Client Web Socket implementation (#46)

SystemExtensions.NetStandard/Collections/AVLTree.cs

@@ -16,14 +16,14 @@ public sealed class AVLTree<T> : ICollection<T> where T : IComparable<T>
     private class AVLNode<TKey>
     {
         public TKey Value;
-        public AVLNode<TKey> Left;
+        public AVLNode<TKey> Left = default!;
-        public AVLNode<TKey> Right;
+        public AVLNode<TKey> Right = default!;
         public AVLNode(TKey value)
         {
             this.Value = value;
         }
     }
-    AVLNode<T> root;
+    AVLNode<T> root = default!;
     private int count = 0;
     private readonly bool isReadOnly = false;
     #endregion
@@ -98,7 +98,7 @@ public sealed class AVLTree<T> : ICollection<T> where T : IComparable<T>
     /// <param name="value">Value to be deleted.</param>
     public bool Remove(T value)
     {
-        this.root = this.Delete(this.root, value);
+        this.root = this.Delete(this.root, value)!;
         return true;
     }
     /// <summary>
@@ -115,19 +115,19 @@ public sealed class AVLTree<T> : ICollection<T> where T : IComparable<T>
             if (currentNode.Left != null)
             {
                 queue.Enqueue(currentNode.Left);
-                currentNode.Left = null;
+                currentNode.Left = default!;
                 this.count--;
             }
 
             if (currentNode.Right != null)
             {
                 queue.Enqueue(currentNode.Right);
-                currentNode.Right = null;
+                currentNode.Right = default!;
                 this.count--;
             }
         }
 
-        this.root = null;
+        this.root = default!;
         this.count--;
     }
     /// <summary>
@@ -222,9 +222,8 @@ public sealed class AVLTree<T> : ICollection<T> where T : IComparable<T>
 
         return current;
     }
-    private AVLNode<T> Delete(AVLNode<T> current, T target)
+    private AVLNode<T>? Delete(AVLNode<T> current, T target)
     {
-        AVLNode<T> parent;
         if (current == null)
         { return null; }
         else
@@ -232,7 +231,7 @@ public sealed class AVLTree<T> : ICollection<T> where T : IComparable<T>
             //left subtree
             if (target.CompareTo(current.Value) < 0)
             {
-                current.Left = this.Delete(current.Left, target);
+                current.Left = this.Delete(current.Left, target)!;
                 if (this.BalanceFactor(current) == -2)//here
                 {
                     if (this.BalanceFactor(current.Right) <= 0)
@@ -248,7 +247,7 @@ public sealed class AVLTree<T> : ICollection<T> where T : IComparable<T>
             //right subtree
             else if (target.CompareTo(current.Value) > 0)
             {
-                current.Right = this.Delete(current.Right, target);
+                current.Right = this.Delete(current.Right, target)!;
                 if (this.BalanceFactor(current) == 2)
                 {
                     if (this.BalanceFactor(current.Left) >= 0)
@@ -268,14 +267,14 @@ public sealed class AVLTree<T> : ICollection<T> where T : IComparable<T>
                 if (current.Right != null)
                 {
                     //delete its inorder successor
-                    parent = current.Right;
+                    var parent = current.Right;
                     while (parent.Left != null)
                     {
                         parent = parent.Left;
                     }
 
                     current.Value = parent.Value;
-                    current.Right = this.Delete(current.Right, parent.Value);
+                    current.Right = this.Delete(current.Right, parent.Value)!;
                     if (this.BalanceFactor(current) == 2)//rebalancing
                     {
                         if (this.BalanceFactor(current.Left) >= 0)
@@ -294,7 +293,7 @@ public sealed class AVLTree<T> : ICollection<T> where T : IComparable<T>
 
         return current;
     }
-    private AVLNode<T> Find(T target, AVLNode<T> current)
+    private AVLNode<T>? Find(T target, AVLNode<T> current)
     {
         if (current == null)
         {

