Opportunistic updates

Use pattern matching
Simplify default expression
Use auto property
Use IEnumerable<T>. ToList() removed as ubsequent calls use IEnumerable<T>.

Author: IvenBach

Rubberduck.Core/UI/Command/MenuItems/CommandMenuItemBase.cs

@@ -54,7 +54,7 @@ public virtual bool EvaluateCanExecute(RubberduckParserState state)
         public virtual bool HiddenWhenDisabled => false;
         public virtual bool IsVisible => true;
         public virtual bool BeginGroup => false;
-        public virtual int DisplayOrder => default(int);
+        public virtual int DisplayOrder => default;
         public virtual Image Image => null;
         public virtual Image Mask => null;
     }

Rubberduck.Core/UI/Command/MenuItems/ParentMenus/ParentMenuItemBase.cs

@@ -201,8 +201,7 @@ private ICommandBarControl InitializeChildControl(ICommandMenuItem item)
 
         private void child_Click(object sender, CommandBarButtonClickEventArgs e)
         {
-            var item = _items.Select(kvp => kvp.Key).SingleOrDefault(menu => e.Tag.EndsWith(menu.GetType().Name)) as ICommandMenuItem;
-            if (item == null)
+            if (!(_items.Select(kvp => kvp.Key).SingleOrDefault(menu => e.Tag.EndsWith(menu.GetType().Name)) is ICommandMenuItem item))
             {
                 return;
             }

Rubberduck.Parsing/VBA/RubberduckParserState.cs

@@ -581,25 +581,24 @@ public ParserState GetModuleState(QualifiedModuleName module)
             return _moduleStates.GetOrAdd(module, new ModuleState(ParserState.Pending)).State;
         }
 
-        private readonly object _statusLockObject = new object(); 
-        private ParserState _status;
-        public ParserState Status => _status;
+        private readonly object _statusLockObject = new object();
+        public ParserState Status { get; private set; }
 
         private void SetStatusWithCancellation(ParserState value, CancellationToken token)
         {
-            if (_status != value)
+            if (Status != value)
             {
-                var oldStatus = _status;
-                _status = value;
-                OnStateChanged(this, token, _status, oldStatus);
+                var oldStatus = Status;
+                Status = value;
+                OnStateChanged(this, token, Status, oldStatus);
             }
         }
 
         public void SetStatusAndFireStateChanged(object requestor, ParserState status, CancellationToken token)
         {
             if (Status == status)
             {
-                OnStateChanged(requestor, token, status, _status);
+                OnStateChanged(requestor, token, status, Status);
             }
             else
             {

Rubberduck.Refactorings/ExtractInterface/ExtractInterfaceRefactoring.cs

@@ -171,7 +171,7 @@ private void AddExposedAttribute(IVBComponents components, IVBComponent interfac
 
         private void AddInterfaceMembersToClass(ExtractInterfaceModel model, IModuleRewriter rewriter)
         {
-            _implementInterfaceRefactoring.Refactor(model.SelectedMembers.Select(m => m.Member).ToList(), rewriter, model.InterfaceName);
+            _implementInterfaceRefactoring.Refactor(model.SelectedMembers.Select(m => m.Member), rewriter, model.InterfaceName);
         }
 
         private string GetInterfaceModuleBody(ExtractInterfaceModel model)

Rubberduck.Refactorings/ImplementInterface/ImplementInterfaceRefactoring.cs

@@ -79,7 +79,7 @@ public override void Refactor(Declaration target)
             throw new NotSupportedException();
         }
 
-        internal void Refactor(List<Declaration> members, IModuleRewriter rewriter, string interfaceName)
+        internal void Refactor(IEnumerable<Declaration> members, IModuleRewriter rewriter, string interfaceName)
         {
             AddItems(members, rewriter, interfaceName);
         }