Allow null forgiving operator at end of line when followed by colon in conditional expression

Author: EdwinEngelen

StyleCop.Analyzers/StyleCop.Analyzers.Test.CSharp8/SpacingRules/SA1003CSharp8UnitTests.cs

@@ -359,6 +359,32 @@ public void TestOnMethod()
         }
     }
 }
+";
+
+            await VerifyCSharpDiagnosticAsync(testCode, DiagnosticResult.EmptyDiagnosticResults, CancellationToken.None).ConfigureAwait(false);
+        }
+
+        [Fact]
+        public async Task TestNullForgivingOperatorAtEndOfLineBeforeConditionalExpressionColonAsync()
+        {
+            var testCode = @"
+namespace TestNamespace
+{
+    public class TestClass
+    {
+        public void TestMethod(bool condition, string? canBeNullExpression)
+        {
+            var result1 = condition ? canBeNullExpression!
+                : ""default"";
+
+            var result2 = condition
+                ? canBeNullExpression!
+                : ""default"";
+
+            var result3 = condition ? canBeNullExpression! : ""default"";
+        }
+    }
+}
 ";
 
             await VerifyCSharpDiagnosticAsync(testCode, DiagnosticResult.EmptyDiagnosticResults, CancellationToken.None).ConfigureAwait(false);

StyleCop.Analyzers/StyleCop.Analyzers/SpacingRules/SA1003SymbolsMustBeSpacedCorrectly.cs

@@ -393,6 +393,7 @@ private static void HandlePostfixUnaryExpression(SyntaxNodeAnalysisContext conte
                 break;
             }
 
+            // Determine if the operator is allowed at the end of a line
             bool allowEndOfLine;
             if (followingToken.IsKind(SyntaxKind.CloseBraceToken))
             {
@@ -405,6 +406,13 @@ private static void HandlePostfixUnaryExpression(SyntaxNodeAnalysisContext conte
                 // Allow null forgiving operator at end of line when followed by member access on the next line
                 allowEndOfLine = true;
             }
+            else if (followingToken.IsKind(SyntaxKind.ColonToken) && 
+                     followingToken.Parent is ConditionalExpressionSyntax &&
+                     followingToken.IsFirstInLine())
+            {
+                // Allow null forgiving operator at end of line when followed by colon in conditional expression on the next line
+                allowEndOfLine = true;
+            }
             else
             {
                 allowEndOfLine = false;