Expose the checked out modules on the IRewriteSession

This information can be used to determine whether there is even a chance that a rewrite will do anything. Moreover, this information will be needed to wire up the recovery of member attributes.

Author: MDoerner

Rubberduck.Parsing/Rewriter/IRewriteSession.cs

@@ -1,4 +1,5 @@
-using Rubberduck.Parsing.VBA.Parsing;
+using System.Collections.Generic;
+using Rubberduck.Parsing.VBA.Parsing;
 using Rubberduck.VBEditor;
 
 namespace Rubberduck.Parsing.Rewriter
@@ -7,6 +8,7 @@ public interface IRewriteSession
     {
         IModuleRewriter CheckOutModuleRewriter(QualifiedModuleName module);
         bool TryRewrite();
+        IReadOnlyCollection<QualifiedModuleName> CheckedOutModules { get; }
         bool IsInvalidated { get; }
         void Invalidate();
         CodeKind TargetCodeKind { get; }

Rubberduck.Parsing/Rewriter/MemberAttributeRecoverer.cs

@@ -98,14 +98,21 @@ private void ExecuteRecoveryOfAttributes(object sender, ParserStateEventArgs e)
             }
 
             StopRecoveringAttributesOnNextParse();
-            CancelTheCurrentParse();
-           
+            
             var rewriteSession = _rewritingManager.CheckOutAttributesSession();
             foreach (var module in _attributesToRecover.Keys)
             {
                 RecoverAttributes(rewriteSession, module, _attributesToRecover[module]);
             }
 
+            if (!rewriteSession.CheckedOutModules.Any())
+            {
+                //There is nothing we can do.
+                return;
+            }
+
+            CancelTheCurrentParse();
+
             Task.Run(() => rewriteSession.TryRewrite());
 
             EndTheCurrentParse(e.Token);

Rubberduck.Parsing/Rewriter/RewriteSessionBase.cs

@@ -2,6 +2,7 @@
 using System.Collections.Generic;
 using System.Linq;
 using NLog;
+using Rubberduck.Parsing.VBA.Extensions;
 using Rubberduck.Parsing.VBA.Parsing;
 using Rubberduck.VBEditor;
 
@@ -25,6 +26,7 @@ protected RewriteSessionBase(IRewriterProvider rewriterProvider, Func<IRewriteSe
             _rewritingAllowed = rewritingAllowed;
         }
 
+        public IReadOnlyCollection<QualifiedModuleName> CheckedOutModules => CheckedOutModuleRewriters.Keys.ToHashSet();
 
         public IModuleRewriter CheckOutModuleRewriter(QualifiedModuleName module)
         {