SystemExtensions.NetStandard/Collections/FibonacciHeap.cs

@@ -8,7 +8,7 @@
 public sealed class FibonacciHeap<T> : IEnumerable<T> where T : IComparable<T>
 {
     #region Fields
-    private FibonacciNode<T> root;
+    private FibonacciNode<T> root = default!;
     private int count;
     #endregion
     #region Properties
@@ -53,8 +53,8 @@ public sealed class FibonacciHeap<T> : IEnumerable<T> where T : IComparable<T>
         {
             Value = value,
             Marked = false,
-            Child = null,
+            Child = default!,
-            Parent = null,
+            Parent = default!,
             Degree = 0
         };
         node.Previous = node.Next = node;
@@ -68,7 +68,7 @@ public sealed class FibonacciHeap<T> : IEnumerable<T> where T : IComparable<T>
     public void Merge(FibonacciHeap<T> otherHeap)
     {
         this.root = this.Merge(this.root, otherHeap.root);
-        otherHeap.root = null;
+        otherHeap.root = default!;
         this.count += otherHeap.count;
     }
     /// <summary>
@@ -80,7 +80,7 @@ public sealed class FibonacciHeap<T> : IEnumerable<T> where T : IComparable<T>
         var currentRoot = this.root;
         if (currentRoot != null)
         {
-            this.root = this.RemoveMinimum(this.root);
+            this.root = this.RemoveMinimum(this.root)!;
             this.count--;
             return currentRoot.Value;
         }
@@ -115,8 +115,8 @@ public sealed class FibonacciHeap<T> : IEnumerable<T> where T : IComparable<T>
     {
         this.count = 0;
         this.Remove(this.root);
-        this.root.Next = this.root.Previous = this.root.Parent = this.root.Child = null;
+        this.root.Next = this.root.Previous = this.root.Parent = this.root.Child = default!;
-        this.root = null;
+        this.root = default!;
     }
     /// <summary>
     /// Return the heap structure as an array. Array is not sorted other than the
@@ -127,7 +127,7 @@ public sealed class FibonacciHeap<T> : IEnumerable<T> where T : IComparable<T>
     {
         if (this.count == 0)
         {
-            return null;
+            return default!;
         }
 
         var array = new T[this.count];
@@ -212,12 +212,12 @@ public sealed class FibonacciHeap<T> : IEnumerable<T> where T : IComparable<T>
                 this.Remove(current.Child);
                 if (current.Parent != null)
                 {
-                    current.Parent.Child = null;
+                    current.Parent.Child = default!;
                 }
 
                 current = current.Next;
             } while (current != node);
-            current.Next = current.Previous = current.Child = current.Parent = null;
+            current.Next = current.Previous = current.Child = current.Parent = default!;
         }
     }
     /// <summary>
@@ -279,7 +279,7 @@ public sealed class FibonacciHeap<T> : IEnumerable<T> where T : IComparable<T>
         do
         {
             current.Marked = false;
-            current.Parent = null;
+            current.Parent = default!;
             current = current.Next;
         } while (current != node);
     }
@@ -288,7 +288,7 @@ public sealed class FibonacciHeap<T> : IEnumerable<T> where T : IComparable<T>
     /// </summary>
     /// <param name="node">Root of the provided tree.</param>
     /// <returns></returns>
-    private FibonacciNode<T> RemoveMinimum(FibonacciNode<T> node)
+    private FibonacciNode<T>? RemoveMinimum(FibonacciNode<T> node)
     {
         this.RemoveParent(node.Child);
         if (node.Next == node)
@@ -318,7 +318,7 @@ public sealed class FibonacciHeap<T> : IEnumerable<T> where T : IComparable<T>
                     break;
                 }
 
-                trees[node.Degree] = null;
+                trees[node.Degree] = default!;
                 if (node.Value.CompareTo(t.Value) < 0)
                 {
                     t.Previous.Next = t.Next;
@@ -379,7 +379,7 @@ public sealed class FibonacciHeap<T> : IEnumerable<T> where T : IComparable<T>
     {
         if (node.Next == node)
         {
-            node.Parent.Child = null;
+            node.Parent.Child = default!;
         }
         else
         {
@@ -413,13 +413,13 @@ public sealed class FibonacciHeap<T> : IEnumerable<T> where T : IComparable<T>
             {
                 root = this.Cut(root, node);
                 var parent = node.Parent;
-                node.Parent = null;
+                node.Parent = default!;
                 while (parent != null && parent.Marked)
                 {
                     root = this.Cut(root, parent);
                     node = parent;
                     parent = node.Parent;
-                    node.Parent = null;
+                    node.Parent = default!;
                 }
 
                 if (parent != null && parent.Parent != null)
@@ -449,7 +449,7 @@ public sealed class FibonacciHeap<T> : IEnumerable<T> where T : IComparable<T>
         var node = root;
         if (node == null)
         {
-            return null;
+            return default!;
         }
 
         do
@@ -467,7 +467,7 @@ public sealed class FibonacciHeap<T> : IEnumerable<T> where T : IComparable<T>
 
