Update SA1212 to also trigger for an init accessor before a getter

StyleCop.Analyzers/StyleCop.Analyzers.Test.CSharp9/OrderingRules/SA1212CSharp9UnitTests.cs

@@ -3,9 +3,91 @@
 
 namespace StyleCop.Analyzers.Test.CSharp9.OrderingRules
 {
+    using System.Threading;
+    using System.Threading.Tasks;
     using StyleCop.Analyzers.Test.CSharp8.OrderingRules;
+    using StyleCop.Analyzers.Test.Verifiers;
+    using Xunit;
+    using static StyleCop.Analyzers.Test.Verifiers.StyleCopCodeFixVerifier<
+        StyleCop.Analyzers.OrderingRules.SA1212PropertyAccessorsMustFollowOrder,
+        StyleCop.Analyzers.OrderingRules.SA1212SA1213CodeFixProvider>;
 
     public class SA1212CSharp9UnitTests : SA1212CSharp8UnitTests
     {
+        [Fact]
+        [WorkItem(3652, "https://github.com/DotNetAnalyzers/StyleCopAnalyzers/issues/3652")]
+        public async Task TestAutoPropertyDeclarationInitBeforeGetterAsync()
+        {
+            var testCode = @"
+public class Foo
+{
+    public int Prop { [|init;|] get; }
+}";
+
+            var fixedCode = @"
+public class Foo
+{
+    public int Prop { get; init; }
+}";
+
+            var test = new CSharpTest
+            {
+                TestCode = testCode,
+                FixedCode = fixedCode,
+                ReferenceAssemblies = GenericAnalyzerTest.ReferenceAssembliesNet50,
+            };
+            await test.RunAsync(CancellationToken.None).ConfigureAwait(false);
+        }
+
+        [Fact]
+        [WorkItem(3652, "https://github.com/DotNetAnalyzers/StyleCopAnalyzers/issues/3652")]
+        public async Task TestPropertyWithBackingFieldDeclarationInitBeforeGetterAsync()
+        {
+            var testCode = @"
+public class Foo
+{
+    private int i = 0;
+
+    public int Prop
+    {
+        [|init
+        {
+            i = value;
+        }|]
+
+        get
+        {
+            return i;
+        }
+    }
+}";
+
+            var fixedCode = @"
+public class Foo
+{
+    private int i = 0;
+
+    public int Prop
+    {
+        get
+        {
+            return i;
+        }
+
+        init
+        {
+            i = value;
+        }
+    }
+}";
+
+            var test = new CSharpTest
+            {
+                TestCode = testCode,
+                FixedCode = fixedCode,
+                ReferenceAssemblies = GenericAnalyzerTest.ReferenceAssembliesNet50,
+            };
+            await test.RunAsync(CancellationToken.None).ConfigureAwait(false);
+        }
     }
 }

StyleCop.Analyzers/StyleCop.Analyzers.Test/OrderingRules/SA1212UnitTests.cs

@@ -339,7 +339,7 @@ public int Prop
         }
 
         [Fact]
-        public async Task TestAutoPropertydDeclarationSetterBeforeGetterAsync()
+        public async Task TestAutoPropertyDeclarationSetterBeforeGetterAsync()
         {
             var testCode = @"
 public class Foo

StyleCop.Analyzers/StyleCop.Analyzers/Lightup/SyntaxKindEx.cs

@@ -62,6 +62,7 @@ internal static class SyntaxKindEx
         public const SyntaxKind NullableDirectiveTrivia = (SyntaxKind)9055;
         public const SyntaxKind FunctionPointerType = (SyntaxKind)9056;
         public const SyntaxKind FunctionPointerParameter = (SyntaxKind)9057;
+        public const SyntaxKind InitAccessorDeclaration = (SyntaxKind)9060;
         public const SyntaxKind WithExpression = (SyntaxKind)9061;
         public const SyntaxKind WithInitializerExpression = (SyntaxKind)9062;
         public const SyntaxKind RecordDeclaration = (SyntaxKind)9063;

StyleCop.Analyzers/StyleCop.Analyzers/OrderingRules/SA1212PropertyAccessorsMustFollowOrder.cs

@@ -11,6 +11,7 @@ namespace StyleCop.Analyzers.OrderingRules
     using Microsoft.CodeAnalysis.CSharp;
     using Microsoft.CodeAnalysis.CSharp.Syntax;
     using Microsoft.CodeAnalysis.Diagnostics;
+    using StyleCop.Analyzers.Lightup;
 
     /// <summary>
     /// A get accessor appears after a set accessor within a property or indexer.
@@ -99,7 +100,7 @@ private static void AnalyzeProperty(SyntaxNodeAnalysisContext context, BasePrope
                 return;
             }
 
-            if (accessors[0].Kind() == SyntaxKind.SetAccessorDeclaration &&
+            if ((accessors[0].Kind() == SyntaxKind.SetAccessorDeclaration || accessors[0].Kind() == SyntaxKindEx.InitAccessorDeclaration) &&
                 accessors[1].Kind() == SyntaxKind.GetAccessorDeclaration)
             {
                 context.ReportDiagnostic(Diagnostic.Create(Descriptor, accessors[0].GetLocation()));

documentation/SA1212.md

@@ -17,11 +17,11 @@
 
 ## Cause
 
-A get accessor appears after a set accessor within a property or indexer.
+A get accessor appears after a set or init accessor within a property or indexer.
 
 ## Rule description
 
-A violation of this rule occurs when a get accessor is placed after a set accessor within a property or indexer. To comply with this rule, the get accessor should appear before the set accessor.
+A violation of this rule occurs when a get accessor is placed after a set or init accessor within a property or indexer. To comply with this rule, the get accessor should appear first.
 
 For example, the following code would raise an instance of this violation: