[UnconditionalSuppressMessage] Add missing using if needed

MemoryAnalyzers/MemoryAnalyzers.CodeFixes/Extensions.cs

@@ -0,0 +1,39 @@
+using System.Collections.Immutable;
+using System.Linq;
+using Microsoft.CodeAnalysis.CSharp;
+using Microsoft.CodeAnalysis.CSharp.Syntax;
+
+namespace MemoryAnalyzers;
+
+static class Extensions
+{
+	// https://github.com/protobuf-net/protobuf-net/blob/ae84aba11942eb45d261316a966c811bac8565b3/src/protobuf-net.BuildTools/Internal/Roslyn/Extensions/CompilationUnitSyntaxExtensions.cs
+	public static CompilationUnitSyntax AddUsingsIfNotExist(
+		this CompilationUnitSyntax compilationUnitSyntax,
+		params string[]? usingDirectiveNames)
+	{
+		if (usingDirectiveNames is null || usingDirectiveNames.Length == 0)
+			return compilationUnitSyntax;
+
+		// build a hashset for efficient lookup
+		// comparison is done based on string value, because different usings can have different types of identifiers:
+		// - IdentifierName
+		// - QualifiedNameSyntax
+		var existingUsingDirectiveNames = compilationUnitSyntax.Usings
+			.Select(x => x.Name?.ToString().Trim())
+			.ToImmutableHashSet();
+
+		foreach (var directive in usingDirectiveNames)
+		{
+			var directiveTrimmed = directive.Trim();
+			if (!existingUsingDirectiveNames.Contains(directiveTrimmed))
+			{
+				compilationUnitSyntax = compilationUnitSyntax.AddUsings(
+					SyntaxFactory.UsingDirective(
+						SyntaxFactory.ParseName(" " + directiveTrimmed)));
+			}
+		}
+
+		return compilationUnitSyntax;
+	}
+}

MemoryAnalyzers/MemoryAnalyzers.CodeFixes/MemoryAnalyzersCodeFixProvider.cs

@@ -106,9 +106,14 @@ async Task<Solution> RemoveMember(Document document, SyntaxNode node, Cancellati
 		async Task<Solution> AddUnconditionalSuppressMessage(Diagnostic diagnostic, Document document, MemberDeclarationSyntax member, CancellationToken cancellationToken)
 		{
 			var root = await document.GetSyntaxRootAsync(cancellationToken);
-			if (root is null || member.Parent is null)
+			if (root is null)
 				return document.Project.Solution;
 
+			if (root is CompilationUnitSyntax unit)
+			{
+				root = unit.AddUsingsIfNotExist("System.Diagnostics.CodeAnalysis");
+			}
+
 			// Used: http://roslynquoter.azurewebsites.net/
 			var attributes = member.AttributeLists.Add(
 				AttributeList(SingletonSeparatedList(

MemoryAnalyzers/MemoryAnalyzers.Test/CodeFixUnitTests.cs

@@ -41,6 +41,8 @@ class Foo : NSObject
 			""";
 
 			var codefix = """
+			using System.Diagnostics.CodeAnalysis;
+
 			class Foo : NSObject
 			{
 			    [UnconditionalSuppressMessage("Memory", "MA0001", Justification = "Proven safe in test: XYZ")]
@@ -49,7 +51,7 @@ class Foo : NSObject
 			""";
 
 			var expected = VerifyCS.Diagnostic("MA0001").WithLocation(0).WithArguments("EventName");
-			await VerifyCS.VerifyCodeFixAsync(test, expected, codefix, index: 1);
+			await VerifyCS.VerifyCodeFixAsync(test, expected, codefix, index: 1, iterations: 2);
 		}
 
 		[TestMethod]
@@ -84,6 +86,8 @@ class Foo : NSObject
 			""";
 
 			var codefix = """
+			using System.Diagnostics.CodeAnalysis;
+
 			class Foo : NSObject
 			{
 			    [UnconditionalSuppressMessage("Memory", "MA0002", Justification = "Proven safe in test: XYZ")]
@@ -92,7 +96,7 @@ class Foo : NSObject
 			""";
 
 			var expected = VerifyCS.Diagnostic("MA0002").WithLocation(0).WithArguments("FieldName");
-			await VerifyCS.VerifyCodeFixAsync(test, expected, codefix, index: 1);
+			await VerifyCS.VerifyCodeFixAsync(test, expected, codefix, index: 1, iterations: 2);
 		}
 
