Fix NRE in remove when rejecting interface prompt. More tests.

Author: Hosch250

RetailCoder.VBE/Refactorings/RemoveParameters/RemoveParametersModel.cs

@@ -19,10 +19,13 @@ public class RemoveParametersModel
         public Declaration TargetDeclaration { get; private set; }
         public List<Parameter> Parameters { get; set; }
 
-        public RemoveParametersModel(VBProjectParseResult parseResult, QualifiedSelection selection)
+        private readonly IMessageBox _messageBox;
+
+        public RemoveParametersModel(VBProjectParseResult parseResult, QualifiedSelection selection, IMessageBox messageBox)
         {
             _parseResult = parseResult;
             _declarations = parseResult.Declarations;
+            _messageBox = messageBox;
 
             AcquireTarget(selection);
 
@@ -39,6 +42,8 @@ private void AcquireTarget(QualifiedSelection selection)
 
         private void LoadParameters()
         {
+            if (TargetDeclaration == null) { return; }
+
             Parameters.Clear();
 
             var index = 0;
@@ -89,12 +94,14 @@ private Declaration PromptIfTargetImplementsInterface()
             var interfaceMember = Declarations.FindInterfaceMember(interfaceImplementation);
             var message = string.Format(RubberduckUI.Refactoring_TargetIsInterfaceMemberImplementation, declaration.IdentifierName, interfaceMember.ComponentName, interfaceMember.IdentifierName);
 
-            var confirm = MessageBox.Show(message, RubberduckUI.ReorderParamsDialog_TitleText, MessageBoxButtons.YesNo, MessageBoxIcon.Exclamation);
+            var confirm = _messageBox.Show(message, RubberduckUI.ReorderParamsDialog_TitleText, MessageBoxButtons.YesNo, MessageBoxIcon.Exclamation);
             return confirm == DialogResult.No ? null : interfaceMember;
         }
 
         private Declaration GetGetter()
         {
+            if (TargetDeclaration == null) { return null; }
+
             if (TargetDeclaration.DeclarationType != DeclarationType.PropertyLet &&
                 TargetDeclaration.DeclarationType != DeclarationType.PropertySet)
             {

RetailCoder.VBE/Refactorings/RemoveParameters/RemoveParametersPresenter.cs

@@ -21,6 +21,8 @@ public RemoveParametersPresenter(IRemoveParametersView view, RemoveParametersMod
 
         public RemoveParametersModel Show()
         {
+            if (_model.TargetDeclaration == null) { return null; }
+
             if (_model.Parameters.Count == 0)
             {
                 var message = string.Format(RubberduckUI.RemovePresenter_NoParametersError, _model.TargetDeclaration.IdentifierName);

RetailCoder.VBE/Refactorings/RemoveParameters/RemoveParametersPresenterFactory.cs

@@ -1,4 +1,5 @@
 using Rubberduck.Parsing;
+using Rubberduck.UI;
 using Rubberduck.VBEditor;
 
 namespace Rubberduck.Refactorings.RemoveParameters
@@ -25,7 +26,7 @@ public RemoveParametersPresenter Create()
                 return null;
             }
 
-            var model = new RemoveParametersModel(_parseResult, selection.Value);
+            var model = new RemoveParametersModel(_parseResult, selection.Value, new RubberduckMessageBox());
             return new RemoveParametersPresenter(_view, model);
         }
     }

RetailCoder.VBE/Refactorings/RemoveParameters/RemoveParametersRefactoring.cs

@@ -57,7 +57,7 @@ public void Refactor(Declaration target)
 
         public void QuickFix(VBProjectParseResult parseResult, QualifiedSelection selection)
         {
-            _model = new RemoveParametersModel(parseResult, selection);
+            _model = new RemoveParametersModel(parseResult, selection, null);
             var target = _model.Declarations.FindSelection(selection, new[] { DeclarationType.Parameter });
 
             // ReSharper disable once PossibleUnintendedReferenceComparison