             node = node.Next;
         } while (node != root);
-        return null;
+        return default!;
     }
     IEnumerator IEnumerable.GetEnumerator()
     {
@@ -479,11 +479,11 @@ public sealed class FibonacciHeap<T> : IEnumerable<T> where T : IComparable<T>
 internal sealed class FibonacciNode<T>
 {
     #region Fields
-    private FibonacciNode<T> previous;
+    private FibonacciNode<T> previous = default!;
-    private FibonacciNode<T> next;
+    private FibonacciNode<T> next = default!;
-    private FibonacciNode<T> child;
+    private FibonacciNode<T> child = default!;
-    private FibonacciNode<T> parent;
+    private FibonacciNode<T> parent = default!;
-    private T value;
+    private T value = default!;
     private int degree;
     private bool marked;
     #endregion

SystemExtensions.NetStandard/Collections/SkipList.cs

@@ -48,7 +48,7 @@ public sealed class SkipList<T> : ICollection<T> where T : IComparable<T>
     {
         this.maxLevel = maxLevel;
         this.random = new Random();
-        this.head = new NodeSet<T>(default, maxLevel);
+        this.head = new NodeSet<T>(default!, maxLevel);
         this.end = this.head;
         for (var i = 0; i <= maxLevel; i++)
         {
@@ -242,7 +242,7 @@ public sealed class SkipList<T> : ICollection<T> where T : IComparable<T>
             return curNode;
         }
 
-        return null;
+        return default!;
     }
     #endregion
 }

SystemExtensions.NetStandard/Collections/Treap.cs

@@ -13,7 +13,7 @@ public sealed class Treap<T> : ICollection<T> where T : IComparable<T>
     {
         public TKey Key;
         public int Priority;
-        public Node<TKey> Left, Right;
+        public Node<TKey>? Left, Right;
         public Node(TKey key, int priority)
         {
             this.Key = key;
@@ -23,7 +23,7 @@ public sealed class Treap<T> : ICollection<T> where T : IComparable<T>
         }
     }
     private readonly Random randomGen;
-    private Node<T> root;
+    private Node<T> root = default!;
     private int count;
     #endregion
     #region Properties
@@ -77,7 +77,7 @@ public sealed class Treap<T> : ICollection<T> where T : IComparable<T>
     public void Clear()
     {
         this.Clear(this.root);
-        this.root = null;
+        this.root = default!;
         this.count = 0;
     }
     /// <summary>
@@ -93,7 +93,7 @@ public sealed class Treap<T> : ICollection<T> where T : IComparable<T>
     /// Returns the treap structure as an ordered array.
     /// </summary>
     /// <returns>Ordered array containing the values stored in the treap.</returns>
-    public T[] ToArray()
+    public T[]? ToArray()
     {
         if (this.root != null)
         {
@@ -104,7 +104,7 @@ public sealed class Treap<T> : ICollection<T> where T : IComparable<T>
         }
         else
         {
-            return null;
+            return default!;
         }
     }
     /// <summary>
@@ -135,16 +135,16 @@ public sealed class Treap<T> : ICollection<T> where T : IComparable<T>
         }
         else if (key.CompareTo(node.Key) <= 0)
         {
-            node.Left = this.InsertNode(node.Left, key);
+            node.Left = this.InsertNode(node.Left!, key);
-            if (node.Left.Priority > node.Priority)
+            if (node.Left!.Priority > node.Priority)
             {
                 node = this.RotateRight(node);
             }
         }
         else
         {
-            node.Right = this.InsertNode(node.Right, key);
+            node.Right = this.InsertNode(node.Right!, key);
-            if (node.Right.Priority > node.Priority)
+            if (node.Right!.Priority > node.Priority)
             {
                 node = this.RotateLeft(node);
             }
@@ -156,20 +156,20 @@ public sealed class Treap<T> : ICollection<T> where T : IComparable<T>
     {
         if (node == null)
         {
-            return node;
+            return node!;
         }
 
         if (key.CompareTo(node.Key) < 0)
         {
-            node.Left = this.RemoveNode(node.Left, key);
+            node.Left = this.RemoveNode(node.Left!, key);
         }
         else if (key.CompareTo(node.Key) > 0)
         {
-            node.Right = this.RemoveNode(node.Right, key);
+            node.Right = this.RemoveNode(node.Right!, key);
         }
         else if (node.Left == null)
         {
-            node = node.Right;
+            node = node.Right!;
         }
         else if (node.Right == null)
         {
@@ -178,26 +178,26 @@ public sealed class Treap<T> : ICollection<T> where T : IComparable<T>
         else if (node.Left.Priority < node.Right.Priority)
         {
             node = this.RotateLeft(node);
-            node.Left = this.RemoveNode(node.Left, key);
+            node.Left = this.RemoveNode(node.Left!, key);
         }
         else
         {
             node = this.RotateRight(node);
-            node.Right = this.RemoveNode(node.Right, key);
+            node.Right = this.RemoveNode(node.Right!, key);
         }
 
