Merge pull request #5640 from MDoerner/CountForLoopAssignmentAsVariab…

…leUsage Count 'For' loop variable as self-referencing assignment, removes inspection false positive.
rubberduck-vba · Dec 1, 2020 · 06f5b03 · 06f5b03
2 parents 4dc9bab + 616999c
commit 06f5b03
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Showing 2 changed files with 48 additions and 3 deletions.
diff --git a/Rubberduck.CodeAnalysis/Inspections/Concrete/VariableNotUsedInspection.cs b/Rubberduck.CodeAnalysis/Inspections/Concrete/VariableNotUsedInspection.cs
@@ -54,7 +54,21 @@ protected override bool IsResultDeclaration(Declaration declaration, Declaration
         {
             return !declaration.IsWithEvents
                    && declaration.References
-                       .All(reference => reference.IsAssignment);
+                       .All(reference => reference.IsAssignment)
+                   && !declaration.References.Any(IsForLoopAssignment);
+        }
+
+        private bool IsForLoopAssignment(IdentifierReference reference)
+        {
+            if(!reference.IsAssignment)
+            {
+                return false;
+            }
+
+            //A For Next loop has the form For expr1 = expr2 (Step expr3) ... Next (expr1)
+            var relationalOpAncestor = reference.Context.GetAncestor<VBAParser.RelationalOpContext>();
+            return relationalOpAncestor != null
+                && relationalOpAncestor.Parent is VBAParser.ForNextStmtContext;
         }
 
         protected override IInspectionResult InspectionResult(Declaration declaration)

diff --git a/RubberduckTests/Inspections/VariableNotUsedInspectionTests.cs b/RubberduckTests/Inspections/VariableNotUsedInspectionTests.cs
@@ -96,10 +96,10 @@ public void VariableNotUsed_UsedInNameStatement_DoesNotReturnsResult()
 
             Assert.AreEqual(0, InspectionResultsForStandardModule(inputCode).Count());
         }
-
-        //https://github.com/rubberduck-vba/Rubberduck/issues/5088        
+
         [Test]
         [Category("Inspections")]
+        //See issue #5610 at https://github.com/rubberduck-vba/Rubberduck/issues/5088 
         public void VariableNotUsed_AssignedButNeverReferenced_ReturnsResult()
         {
             const string inputCode =
@@ -110,6 +110,37 @@ public void VariableNotUsed_AssignedButNeverReferenced_ReturnsResult()
 
             Assert.AreEqual(1, InspectionResultsForStandardModule(inputCode).Count());
         }
+
+        [Test]
+        [Category("Inspections")]
+        //See issue #5610 at https://github.com/rubberduck-vba/Rubberduck/issues/5610 
+        public void VariableNotUsed_AssignedinForLoop_DoesNotReturnResult()
+        {
+            const string inputCode =
+@"Sub Foo()
+    Dim counter As Long
+    For counter = 1 To 1000
+        'Try something
+    Next
+End Sub";
+
+            Assert.AreEqual(0, InspectionResultsForStandardModule(inputCode).Count());
+        }
+
+        [Test]
+        [Category("Inspections")]
+        public void VariableNotUsed_AssignedinForEachLoop_ReturnsResult()
+        {
+            const string inputCode =
+@"Sub Foo()
+    Dim var1 As Variant
+    Dim coll As Scription.Collection
+    For Each var1 In coll
+    Next
+End Sub";
+
+            Assert.AreEqual(1, InspectionResultsForStandardModule(inputCode).Count());
+        }
 
         [Test]
         [Category("Inspections")]