Add some unit tests

Author: menees

src/Menees.Analyzers/Men019SupportAsyncCancellationToken.cs

@@ -3,7 +3,6 @@
 using System;
 using System.Collections.Generic;
 using System.Diagnostics.CodeAnalysis;
-using System.Text;
 using Microsoft.CodeAnalysis;
 
 [DiagnosticAnalyzer(LanguageNames.CSharp)]

tests/Menees.Analyzers.Test/Men019UnitTests.cs

@@ -0,0 +1,95 @@
+namespace Menees.Analyzers.Test;
+
+using Microsoft.CodeAnalysis.CodeFixes;
+
+[TestClass]
+public class Men019UnitTests : CodeFixVerifier
+{
+	#region Protected Properties
+
+	protected override DiagnosticAnalyzer CSharpDiagnosticAnalyzer => new Men019SupportAsyncCancellationToken();
+
+	#endregion
+
+	#region ValidCodeTest
+
+	[TestMethod]
+	public void ValidCodeTest()
+	{
+		this.VerifyCSharpDiagnostic(string.Empty);
+
+		const string test = @"
+using System.Threading;
+using System.Threading.Tasks;
+
+#pragma warning disable MEN019 // We have to make some 'invalid' interface methods inheritable.
+public interface IThink1 { Task Think1(); }
+public interface IThink2 { Task Think2(); }
+#pragma warning restore MEN019
+
+public sealed class Cancellable { public CancellationToken Cancel {get;}}
+public sealed class TestBase : IThink1
+{
+	public virtual Task Think1() => return Task.CompletedTask;
+}
+
+public class Test : IFormattable, IThink2
+{
+	private Task<bool> CheckPrivate(CancellationToken c) { return Task.FromResult(true); }
+
+	public async Task UseAsyncKeyword(CancellationToken c) { await Task.Yield(); }
+
+	// Interface implementations
+	Task IThink2.Think2() => return Task.CompletedTask;
+	public string ToString(string? format, IFormatProvider? formatProvider) => ""test"";
+	public override Task Think1() => return Task.CompletedTask;
+
+	[TestMethod]
+	public Task UnitTest() => return Task.CompletedTask;
+
+	public Task GetsCancelProperty(Cancellable cancellable) => return Task.CompletedTask;
+}";
+
+		this.VerifyCSharpDiagnostic(test);
+	}
+
+	#endregion
+
+	#region InvalidCodeTest
+
+	[TestMethod]
+	public void InvalidCodeTest()
+	{
+		const string test = @"
+public class Test
+{
+	// todo: Add invalid methods
+	// (method.DeclaredAccessibility > Accessibility.Private || settings.CheckPrivateMethodsForCancellation)
+	// !method.IsImplicitlyDeclared
+	// IsAsyncMethodKindSupported(method.MethodKind)
+	// !method.ReturnsVoid
+	// method.ReturnType is not null  // Roslyn's ISymbolExtensions.IsAwaitableNonDynamic checks this
+	// (method.IsAsync || IsAwaitable(method.ReturnType))
+	// !method.IsOverride
+	// method.ExplicitInterfaceImplementations.IsDefaultOrEmpty
+	// !IsImplicitInterfaceImplementation(method)
+	// !settings.IsUnitTestMethod(method))
+	// !HasCancellationTokenParameter(parameters)
+	// !parameters.Any(ParameterHasCancellationTokenProperty)
+}";
+
+		// var analyzer = this.CSharpDiagnosticAnalyzer;
+		DiagnosticResult[] expected =
+		[
+			// new DiagnosticResult(analyzer)
+			// {
+				// Message = "The numeric literal 1000000 should use digit separators.",
+				// Locations = [new DiagnosticResultLocation("Test0.cs", 4, 30)]
+			// },
+		];
+
+		this.VerifyCSharpDiagnostic(test, expected);
+	}
+
+	#endregion
+}