         return node;
     }
     private Node<T> RotateRight(Node<T> node)
     {
-        Node<T> temp = node.Left, temp2 = temp.Right;
+        Node<T> temp = node.Left!, temp2 = temp.Right!;
         temp.Right = node;
         node.Left = temp2;
         return temp;
     }
     private Node<T> RotateLeft(Node<T> node)
     {
-        Node<T> temp = node.Right, temp2 = temp.Left;
+        Node<T> temp = node.Right!, temp2 = temp.Left!;
         temp.Left = node;
         node.Right = temp2;
         return temp;
@@ -220,26 +220,26 @@ public sealed class Treap<T> : ICollection<T> where T : IComparable<T>
     {
         if (node == null)
         {
-            return node;
+            return node!;
         }
         else
         {
             if (node.Key.CompareTo(key) < 0)
             {
-                var found = this.Find(node.Left, key);
+                var found = this.Find(node.Left!, key);
                 if (found == null)
                 {
-                    found = this.Find(node.Right, key);
+                    found = this.Find(node.Right!, key);
                 }
 
                 return found;
             }
             else if (node.Key.CompareTo(key) > 0)
             {
-                var found = this.Find(node.Right, key);
+                var found = this.Find(node.Right!, key);
                 if (found == null)
                 {
-                    found = this.Find(node.Left, key);
+                    found = this.Find(node.Left!, key);
                 }
 
                 return found;
@@ -254,10 +254,10 @@ public sealed class Treap<T> : ICollection<T> where T : IComparable<T>
     {
         if (node != null)
         {
-            this.ToArray(node.Left, ref array, ref index);
+            this.ToArray(node.Left!, ref array, ref index);
             array[index] = node.Key;
             index++;
-            this.ToArray(node.Right, ref array, ref index);
+            this.ToArray(node.Right!, ref array, ref index);
         }
     }
     private IEnumerator<T> GetEnumerator(Node<T> currentNode)

SystemExtensions.NetStandard/Extensions/ObjectExtensions.cs

@@ -4,7 +4,7 @@ namespace System.Extensions;
 
 public static class ObjectExtensions
 {
-    public static T Deserialize<T>(this string serialized)
+    public static T? Deserialize<T>(this string serialized)
         where T : class
     {
         if (serialized.IsNullOrWhiteSpace())
@@ -31,7 +31,7 @@ public static class ObjectExtensions
         return (T)obj;
     }
 
-    public static T As<T>(this object obj) where T : class
+    public static T? As<T>(this object obj) where T : class
     {
         return obj as T;
     }

SystemExtensions.NetStandard/Extensions/Optional.cs

@@ -7,7 +7,7 @@ public static class Optional
         return new Optional<T>.None();
     }
 
-    public static Optional<T> FromValue<T>(T value)
+    public static Optional<T> FromValue<T>(T? value)
     {
         if (value == null)
         {
@@ -27,7 +27,7 @@ public abstract class Optional<T> : IEquatable<Optional<T>>
 
     private T Value { get; }
 
-    public T ExtractValue()
+    public T? ExtractValue()
     {
         if (this is None)
         {
@@ -38,7 +38,7 @@ public abstract class Optional<T> : IEquatable<Optional<T>>
             return this.Value;
         }
     }
-    public Optional<T> Do(Action<T> onSome, Action onNone)
+    public Optional<T> Do(Action<T>? onSome, Action? onNone)
     {
         if (onSome is null)
         {
@@ -61,7 +61,7 @@ public abstract class Optional<T> : IEquatable<Optional<T>>
 
         return this;
     }
-    public Optional<T> DoAny(Action<T> onSome = null, Action onNone = null)
+    public Optional<T> DoAny(Action<T>? onSome = default, Action? onNone = default)
     {
         if (this is Some)
         {
@@ -74,7 +74,7 @@ public abstract class Optional<T> : IEquatable<Optional<T>>
 
         return this;
     }
-    public Optional<V> Switch<V>(Func<T, V> onSome, Func<V> onNone)
+    public Optional<V> Switch<V>(Func<T, V>? onSome, Func<V>? onNone)
     {
         if (onSome is null)
         {
@@ -95,7 +95,7 @@ public abstract class Optional<T> : IEquatable<Optional<T>>
             return Optional.FromValue(onNone.Invoke());
         }
     }
-    public Optional<V> SwitchAny<V>(Func<T, V> onSome = null, Func<V> onNone = null)
+    public Optional<V> SwitchAny<V>(Func<T, V>? onSome = null, Func<V>? onNone = null)
     {
         if (this is Some)
         {
@@ -107,7 +107,7 @@ public abstract class Optional<T> : IEquatable<Optional<T>>
         }
     }
 