 		[TestMethod]
@@ -141,6 +145,8 @@ class Foo : NSObject
 		public async Task MA0003_Remove()
 		{
 			var test = """
+			using System.Diagnostics.CodeAnalysis;
+
 			[Register("UITextField", true)]
 			class UITextField
 			{
@@ -162,6 +168,8 @@ void OnEditingDidBegin(object sender, EventArgs e)
 			""";
 
 			var codefix = """
+			using System.Diagnostics.CodeAnalysis;
+
 			[Register("UITextField", true)]
 			class UITextField
 			{
@@ -190,6 +198,8 @@ void OnEditingDidBegin(object sender, EventArgs e)
 		public async Task MA0003_MakeStatic()
 		{
 			var test = """
+			using System.Diagnostics.CodeAnalysis;
+
 			[Register("UITextField", true)]
 			class UITextField
 			{
@@ -211,6 +221,8 @@ void OnEditingDidBegin(object sender, EventArgs e)
 			""";
 
 			var codefix = """
+			using System.Diagnostics.CodeAnalysis;
+
 			[Register("UITextField", true)]
 			class UITextField
 			{

MemoryAnalyzers/MemoryAnalyzers.Test/Verifiers/CSharpCodeFixVerifier`2.cs

@@ -35,6 +35,9 @@ public static async Task VerifyAnalyzerAsync(string source, params DiagnosticRes
 
 			AddTestCode(test.TestState);
 
+			// Intentionally left out of codefix tests
+			test.TestState.Sources.Add("global using System.Diagnostics.CodeAnalysis;");
+
 			test.ExpectedDiagnostics.AddRange(expected);
 			await test.RunAsync(CancellationToken.None);
 		}
@@ -44,17 +47,21 @@ public static async Task VerifyCodeFixAsync(string source, string fixedSource, i
 			=> await VerifyCodeFixAsync(source, DiagnosticResult.EmptyDiagnosticResults, fixedSource, index);
 
 		/// <inheritdoc cref="CodeFixVerifier{TAnalyzer, TCodeFix, TTest, TVerifier}.VerifyCodeFixAsync(string, DiagnosticResult, string)"/>
-		public static async Task VerifyCodeFixAsync(string source, DiagnosticResult expected, string fixedSource, int index)
-			=> await VerifyCodeFixAsync(source, new[] { expected }, fixedSource, index);
+		public static async Task VerifyCodeFixAsync(string source, DiagnosticResult expected, string fixedSource, int index, int iterations = 1)
+			=> await VerifyCodeFixAsync(source, new[] { expected }, fixedSource, index, iterations);
 
 		/// <inheritdoc cref="CodeFixVerifier{TAnalyzer, TCodeFix, TTest, TVerifier}.VerifyCodeFixAsync(string, DiagnosticResult[], string)"/>
-		public static async Task VerifyCodeFixAsync(string source, DiagnosticResult[] expected, string fixedSource, int index)
+		public static async Task VerifyCodeFixAsync(string source, DiagnosticResult[] expected, string fixedSource, int index, int iterations = 1)
 		{
 			var test = new Test
 			{
 				TestCode = source,
 				FixedCode = fixedSource,
 				CodeActionIndex = index,
+				NumberOfIncrementalIterations = iterations,
+				NumberOfFixAllInDocumentIterations = iterations,
+				NumberOfFixAllInProjectIterations = iterations,
+				NumberOfFixAllIterations = iterations,
 			};
 
 			AddTestCode(test.TestState);
@@ -68,7 +75,6 @@ static void AddTestCode(SolutionState testState)
 		{
 			// Global usings
 			testState.Sources.Add("global using System;");
-			testState.Sources.Add("global using System.Diagnostics.CodeAnalysis;");
 			testState.Sources.Add("global using Foundation;");
 			testState.Sources.Add("global using UIKit;");
 

MemoryAnalyzers/MemoryAnalyzers/MemoryAnalyzer.cs

@@ -199,6 +199,7 @@ static bool IsDelegateType(INamedTypeSymbol type)
 
 			return IsDelegateType(baseType);
 		}
+
 		static bool IsObject(INamedTypeSymbol type) =>
 			type.ContainingNamespace.Name == "System" && type.Name == "Object";