Merge pull request #4488 from comintern/validref

Add new inspection for Excel UDFs hidden by cells.

Author: retailcoder

Rubberduck.CodeAnalysis/Inspections/Concrete/ExcelUdfNameIsValidCellReferenceInspection.cs

@@ -0,0 +1,49 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text.RegularExpressions;
+using Rubberduck.Inspections.Abstract;
+using Rubberduck.Inspections.Results;
+using Rubberduck.Parsing.Inspections;
+using Rubberduck.Parsing.Inspections.Abstract;
+using Rubberduck.Parsing.Symbols;
+using Rubberduck.Parsing.VBA;
+using Rubberduck.Resources.Inspections;
+
+namespace Rubberduck.Inspections.Inspections.Concrete
+{
+    [RequiredLibrary("Excel")]
+    public class ExcelUdfNameIsValidCellReferenceInspection : InspectionBase
+    {
+        public ExcelUdfNameIsValidCellReferenceInspection(RubberduckParserState state) : base(state) { }
+
+        private static readonly Regex ValidCellIdRegex =
+            new Regex(@"^([a-z]|[a-z]{2}|[a-w][a-z]{2}|x([a-e][a-z]|f[a-d]))(?<Row>\d+)$",
+                RegexOptions.Compiled | RegexOptions.IgnoreCase | RegexOptions.ExplicitCapture);
+
+        private static readonly HashSet<Accessibility> VisibleAsUdf = new HashSet<Accessibility> { Accessibility.Public, Accessibility.Implicit };
+
+        private const uint MaximumExcelRows = 1048576;
+
+        protected override IEnumerable<IInspectionResult> DoGetInspectionResults()
+        {
+            var excel = State.DeclarationFinder.Projects.SingleOrDefault(item => !item.IsUserDefined && item.IdentifierName == "Excel");
+            if (excel == null)
+            {
+                return Enumerable.Empty<IInspectionResult>();
+            }
+
+            var candidates = UserDeclarations.OfType<FunctionDeclaration>().Where(decl =>
+                decl.ParentScopeDeclaration.DeclarationType == DeclarationType.ProceduralModule &&
+                VisibleAsUdf.Contains(decl.Accessibility));
+
+            return (from function in candidates.Where(decl => ValidCellIdRegex.IsMatch(decl.IdentifierName))
+                    let row = Convert.ToUInt32(ValidCellIdRegex.Matches(function.IdentifierName)[0].Groups["Row"].Value)
+                    where row > 0 && row <= MaximumExcelRows && !IsIgnoringInspectionResultFor(function, AnnotationName)
+                    select new DeclarationInspectionResult(this,
+                        string.Format(InspectionResults.ExcelUdfNameIsValidCellReferenceInspection, function.IdentifierName),
+                        function))
+                .Cast<IInspectionResult>().ToList();
+        }
+    }
+}

Rubberduck.CodeAnalysis/QuickFixes/RenameDeclarationQuickFix.cs

@@ -1,6 +1,7 @@
 using System.Globalization;
 using Rubberduck.Inspections.Abstract;
 using Rubberduck.Inspections.Concrete;
+using Rubberduck.Inspections.Inspections.Concrete;
 using Rubberduck.Interaction;
 using Rubberduck.Parsing.Inspections.Abstract;
 using Rubberduck.Parsing.Rewriter;
@@ -20,7 +21,11 @@ public sealed class RenameDeclarationQuickFix : QuickFixBase
         private readonly IMessageBox _messageBox;
 
         public RenameDeclarationQuickFix(IVBE vbe, RubberduckParserState state, IMessageBox messageBox, IRewritingManager rewritingManager)
-            : base(typeof(HungarianNotationInspection), typeof(UseMeaningfulNameInspection), typeof(DefaultProjectNameInspection), typeof(UnderscoreInPublicClassModuleMemberInspection))
+            : base(typeof(HungarianNotationInspection), 
+                typeof(UseMeaningfulNameInspection),
+                typeof(DefaultProjectNameInspection), 
+                typeof(UnderscoreInPublicClassModuleMemberInspection),
+                typeof(ExcelUdfNameIsValidCellReferenceInspection))
         {
             _vbe = vbe;
             _state = state;

Rubberduck.Core/Properties/Settings.Designer.cs

@@ -81,4 +81,17 @@
       <Version>2.0.20525</Version>
     </PackageReference>
   </ItemGroup>
+  <ItemGroup>
+    <Compile Update="Properties\Settings.Designer.cs">
+      <DesignTime>True</DesignTime>
+      <AutoGen>True</AutoGen>
+      <DependentUpon>Settings.settings</DependentUpon>
+    </Compile>
+  </ItemGroup>
+  <ItemGroup>
+    <None Update="Properties\Settings.settings">
+      <Generator>SettingsSingleFileGenerator</Generator>
+      <LastGenOutput>Settings.Designer.cs</LastGenOutput>
+    </None>
+  </ItemGroup>
 </Project>

Rubberduck.Core/Properties/Settings.settings

@@ -355,4 +355,7 @@ If the parameter can be null, ignore this inspection result; passing a null valu
   <data name="ExcelMemberMayReturnNothingInspection" xml:space="preserve">
     <value>A procedure that returns an object may return 'Nothing'. That will cause a runtime error 91 - "Object variable or With block variable not set" on subsequent member access. Perform an 'Is Nothing' check after the 'Set' assignment to guard against runtime errors.</value>
   </data>
+  <data name="ExcelUdfNameIsValidCellReferenceInspection" xml:space="preserve">
+    <value>Functions that are visible to Excel as User-Defined Functions will return a '#REF' error when used on a Worksheet if they match the name of a valid cell reference. If the function is intended to be used as a UDF, it must be renamed. If the function is not intended to be used as a UDF, it should be scoped as 'Private' or moved out of a standard Module.</value>
+  </data>
 </root>

Rubberduck.Core/Rubberduck.Core.csproj

@@ -354,4 +354,7 @@
   <data name="ExcelMemberMayReturnNothingInspection" xml:space="preserve">
     <value>Member access may return 'Nothing'</value>
   </data>
+  <data name="ExcelUdfNameIsValidCellReferenceInspection" xml:space="preserve">
+    <value>Function is hidden by Excel cell reference</value>
+  </data>
 </root>