-    public override bool Equals(object obj)
+    public override bool Equals(object? obj)
     {
         if (obj is Optional<T>)
         {
@@ -117,17 +117,17 @@ public abstract class Optional<T> : IEquatable<Optional<T>>
         return base.Equals(obj);
     }
 
-    public bool Equals(Optional<T> other)
+    public bool Equals(Optional<T>? other)
     {
         if (this is Some && other is Some)
         {
-            return this.As<Some>().Equals(other.As<Some>());
+            return this.As<Some>() is Some some ? some.Equals(other.As<Some>()) : false;
         }
 
         return false;
     }
 
-    public static implicit operator Optional<T>(T value)
+    public static implicit operator Optional<T>(T? value)
     {
         return Optional.FromValue(value);
     }
@@ -143,7 +143,7 @@ public abstract class Optional<T> : IEquatable<Optional<T>>
         {
         }
 
-        public override bool Equals(object obj)
+        public override bool Equals(object? obj)
         {
             if (obj is Some)
             {
@@ -153,40 +153,40 @@ public abstract class Optional<T> : IEquatable<Optional<T>>
             return base.Equals(obj);
         }
 
-        public bool Equals(Some other)
+        public bool Equals(Some? other)
         {
             if (other is None)
             {
                 return false;
             }
 
-            if (other is Some)
+            if (other is not null)
             {
-                return this.Value.Equals(other.Value);
+                return this.Value is not null && this.Value.Equals(other.Value);
             }
 
             return false;
         }
 
-        public static bool operator ==(Some left, Some right)
+        public static bool operator ==(Some? left, Some right)
         {
             return left?.Equals(right) == true;
         }
 
-        public static bool operator !=(Some left, Some right)
+        public static bool operator !=(Some? left, Some right)
         {
             return left?.Equals(right) != true;
         }
 
         public override int GetHashCode()
         {
-            return this.Value is object ? this.Value.GetHashCode() : this.As<object>().GetHashCode();
+            return this.Value is object ? this.Value.GetHashCode() : this.As<object>() is object obj ? obj.GetHashCode() : 0;
         }
     }
 
     internal class None : Optional<T>
     {
-        public None() : base(default)
+        public None() : base(default!)
         {
         }
     }

SystemExtensions.NetStandard/Extensions/Result.cs

@@ -2,7 +2,7 @@
 
 public class Result<TSuccess, TFailure>
 {
-    private readonly object value;
+    private readonly object? value;
 
     public Result(TSuccess successValue)
     {
@@ -13,7 +13,7 @@ public class Result<TSuccess, TFailure>
         this.value = failureValue;
     }
 
-    public bool TryExtractSuccess(out TSuccess successValue)
+    public bool TryExtractSuccess(out TSuccess? successValue)
     {
 
         if (this.value is TSuccess success)
@@ -27,7 +27,7 @@ public class Result<TSuccess, TFailure>
             return false;
         }
     }
-    public bool TryExtractFailure(out TFailure failureValue)
+    public bool TryExtractFailure(out TFailure? failureValue)
     {
 
         if (this.value is TFailure failure)
@@ -64,7 +64,7 @@ public class Result<TSuccess, TFailure>
 
         return this;
     }
-    public Result<TSuccess, TFailure> DoAny(Action onSuccess = null, Action onFailure = null)
+    public Result<TSuccess, TFailure> DoAny(Action? onSuccess = null, Action? onFailure = null)
     {
         if (this.value is TSuccess)
         {
@@ -100,7 +100,7 @@ public class Result<TSuccess, TFailure>
 
         return this;
     }
-    public Result<TSuccess, TFailure> DoAny(Action<TSuccess> onSuccess = null, Action<TFailure> onFailure = null)
+    public Result<TSuccess, TFailure> DoAny(Action<TSuccess>? onSuccess = null, Action<TFailure>? onFailure = null)
     {
         if (this.value is TSuccess success)
         {
@@ -136,7 +136,7 @@ public class Result<TSuccess, TFailure>
 
