Merge pull request #5860 from MDoerner/FixVariableNotAssignedForVariantsUsedAsArrays

Fix VariableNotAssigned for Variants used as arrays

Author: retailcoder

Rubberduck.CodeAnalysis/Inspections/Concrete/VariableNotAssignedInspection.cs

@@ -51,7 +51,9 @@ protected override bool IsResultDeclaration(Declaration declaration, Declaration
                    && !declaration.IsWithEvents
                    && !declaration.IsSelfAssigned
                    && !HasUdtType(declaration, finder) // UDT variables don't need to be assigned
-                   && !declaration.References.Any(reference => reference.IsAssignment || IsAssignedByRefArgument(reference.ParentScoping, reference, finder));
+                   && !declaration.References.Any(reference => reference.IsAssignment 
+                                                               || reference.IsReDim //Ignores Variants used as arrays without assignment of an existing one.
+                                                               || IsAssignedByRefArgument(reference.ParentScoping, reference, finder));
         }
 
         private static bool HasUdtType(Declaration declaration, DeclarationFinder finder)

Rubberduck.Parsing/Symbols/Declaration.cs

@@ -382,7 +382,8 @@ public IdentifierReference AddReference(
             bool isArrayAccess = false,
             bool isProcedureCoercion = false,
             bool isInnerRecursiveDefaultMemberAccess = false,
-            IdentifierReference qualifyingReference = null
+            IdentifierReference qualifyingReference = null,
+            bool isReDim = false
             )
         {
             var oldReference = _references.FirstOrDefault(r =>
@@ -416,7 +417,8 @@ public IdentifierReference AddReference(
                 isArrayAccess,
                 isProcedureCoercion,
                 isInnerRecursiveDefaultMemberAccess,
-                qualifyingReference);
+                qualifyingReference,
+                isReDim);
             _references.AddOrUpdate(newReference, 1, (key, value) => 1);
             return newReference;
         }

Rubberduck.Parsing/Symbols/IdentifierReference.cs

@@ -31,7 +31,8 @@ internal IdentifierReference(
             bool isArrayAccess = false,
             bool isProcedureCoercion = false,
             bool isInnerRecursiveDefaultMemberAccess = false,
-            IdentifierReference qualifyingReference = null)
+            IdentifierReference qualifyingReference = null,
+            bool isReDim = false)
         {
             ParentScoping = parentScopingDeclaration;
             ParentNonScoping = parentNonScopingDeclaration;
@@ -50,6 +51,7 @@ internal IdentifierReference(
             Annotations = annotations ?? new List<IParseTreeAnnotation>();
             IsInnerRecursiveDefaultMemberAccess = isInnerRecursiveDefaultMemberAccess;
             QualifyingReference = qualifyingReference;
+            IsReDim = isReDim;
         }
 
         public QualifiedSelection QualifiedSelection { get; }
@@ -84,6 +86,7 @@ internal IdentifierReference(
         public int DefaultMemberRecursionDepth { get; }
 
         public bool IsArrayAccess { get; }
+        public bool IsReDim { get; }
 
         public ParserRuleContext Context { get; }
 

Rubberduck.Parsing/VBA/ReferenceManagement/BoundExpressionVisitor.cs

@@ -24,9 +24,10 @@ public void AddIdentifierReferences(
             Declaration parent,
             bool isAssignmentTarget = false,
             bool hasExplicitLetStatement = false,
-            bool isSetAssignment = false)
+            bool isSetAssignment = false,
+            bool isReDim = false)
         {
-            Visit(boundExpression, module, scope, parent, isAssignmentTarget, hasExplicitLetStatement, isSetAssignment);
+            Visit(boundExpression, module, scope, parent, isAssignmentTarget, hasExplicitLetStatement, isSetAssignment, isReDim: isReDim);
         }
 
