[serviceName];
 
     /*public void AddService(string serviceName)

src/AdditionalPatterns/Specification/ProductSpecification/Domain/Entity.cs

@@ -26,7 +26,7 @@ protected Entity()
 
     public static bool operator !=(Entity a, Entity b) => !(a == b);
 
-    public override bool Equals(object obj)
+    public override bool Equals(object? obj)
     {
         if (obj is not Entity other)
         {

src/AdditionalPatterns/UnitOfWork/UnitOfWorkLibrary/Example1/Infrastructure/OrderManagementContext1.cs

@@ -5,8 +5,8 @@ namespace UnitOfWorkLibrary.Example1.Infrastructure;
 
 public class OrderManagementContext1 : DbContext
 {
-    public DbSet<Customer> Customers { get; set; }
-    public DbSet<Order> Orders { get; set; }
+    public DbSet<Customer> Customers => Set<Customer>();
+    public DbSet<Order> Orders => Set<Order>();
 
     protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder) =>
         optionsBuilder.UseSqlite("Data Source=storage1.db");

src/AdditionalPatterns/UnitOfWork/UnitOfWorkLibrary/Example1/Infrastructure/Repositories/Repository1.cs

@@ -37,8 +37,11 @@ public virtual IEnumerable<T> Get(Expression<Func<T, bool>> predicate) =>
             .Where(predicate)
             .ToList();
 
-    public virtual T GetById(int id) =>
-        _context.Find<T>(id);
+    public virtual T GetById(int id)
+    {
+        var entity = _context.Find<T>(id);
+        return entity ?? throw new ArgumentException($"Entity with {id} doesn't exists");
+    }
 
     public virtual void Delete(T entity) =>
         _context.Remove(entity);

src/AdditionalPatterns/UnitOfWork/UnitOfWorkLibrary/Example2/Infrastructure/OrderManagementContext2.cs

@@ -5,8 +5,8 @@ namespace UnitOfWorkLibrary.Example2.Infrastructure;
 
 public class OrderManagementContext2 : DbContext, IUnitOfWork2
 {
-    public DbSet<Customer> Customers { get; set; }
-    public DbSet<Order> Orders { get; set; }
+    public DbSet<Customer> Customers => Set<Customer>();
+    public DbSet<Order> Orders => Set<Order>();
 
     public async Task<bool> SaveChangesAndDispatchDomainEventsAsync(CancellationToken cancellationToken = default)
     {

src/BehavioralPatterns/Mediator/MediatorLibrary/AirTrafficControlExample/Components/Common/Aircraft.cs

@@ -38,14 +38,13 @@ public int Altitude
 
     public void Climb(int heightToClimb) => Altitude += heightToClimb;
 
-    public override bool Equals(object obj)
+    public override bool Equals(object? obj)
     {
-        if (obj.GetType() != GetType())
+        if (obj is not Aircraft incoming)
         {
             return false;
         }
 
-        var incoming = (Aircraft)obj;
         return CallSign.Equals(incoming.CallSign, StringComparison.Ordinal);
     }
 

src/BehavioralPatterns/Observer/ObserverLibrary/StockExample/Examples/EventAndDelegate/Subscribers/GoogleSubscriber.cs

@@ -6,7 +6,7 @@ public class GoogleSubscriber
 {
     public GoogleSubscriber(StockTicker stockTicker)
     {
-        stockTicker.StockChange += CheckFilterWhenStockChanged;
+        stockTicker.StockChange += CheckFilterWhenStockChanged!;
     }
 
     private void CheckFilterWhenStockChanged(object sender, StockChangeEventArgs e)

src/BehavioralPatterns/Observer/ObserverLibrary/StockExample/Examples/EventAndDelegate/Subscribers/MicrosoftSubscriber.cs

@@ -8,7 +8,7 @@ public class MicrosoftSubscriber
 
     public MicrosoftSubscriber(StockTicker stockTicker)
     {
-        stockTicker.StockChange += CheckFilterWhenStockChanged;
+        stockTicker.StockChange += CheckFilterWhenStockChanged!;
     }
 
     private void CheckFilterWhenStockChanged(object sender, StockChangeEventArgs e)

src/BehavioralPatterns/State/StateLibrary/SteakCookingExample/States/Common/Doneness.cs

@@ -3,7 +3,7 @@
 /// <summary>
 /// Doneness is a gauge of how thoroughly cooked a cut of meat is based on
 /// its color, juiciness, and internal temperature when cooked.
-/// In this example we use celsisus degree as a unit of temperature measurment.
+/// In this example we use celsisus degree as a unit of temperature measurement.
 /// </summary>
 public abstract class Doneness
 {
@@ -15,14 +15,15 @@ public abstract class Doneness
     protected int _temperatureChangeStep;
 
     protected Doneness(Doneness state)
-        : this()
     {
         _steak = state.Steak;
         _currentTemperature = state.CurrentTemperature;
+        _temperatureChangeStep = 1;
     }
 
-    protected Doneness()
+    protected Doneness(Steak steak)
     {
+        _steak = steak;
         _temperatureChangeStep = 1;
     }
 

src/BehavioralPatterns/State/StateLibrary/SteakCookingExample/States/Uncooked.cs

@@ -5,10 +5,9 @@ namespace StateLibrary.SteakCookingExample.States;
 public class Uncooked : Doneness
 {
     public Uncooked(Steak steak, double currentTemperature)
+        : base(steak)
     {
-        _steak = steak;
         _currentTemperature = currentTemperature;
-
         _lowerTemperature = 0;
         _upperTemperature = 49;
         _isSafeToEat = false;

src/CreationalPatterns/Prototype/PrototypeLibrary/DeepCloneExample/Extensions/SystemExtension.cs

@@ -7,6 +7,13 @@ public static class SystemExtension
     public static T DeepClone<T>(this T source)
     {
         var serialized = JsonConvert.SerializeObject(source);
-        return JsonConvert.DeserializeObject<T>(serialized);
+        var clonedObject = JsonConvert.DeserializeObject<T>(serialized);
+
+        if (clonedObject == null)
+        {
+            throw new JsonException("The source can't be serialized and deserialized successfully.");
+        }
+
+        return clonedObject;
     }
 }

src/StructuralPatterns/Flyweight/FlyweightLibrary/DotNetStringExample/DotNetStringExecutor.cs

@@ -14,10 +14,10 @@ public static void Execute()
         string s3 = s1;
 
         Console.WriteLine("Enter s4: ");
-        string s4 = Console.ReadLine();
+        string s4 = Console.ReadLine()!;
 
         Console.WriteLine("Enter s5: ");
-        string s5 = string.Intern(Console.ReadLine());
+        string s5 = string.Intern(Console.ReadLine()!);
 
         // In this case, s1 and s2 are two separate strings, and hence the output should be false.
         // Surprisingly, the output is true! This is because .NET runtime in order to save space,