         throw new InvalidOperationException($"{nameof(this.value)} must be of type {typeof(TSuccess)} or {typeof(TFailure)} in order to switch to {typeof(T)}");
     }
-    public T SwitchAny<T>(Func<TSuccess, T> onSuccess = null, Func<TFailure, T> onFailure = null)
+    public T? SwitchAny<T>(Func<TSuccess, T>? onSuccess = null, Func<TFailure, T>? onFailure = null)
     {
         if (this.value is TSuccess success)
         {
@@ -176,11 +176,11 @@ public class Result<TSuccess, TFailure>
     {
         if (this.value is TSuccess success)
         {
-            return Result<V, K>.Success(onSuccess is null ? default : onSuccess.Invoke(success));
+            return Result<V, K>.Success(onSuccess is not null ? onSuccess.Invoke(success) : default!);
         }
         else if (this.value is TFailure failure)
         {
-            return Result<V, K>.Failure(onFailure is null ? default : onFailure.Invoke(failure));
+            return Result<V, K>.Failure(onFailure is not null ? onFailure.Invoke(failure) : default!);
         }
 
         throw new InvalidOperationException($"{nameof(this.value)} must be of type {typeof(TSuccess)} or {typeof(TFailure)} in order to switch to Result of type {typeof(V)} or {typeof(K)}");

SystemExtensions.NetStandard/Extensions/TaskExtensions.cs

@@ -82,7 +82,7 @@ public static class TaskExtensions
             {
                 synch.EndMessageLoop();
             }
-        }, null);
+        }, default!);
         synch.BeginMessageLoop();
 
         SynchronizationContext.SetSynchronizationContext(oldContext);
@@ -115,16 +115,16 @@ public static class TaskExtensions
             {
                 synch.EndMessageLoop();
             }
-        }, null);
+        }, default!);
         synch.BeginMessageLoop();
         SynchronizationContext.SetSynchronizationContext(oldContext);
-        return ret;
+        return ret!;
     }
     
     private class ExclusiveSynchronizationContext : SynchronizationContext
     {
         private bool done;
-        public Exception InnerException { get; set; }
+        public Exception? InnerException { get; set; }
         readonly AutoResetEvent workItemsWaiting = new AutoResetEvent(false);
         readonly Queue<Tuple<SendOrPostCallback, object>> items =
             new Queue<Tuple<SendOrPostCallback, object>>();
@@ -146,14 +146,14 @@ public static class TaskExtensions
 
         public void EndMessageLoop()
         {
-            this.Post(_ => this.done = true, null);
+            this.Post(_ => this.done = true, default!);
         }
 
         public void BeginMessageLoop()
         {
             while (!this.done)
             {
-                Tuple<SendOrPostCallback, object> task = null;
+                Tuple<SendOrPostCallback, object> task = default!;
                 lock (this.items)
                 {
                     if (this.items.Count > 0)

SystemExtensions.NetStandard/Http/HttpClient.cs

@@ -19,7 +19,9 @@ public sealed class HttpClient<Tscope> : IHttpClient<Tscope>, IDisposable
         }
         remove
         {
+#pragma warning disable CS8601 // Possible null reference assignment.
             this.eventEmitted -= value;
+#pragma warning restore CS8601 // Possible null reference assignment.
         }
     }
     public Uri BaseAddress { get => this.httpClient.BaseAddress; set => this.httpClient.BaseAddress = value; }
@@ -27,20 +29,26 @@ public sealed class HttpClient<Tscope> : IHttpClient<Tscope>, IDisposable
     public long MaxResponseContentBufferSize { get => this.httpClient.MaxResponseContentBufferSize; set => this.httpClient.MaxResponseContentBufferSize = value; }
     public TimeSpan Timeout { get => this.httpClient.Timeout; set => this.httpClient.Timeout = value; }
 
+#pragma warning disable CS8618 // Non-nullable field must contain a non-null value when exiting constructor. Consider declaring as nullable.
     public HttpClient()
+#pragma warning restore CS8618 // Non-nullable field must contain a non-null value when exiting constructor. Consider declaring as nullable.
     {
         this.httpClient = new HttpClient();
         this.scope = typeof(Tscope);
     }
 
+#pragma warning disable CS8618 // Non-nullable field must contain a non-null value when exiting constructor. Consider declaring as nullable.
     public HttpClient(
+#pragma warning restore CS8618 // Non-nullable field must contain a non-null value when exiting constructor. Consider declaring as nullable.
         HttpMessageHandler handler)
     {
         this.httpClient = new HttpClient(handler);
         this.scope = typeof(Tscope);
     }
 
