Update SA1011 for nullable reference types

Author: sharwell

StyleCop.Analyzers/StyleCop.Analyzers.Test.CSharp8/SpacingRules/SA1011CSharp8UnitTests.cs

@@ -1,8 +1,6 @@
 // Copyright (c) Tunnel Vision Laboratories, LLC. All Rights Reserved.
 // Licensed under the MIT License. See LICENSE in the project root for license information.
 
-#nullable disable
-
 namespace StyleCop.Analyzers.Test.CSharp8.SpacingRules
 {
     using System.Threading;
@@ -16,6 +14,65 @@ namespace StyleCop.Analyzers.Test.CSharp8.SpacingRules
 
     public partial class SA1011CSharp8UnitTests : SA1011CSharp7UnitTests
     {
+        [Fact]
+        [WorkItem(3006, "https://github.com/DotNetAnalyzers/StyleCopAnalyzers/issues/3006")]
+        public async Task VerifyNullableArrayAnnotationsAsync()
+        {
+            var testCode = @"#nullable enable
+namespace TestNamespace
+{
+    public class TestClass
+    {
+        private string[]? field1;
+        private string[]?[]? field2;
+        private string?[][]? field3;
+
+        public string[]? Property1 => field1;
+
+        public string[]?[]? Property2
+        {
+            get
+            {
+                return new string[]?[] { field1, field2?[0] };
+            }
+        }
+
+        public string?[] Method(string?[]? values, string[]?[]? other)
+        {
+            return values ?? new string?[] { null, other?[0]?[0] };
+        }
+    }
+}
+";
+
+            await VerifyCSharpDiagnosticAsync(testCode, DiagnosticResult.EmptyDiagnosticResults, CancellationToken.None).ConfigureAwait(false);
+        }
+
+        [Fact]
+        [WorkItem(3006, "https://github.com/DotNetAnalyzers/StyleCopAnalyzers/issues/3006")]
+        public async Task VerifyNullForgivingAfterElementAccessAndArrayCreationAsync()
+        {
+            var testCode = @"#nullable enable
+namespace TestNamespace
+{
+    public class TestClass
+    {
+        public string GetValue(string[]? values)
+        {
+            return values![0]!;
+        }
+
+        public int GetLength(string?[] items)
+        {
+            return new string?[0]!.Length + items[0]! .Length;
+        }
+    }
+}
+";
+
+            await VerifyCSharpDiagnosticAsync(testCode, DiagnosticResult.EmptyDiagnosticResults, CancellationToken.None).ConfigureAwait(false);
+        }
+
         /// <summary>
         /// Verify that declaring a null reference type works for arrays.
         /// </summary>

documentation/SA1011.md

@@ -31,7 +31,9 @@ A closing square bracket should be followed by whitespace unless:
 * It is followed by a comma or semicolon
 * It is followed by a string interpolation alignment component. For example: `$"{x[i]:C}"`
 * It is followed by a string interpolation formatting component. For example: `$"{x[i],3}"`
-* It is followed by certain types of operator symbols.
+* It is followed by certain types of operator symbols
+* It is followed by a nullable reference type annotation for arrays (for example, `string[]? items`)
+* It is followed by the null-forgiving operator applied to an array or element access (for example, `values[0]!`)
 
 ## How to fix violations