         /// <summary>
@@ -50,12 +51,13 @@ private IdentifierReference Visit(
             bool isAssignmentTarget = false,
             bool hasExplicitLetStatement = false,
             bool isSetAssignment = false,
-            bool hasArrayAccess = false)
+            bool hasArrayAccess = false,
+            bool isReDim = false)
         {
             switch (boundExpression)
             {
                 case SimpleNameExpression simpleNameExpression:
-                    return Visit(simpleNameExpression, module, scope, parent, isAssignmentTarget, hasExplicitLetStatement, isSetAssignment);
+                    return Visit(simpleNameExpression, module, scope, parent, isAssignmentTarget, hasExplicitLetStatement, isSetAssignment, isReDim);
                 case MemberAccessExpression memberAccessExpression:
                     return Visit(memberAccessExpression, module, scope, parent, isAssignmentTarget, hasExplicitLetStatement, isSetAssignment);
                 case IndexExpression indexExpression:
@@ -119,7 +121,8 @@ private IdentifierReference Visit(
             Declaration parent,
             bool isAssignmentTarget,
             bool hasExplicitLetStatement,
-            bool isSetAssignment)
+            bool isSetAssignment,
+            bool isReDim)
         {
             var callSiteContext = expression.Context;
             var callee = expression.ReferencedDeclaration;
@@ -136,7 +139,8 @@ private IdentifierReference Visit(
                 FindIdentifierAnnotations(module, selection.StartLine),
                 isAssignmentTarget,
                 hasExplicitLetStatement,
-                isSetAssignment);
+                isSetAssignment,
+                isReDim: isReDim);
         }
 
         private IEnumerable<IParseTreeAnnotation> FindIdentifierAnnotations(QualifiedModuleName module, int line)

Rubberduck.Parsing/VBA/ReferenceManagement/IdentifierReferenceResolver.cs

@@ -169,7 +169,8 @@ private void ResolveDefault(
             StatementResolutionContext statementContext = StatementResolutionContext.Undefined,
             bool isAssignmentTarget = false,
             bool hasExplicitLetStatement = false,
-            bool isSetAssignment = false)
+            bool isSetAssignment = false,
+            bool isReDim = false)
         {
             var withExpression = GetInnerMostWithExpression();
             var boundExpression = _bindingService.ResolveDefault(
@@ -190,7 +191,8 @@ private void ResolveDefault(
                 _currentParent,
                 isAssignmentTarget,
                 hasExplicitLetStatement, 
-                isSetAssignment);
+                isSetAssignment,
+                isReDim);
         }
 
         private void ResolveType(ParserRuleContext expression)
@@ -258,7 +260,7 @@ public void Resolve(VBAParser.RedimStmtContext context)
                 // The indexedExpression is the array that is being resized.
                 // We can't treat it as a normal index expression because the semantics are different.
                 // It's not actually a function call but a special statement.
-                ResolveDefault(indexedExpression, false);
+                ResolveDefault(indexedExpression, false, isReDim: true);
                 if (argumentList.argument() != null)
                 {
                     foreach (var positionalArgument in argumentList.argument())

RubberduckTests/Inspections/VariableNotAssignedInspectionTests.cs

@@ -379,6 +379,47 @@ End Sub
             ).Count());
         }
 
+        [Test]
+        [Category("Inspections")]
+        public void VariableNotAssigned_ArrayWithElementAssignment_DoesNotReturnResult()
+        {
+            const string inputCode = @"
+Public Sub Foo()
+    Dim arr(0 To 0) As Variant
+    arr(0) = 42
+End Sub
+";
+            Assert.AreEqual(0, InspectionResultsForStandardModule(inputCode).Count());
+        }
+
+        [Test]
+        [Category("Inspections")]
+        public void VariableNotAssigned_ReDimDeclaredArrayWithElementAssignment_DoesNotReturnResult()
+        {
+            const string inputCode = @"
+Public Sub Foo()
+    ReDim arr(0 To 0) As Variant
+    arr(0) = 42
+End Sub
+";
+            Assert.AreEqual(0, InspectionResultsForStandardModule(inputCode).Count());
+        }
+
+        [Test]
+        [Category("Inspections")]
+        //See issue #5845 at https://github.com/rubberduck-vba/Rubberduck/issues/5845
+        public void VariableNotAssigned_VariantUsedAsArrayWithElementAssignment_DoesNotReturnResult()
+        {
+            const string inputCode = @"
+Public Sub Foo()
+    Dim arr As Variant
+    ReDim arr(0 To 0) As Variant
+    arr(0) = 42
+End Sub
+";
+            Assert.AreEqual(0, InspectionResultsForStandardModule(inputCode).Count());
+        }
+
         [Test]
         [Category("Inspections")]
         public void VariableNotAssigned_Ignored_DoesNotReturnResult()