+#pragma warning disable CS8618 // Non-nullable field must contain a non-null value when exiting constructor. Consider declaring as nullable.
     public HttpClient(
+#pragma warning restore CS8618 // Non-nullable field must contain a non-null value when exiting constructor. Consider declaring as nullable.
         HttpMessageHandler handler,
         bool disposeHandler)
     {

SystemExtensions.NetStandard/SystemExtensions.NetStandard.csproj

@@ -7,10 +7,11 @@
     <PackageLicenseFile>LICENSE</PackageLicenseFile>
     <PackageRequireLicenseAcceptance>true</PackageRequireLicenseAcceptance>
     <RootNamespace>System</RootNamespace>
-    <Version>1.5</Version>
+    <Version>1.6</Version>
     <Authors>Alexandru Macocian</Authors>
     <RepositoryUrl>https://github.com/AlexMacocian/SystemExtensions</RepositoryUrl>
     <Description>Extensions for the System namespace</Description>
+    <Nullable>enable</Nullable>
   </PropertyGroup>
 
   <ItemGroup>

SystemExtensions.NetStandard/Threading/PriorityThreadPool.cs

@@ -111,7 +111,7 @@ public class PriorityThreadPool : IDisposable
     /// </summary>
     private volatile List<WorkerThread> threadpool;
     private volatile PriorityQueue<QueueEntry> tasks;
-    private Thread observer;
+    private Thread? observer;
     private CancellationTokenSource observerCancellationTokenSource = new CancellationTokenSource();
     private readonly object tasksLock = new object();
     private struct WorkerThread
@@ -307,7 +307,7 @@ public class PriorityThreadPool : IDisposable
                 //Finally, release the lock and invoke the task.
 
                 thisWorkerThread.Working = true;
-                QueueEntry task = null;
+                QueueEntry task = default!;
                 while (!Monitor.TryEnter(this.tasksLock))
                 {
                     ;
@@ -451,7 +451,7 @@ public class PriorityThreadPool : IDisposable
     /// Find a thread with Lowest or BelowNormal priority.
     /// </summary>
     /// <returns>Thread with low priority.</returns>
-    private Thread FindThreadWithLowPriority()
+    private Thread? FindThreadWithLowPriority()
     {
         foreach (var t in this.threadpool)
         {
@@ -461,13 +461,13 @@ public class PriorityThreadPool : IDisposable
             }
         }
 
-        return null;
+        return default;
     }
     /// <summary>
     /// Find a thread with BelowNormal or Normal priority.
     /// </summary>
     /// <returns>Thread with BelowNormal or Normal priority.</returns>
-    private Thread FindThreadWithAcceptablePriority()
+    private Thread? FindThreadWithAcceptablePriority()
     {
         foreach (var t in this.threadpool)
         {
@@ -477,7 +477,7 @@ public class PriorityThreadPool : IDisposable
             }
         }
 
-        return null;
+        return default;
     }
     /// <summary>
     /// Downgrades the priority of a thread one level.
@@ -560,9 +560,9 @@ public class PriorityThreadPool : IDisposable
                 this.tasks.Clear();
             }
 
-            this.threadpool = null;
+            this.threadpool = default!;
-            this.tasks = null;
+            this.tasks = default!;
-            this.observer = null;
+            this.observer = default;
             this.disposedValue = true;
         }
     }

