From 39c2c7118c49a781477a0c4b122c09598029ceee Mon Sep 17 00:00:00 2001
From: Muaaz Mahmud <mmahmud@desire2learn.com>
Date: Thu, 2 Apr 2026 13:50:11 -0400
Subject: [PATCH] SPLA-3311: Allow string.Empty for ConstantAttributeAnalyzer

---
 .../ApiUsage/ConstantAttributeAnalyzer.cs        | 16 ++++++++++++----
 .../Specs/ConstantAttributeAnalyzer.cs           |  7 +++++++
 2 files changed, 19 insertions(+), 4 deletions(-)

diff --git a/src/D2L.CodeStyle.Analyzers/ApiUsage/ConstantAttributeAnalyzer.cs b/src/D2L.CodeStyle.Analyzers/ApiUsage/ConstantAttributeAnalyzer.cs
index 74178f92..5c9beab8 100644
--- a/src/D2L.CodeStyle.Analyzers/ApiUsage/ConstantAttributeAnalyzer.cs
+++ b/src/D2L.CodeStyle.Analyzers/ApiUsage/ConstantAttributeAnalyzer.cs
@@ -118,8 +118,8 @@ ISymbol constantAttribute
 				return;
 			}
 
-			// Argument is a constant value, so do nothing
-			if( argument.Value.ConstantValue.HasValue ) {
+			// Argument is a constant value or string.Empty, so do nothing
+			if( argument.Value.ConstantValue.HasValue || IsStringEmpty( argument.Value ) ) {
 				return;
 			}
 
@@ -157,9 +157,9 @@ INamedTypeSymbol constantAttribute
 				return;
 			}
 
-			// Operand is a constant value, so trust it
+			// Operand is a constant value or string.Empty, so trust it
 			IOperation operand = conversion.Operand;
-			if( operand.ConstantValue.HasValue ) {
+			if( operand.ConstantValue.HasValue || IsStringEmpty( operand ) ) {
 				return;
 			}
 
@@ -216,6 +216,14 @@ ISymbol attributeSymbol
 				);
 		}
 
+		private static bool IsStringEmpty( IOperation operation ) {
+			if( operation is IFieldReferenceOperation fieldRef ) {
+				return fieldRef.Field.ContainingType.SpecialType == SpecialType.System_String
+					&& fieldRef.Field.Name == "Empty";
+			}
+			return false;
+		}
+
 		private static bool TypeCanBeConstant( SpecialType specialType ) {
 			switch( specialType ) {
 				case SpecialType.System_Enum:
diff --git a/tests/D2L.CodeStyle.Analyzers.Test/Specs/ConstantAttributeAnalyzer.cs b/tests/D2L.CodeStyle.Analyzers.Test/Specs/ConstantAttributeAnalyzer.cs
index 255ffb53..8f2abac7 100644
--- a/tests/D2L.CodeStyle.Analyzers.Test/Specs/ConstantAttributeAnalyzer.cs
+++ b/tests/D2L.CodeStyle.Analyzers.Test/Specs/ConstantAttributeAnalyzer.cs
@@ -80,6 +80,7 @@ void Method() {
 
 			Logger.Error( CONSTANT_MESSAGE );
 			Logger.Error( "Organization 1 is constant." );
+			Logger.Error( string.Empty );
 			Logger.Error( /* NonConstantPassedToConstantParameter(message) */ string.Format(CONSTANT_MESSAGE, orgId) /**/ );
 			Logger.Error( /* NonConstantPassedToConstantParameter(message) */ $"Organization {orgId} is not constant." /**/ );
 
@@ -94,12 +95,14 @@ void Method() {
 			Types.SomeMethodWithConstantParameter<string>( "This is a constant message" );
 			Types.SomeMethodWithConstantParameter<string>( CONSTANT_STR );
 			Types.SomeMethodWithConstantParameter<string>( CONSTANT_STR + "This is a constant message" );
+			Types.SomeMethodWithConstantParameter<string>( string.Empty );
 			Types.SomeMethodWithConstantParameter<string>( /* NonConstantPassedToConstantParameter(param1) */ CONSTANT_STR + variableStr /**/ );
 			Types.SomeMethodWithConstantParameter<string>( /* NonConstantPassedToConstantParameter(param1) */ variableStr /**/ );
 
 			Types.SomeMethodWithParameter<string>( "This is a constant message" );
 			Types.SomeMethodWithParameter<string>( CONSTANT_STR );
 			Types.SomeMethodWithParameter<string>( CONSTANT_STR + "This is a constant message" );
+			Types.SomeMethodWithConstantParameter<string>( string.Empty );
 			Types.SomeMethodWithParameter<string>( CONSTANT_STR + variableStr );
 			Types.SomeMethodWithParameter<string>( variableStr );
 
@@ -212,6 +215,7 @@ string untrusted
 			string variable = "bar";
 
 			new Types.ConstantStruct( "abc" );
+			new Types.ConstantStruct( string.Empty );
 			new Types.ConstantStruct( Constants.String );
 			new Types.ConstantStruct( constant );
 			new Types.ConstantStruct( trusted );
@@ -219,6 +223,7 @@ string untrusted
 			new Types.ConstantStruct( /* NonConstantPassedToConstantParameter(value) */ untrusted /**/ );
 
 			new Types.NonConstantStruct( "abc" );
+			new Types.NonConstantStruct( string.Empty );
 			new Types.NonConstantStruct( Constants.String );
 			new Types.NonConstantStruct( constant );
 			new Types.NonConstantStruct( trusted );
@@ -264,6 +269,7 @@ string untrusted
 			string variable = "bar";
 
 			{ Types.ConstantStruct v = "abc"; }
+			{ Types.ConstantStruct v = string.Empty; }
 			{ Types.ConstantStruct v = Constants.String; }
 			{ Types.ConstantStruct v = constant; }
 			{ Types.ConstantStruct v = trusted; }
@@ -271,6 +277,7 @@ string untrusted
 			{ Types.ConstantStruct v = /* NonConstantPassedToConstantParameter(value) */ untrusted /**/; }
 
 			{ Types.NonConstantStruct v = "abc"; }
+			{ Types.NonConstantStruct v = string.Empty; }
 			{ Types.NonConstantStruct v = Constants.String; }
 			{ Types.NonConstantStruct v = constant; }
 			{ Types.NonConstantStruct v = trusted; }