ILSpy/ILSpy.Tests/Analyzers/Library/MethodUsesAnalyzerTests.cs

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using System.Linq;

using ICSharpCode.Decompiler.TypeSystem;
using ICSharpCode.ILSpyX;
using ICSharpCode.ILSpyX.Analyzers;
using ICSharpCode.ILSpyX.Analyzers.Builtin;

using ICSharpCode.ILSpy.Languages;

using NUnit.Framework;

namespace ICSharpCode.ILSpy.Tests.Analyzers.Library;

[TestFixture]
public class MethodUsesAnalyzerTests
{
	AssemblyList assemblyList = null!;
	CSharpLanguage language = null!;
	ICompilation testAssemblyTypeSystem = null!;
	ITypeDefinition typeDefinition = null!;

	[OneTimeSetUp]
	public void Setup()
	{
		assemblyList = new AssemblyList();
		var testAssembly = assemblyList.OpenAssembly(typeof(MethodUsesAnalyzerTests).Assembly.Location);
		assemblyList.OpenAssembly(typeof(void).Assembly.Location);
		testAssemblyTypeSystem = testAssembly.GetTypeSystemOrNull()!;
		language = new CSharpLanguage();
		typeDefinition = testAssemblyTypeSystem
			.FindType(typeof(TestCases.Main.MainAssembly))
			.GetDefinition()!;
	}

	[Test]
	public void MainAssemblyUsesSystemStringEmpty()
	{
		var context = new AnalyzerContext { AssemblyList = assemblyList, Language = language };
		var symbol = typeDefinition.Methods.First(m => m.Name == "UsesSystemStringEmpty");

		var results = new MethodUsesAnalyzer().Analyze(symbol, context).ToList();

		Assert.That(results.Count == 1);
		var field = results.Single() as IField;
		Assert.That(field, Is.Not.Null);
		Assert.That(!field!.MetadataToken.IsNil);
		Assert.That("System.String.Empty", Is.EqualTo(field.FullName));
	}
}