ImplicitActiveSheetReferenceInspection.cs

using System.Linq;
using Rubberduck.CodeAnalysis.Inspections.Abstract;
using Rubberduck.CodeAnalysis.Inspections.Attributes;
using Rubberduck.Parsing.Symbols;
using Rubberduck.Parsing.VBA;
using Rubberduck.Parsing.VBA.DeclarationCaching;
using Rubberduck.Resources.Inspections;

namespace Rubberduck.CodeAnalysis.Inspections.Concrete
{
    /// <summary>
    /// Locates unqualified Worksheet.Range/Cells/Columns/Rows member calls implicitly referring to ActiveSheet.
    /// </summary>
    /// <reference name="Excel" />
    /// <why>
    /// Implicit references to the active worksheet (ActiveSheet) rarely mean to be working with *whatever worksheet is currently active*. 
    /// By explicitly qualifying these member calls with a specific Worksheet object, the assumptions are removed, the code
    /// is more robust, and will be less likely to throw run-time error 1004 or produce unexpected results
    /// when the active sheet isn't the expected one.
    /// </why>
    /// <example hasResult="true">
    /// <module name="MyModule" type="Standard Module">
    /// <![CDATA[
    /// Private Sub Example()
    ///     Dim foo As Range
    ///     Set foo = Sheet1.Range(Cells(1, 1), Cells(1, 10)) ' Worksheet.Cells implicitly from ActiveSheet; error 1004 if that isn't Sheet1.
    /// End Sub
    /// ]]>
    /// </module>
    /// </example>
    /// <example hasResult="false">
    /// <module name="MyModule" type="Standard Module">
    /// <![CDATA[
    /// Private Sub Example()
    ///     Dim foo As Range
    ///     With Sheet1
    ///         Set foo = .Range(.Cells(1, 1), .Cells(1, 10)) ' all member calls are made against the With block object
    ///     End With
    /// End Sub
    /// ]]>
    /// </module>
    /// </example>
    [RequiredLibrary("Excel")]
    internal sealed class ImplicitActiveSheetReferenceInspection : ImplicitSheetReferenceInspectionBase
    {
        public ImplicitActiveSheetReferenceInspection(IDeclarationFinderProvider declarationFinderProvider)
            : base(declarationFinderProvider)
        {}

        protected override string[] GlobalObjectClassNames => new[] { "Global", "_Global", };

        protected override bool IsResultReference(IdentifierReference reference, DeclarationFinder finder)
        {
            return !(Declaration.GetModuleParent(reference.ParentNonScoping) is DocumentModuleDeclaration document)
                || !document.SupertypeNames.Contains("Worksheet");
        }

        protected override string ResultDescription(IdentifierReference reference)
        {
            return string.Format(
                InspectionResults.ImplicitActiveSheetReferenceInspection,
                reference.Declaration.IdentifierName);
        }
    }
}