fixed #3904

Collectionexpressions are detected as variable declarations and not as InitializerExpression

- Filter based on the declared variables collectionexpressions out, and then check each element

Author: Mivee

Diff for: StyleCop.Analyzers/StyleCop.Analyzers.Test.CSharp12/ReadabilityRules/SA1137CSharp12UnitTests.cs

@@ -3,9 +3,61 @@
 
 namespace StyleCop.Analyzers.Test.CSharp12.ReadabilityRules
 {
+    using System.Threading;
+    using System.Threading.Tasks;
+    using Microsoft.CodeAnalysis.Testing;
     using StyleCop.Analyzers.Test.CSharp11.ReadabilityRules;
+    using Xunit;
+    using static StyleCop.Analyzers.Test.Verifiers.StyleCopDiagnosticVerifier<
+        StyleCop.Analyzers.ReadabilityRules.SA1137ElementsShouldHaveTheSameIndentation>;
 
     public partial class SA1137CSharp12UnitTests : SA1137CSharp11UnitTests
     {
+        [Fact]
+        [WorkItem(3904, "https://github.com/DotNetAnalyzers/StyleCopAnalyzers/issues/3904")]
+        public async Task TestCollectionInitializationAsync()
+        {
+            var csharp = new CSharpTest()
+            {
+                TestSources =
+                {
+                    @"
+                    class FirstCase
+                    {
+                        private readonly System.Collections.Generic.List<string> example1 = 
+                        [
+                            ""a"",
+                    ""b"",
+                                    ""c"",
+                        ];
+                    }",
+                    @"
+                    class SecondCase
+                    {
+                        private readonly System.Collections.Generic.List<int> example2 = 
+                        [
+                            1,
+                            2,
+                    3,
+                    4,
+                        ];
+                    }",
+                    @"
+                    class ThirdCase
+                    {
+                        private readonly System.Collections.Generic.List<int> example3 = [1, 2, 3, 4];
+                    }",
+                },
+                ExpectedDiagnostics =
+                {
+                    DiagnosticResult.CompilerWarning("SA1137").WithLocation("/0/Test0.cs", 7, 1),
+                    DiagnosticResult.CompilerWarning("SA1137").WithLocation("/0/Test0.cs", 8, 1),
+                    DiagnosticResult.CompilerWarning("SA1137").WithLocation("/0/Test1.cs", 8, 1),
+                    DiagnosticResult.CompilerWarning("SA1137").WithLocation("/0/Test1.cs", 9, 1),
+                },
+            };
+
+            await csharp.RunAsync(CancellationToken.None).ConfigureAwait(false);
+        }
     }
 }

Diff for: StyleCop.Analyzers/StyleCop.Analyzers/ReadabilityRules/SA1137ElementsShouldHaveTheSameIndentation.cs

@@ -154,6 +154,17 @@ private static void HandleVariableDeclaration(SyntaxNodeAnalysisContext context)
         {
             var variableDeclaration = (VariableDeclarationSyntax)context.Node;
             CheckElements(context, variableDeclaration.Variables);
+
+            var collectionsExpressions = variableDeclaration.Variables
+                .Where(variable => IsCollectionExpression(variable))
+                .Select(filtered => filtered.Initializer.Value)
+                .ToList();
+
+            foreach (var expression in collectionsExpressions)
+            {
+                var childNodes = expression.ChildNodes().ToImmutableList();
+                CheckElements(context, childNodes);
+            }
         }
 
         private static void HandleTypeParameterList(SyntaxNodeAnalysisContext context)
@@ -539,5 +550,17 @@ private static void ReportDiagnostic(SyntaxNodeAnalysisContext context, SyntaxTo
             ImmutableDictionary<string, string> properties = ImmutableDictionary.Create<string, string>().SetItem(ExpectedIndentationKey, expectedIndentation);
             context.ReportDiagnostic(Diagnostic.Create(Descriptor, location, properties));
         }
+
+        private static bool IsCollectionExpression(VariableDeclaratorSyntax declarationSyntax)
+        {
+            if (declarationSyntax.Initializer?.Value == null)
+            {
+                return false;
+            }
+
+            // directly check for rawkind, to avoid double casting when using IsKind(SyntaxKind)
+            // ID is taken from https://source.dot.net/#Microsoft.CodeAnalysis.CSharp/Syntax/SyntaxKind.cs,925
+            return declarationSyntax.Initializer.Value.RawKind == 9076;
+        }
     }
 }