SystemExtensions.NetStandard/WebSockets/ClientWebSocket.cs

@@ -0,0 +1,88 @@
+using Microsoft.Extensions.Logging;
+using System.Extensions;
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace System.Net.WebSockets;
+
+// TODO: Cannot properly test because ClientWebSocket is sealed
+public sealed class ClientWebSocket<TScope> : IClientWebSocket<TScope>, IDisposable
+{
+    private readonly ILogger<TScope>? logger;
+    private readonly ClientWebSocket internalWebSocket = new();
+
+    public ClientWebSocketOptions Options => this.internalWebSocket.Options;
+
+    public WebSocketCloseStatus? CloseStatus => this.internalWebSocket.CloseStatus;
+
+    public string CloseStatusDescription => this.internalWebSocket.CloseStatusDescription;
+
+    public string SubProtocol => this.internalWebSocket.SubProtocol;
+
+    public WebSocketState State => this.internalWebSocket.State;
+
+    public ClientWebSocket()
+    {
+    }
+
+    public ClientWebSocket(ILogger<TScope> logger)
+    {
+        this.logger = logger.ThrowIfNull(nameof(logger));
+    }
+
+    public ClientWebSocket(ClientWebSocket clientWebSocket, ILogger<TScope> logger)
+    {
+        this.internalWebSocket = clientWebSocket.ThrowIfNull(nameof(clientWebSocket));
+        this.logger = logger.ThrowIfNull(nameof(logger));
+    }
+
+    public void Dispose()
+    {
+        this.internalWebSocket?.Dispose();
+    }
+
+    public void Abort()
+    {
+        this.internalWebSocket.Abort();
+    }
+
+    public Task CloseAsync(WebSocketCloseStatus closeStatus, string statusDescription, CancellationToken cancellationToken)
+    {
+        var scopedLogger = this.logger?.CreateScopedLogger(nameof(CloseAsync), string.Empty);
+        scopedLogger?.LogInformation($"Closing websocket. Status [{closeStatus}]. Status Description [{statusDescription}]");
+        return this.internalWebSocket.CloseAsync(closeStatus, statusDescription, cancellationToken);
+    }
+
+    public Task CloseOutputAsync(WebSocketCloseStatus closeStatus, string statusDescription, CancellationToken cancellationToken)
+    {
+        var scopedLogger = this.logger?.CreateScopedLogger(nameof(CloseOutputAsync), string.Empty);
+        scopedLogger?.LogInformation($"Closing output. Status [{closeStatus}]. Status Description [{statusDescription}]");
+        return this.internalWebSocket.CloseOutputAsync(closeStatus, statusDescription, cancellationToken);
+    }
+
+    public Task ConnectAsync(Uri uri, CancellationToken cancellationToken)
+    {
+        var scopedLogger = this.logger?.CreateScopedLogger(nameof(ConnectAsync), string.Empty);
+        scopedLogger?.LogInformation($"Connecting to {uri}");
+        return this.ConnectAsync(uri, cancellationToken);
+    }
+
+    public async Task<WebSocketReceiveResult> ReceiveAsync(ArraySegment<byte> buffer, CancellationToken cancellationToken)
+    {
+        var scopedLogger = this.logger?.CreateScopedLogger(nameof(ConnectAsync), string.Empty);
+        scopedLogger?.LogInformation($"Attempting to receive bytes");
+        var result = await this.ReceiveAsync(buffer, cancellationToken);
+        scopedLogger?.LogInformation($"Received message [{result.MessageType}]");
+        scopedLogger?.LogDebug($"Type: {result.MessageType}\nCount: {result.Count}\nEndOfMessage: {result.EndOfMessage}\nCloseStatus: {result.CloseStatus}\nCloseStatusDescription: {result.CloseStatusDescription}");
+
+        return result;
+    }
+
+    public Task SendAsync(ArraySegment<byte> buffer, WebSocketMessageType messageType, bool endOfMessage, CancellationToken cancellationToken)
+    {
+        var scopedLogger = this.logger?.CreateScopedLogger(nameof(SendAsync), string.Empty);
+        scopedLogger?.LogInformation($"Sending bytes");
+        scopedLogger?.LogDebug($"Type: {messageType}\nCount: {buffer.Count}\nEndOfMessage: {endOfMessage}");
+        return this.SendAsync(buffer, messageType, endOfMessage, cancellationToken);
+    }
+}

SystemExtensions.NetStandard/WebSockets/IClientWebSocket.cs

@@ -0,0 +1,31 @@
+using System.Threading.Tasks;
+using System.Threading;
+
+namespace System.Net.WebSockets;
+
+public interface IClientWebSocket<TScope>
+{
+    WebSocketCloseStatus? CloseStatus { get; }
+    
+    string CloseStatusDescription { get; }
+    
+    ClientWebSocketOptions Options { get; }
+    
+    WebSocketState State { get; }
+    
+    string SubProtocol { get; }
+
+    void Abort();
+
+    Task CloseAsync(WebSocketCloseStatus closeStatus, string statusDescription, CancellationToken cancellationToken);
+
+    Task CloseOutputAsync(WebSocketCloseStatus closeStatus, string statusDescription, CancellationToken cancellationToken);
+
+    Task ConnectAsync(Uri uri, CancellationToken cancellationToken);
+
+    void Dispose();
+
+    Task<WebSocketReceiveResult> ReceiveAsync(ArraySegment<byte> buffer, CancellationToken cancellationToken);
+
+    Task SendAsync(ArraySegment<byte> buffer, WebSocketMessageType messageType, bool endOfMessage, CancellationToken cancellationToken);
+}