Dena.CodeAnalysis.Testing 1.0.0

Dena.CodeAnalysis.Testing

This library provides TDD friendly DiagnosticAnalyzer test helpers:

• DiagnosticAnalyzerRunner

  A runner for Microsoft.CodeAnalysis.Diagnostics.DiagnosticAnalyzer. The purpose of the runner is providing another runner instead of Microsoft.CodeAnalysis.Analyzer.Testing.AnalyzerVerifier.VerifyAnalyzerAsync.

  Because of the AnalyzerVerifier has several problems:

  1. Using AnalyzerVerifier, it is hard to instantiate analyzer with custom arguments (the custom args may be needed if your analyzer is composed by several smaller analyzer-like components)
  2. AnalyzerVerifier may throw some exceptions because it test Diagnostics. But it should be optional because analyzer-like smaller components may not need it. If it is not optional the tests for the components become to need to wrap try-catch statements for each call of VerifyAnalyzerAsync

• Test Doubles for DiagnosticAnalyzer

  • NullAnalyzer: it do nothing
  • StubAnalyzer: it analyze codes with a Dena.CodeAnalysis.Testing.AnalyzerActions
  • SpyAnalyzer: it analyze codes and do not report any Diagnostics, but instead it records all actions that registered via Microsoft.CodeAnalysis.Dignostics.AnalysisContext

Requirements

• .NET Standard 2.1 or later

Usage

Run DiagnosticAnalyzer

var analyzer = new YourAnalyzer();

// The analyzer get intialized and get to call registered actions.
await DiagnosticAnalyzerRunner.Run(
    analyzer,
    @"public static class Foo
{
    public static void Bar()
    {
        System.Console.WriteLine(""Hello, World!"");
    }
}");

Get Diagnostics

var analyzer = new YourAnalyzer();

var diagnostics = await DiagnosticAnalyzerRunner.Run(
    analyzer,
    @"public static class Foo
{
    public static void Bar()
    {
        System.Console.WriteLine(""Hello, World!"");
    }
}");

Assert.AreEqual(0, diagnostics.Length);

Assert Locations

var location = diagnostic.Location;

LocationAssert.HaveTheSpan(
    "/0/Test0.",             // Optional. Skip path assertion if the path not specified,  
    new LinePosition(1, 0),
    new LinePosition(8, 5),
    location
);

Print Diagnostics

var diagnostics = await DiagnosticAnalyzerRunner.Run(
    anyAnalyzer,
    @"
internal static class Foo
{
    internal static void Bar()
    {
        System.Console.WriteLine(""Hello, World!"");
    }
}
ERROR");

Assert.AreEqual(0, diagnostics.Length, DiagnosticsFormatter.Format(diagnostics));
// This message is like:
//
//   // /0/Test0.cs(9,1): error CS0116: A namespace cannot directly contain members such as fields or methods
//   DiagnosticResult.CompilerError(""CS0116"").WithSpan(""/0/Test0.cs"", 9, 1, 9, 6),

Check whether the DiagnosticAnalyzer.Initialize have been called

var spyAnalyzer = new SpyAnalyzer();

var diagnostics = await DiagnosticAnalyzerRunner.Run(
    spyAnalyzer,
    @"public static class Foo
{
    public static void Bar()
    {
        System.Console.WriteLine(""Hello, World!"");
    }
}");

Assert.IsTrue(spyAnalyzer.IsInitialized);

Check recorded actions

var spyAnalyzer = new SpyAnalyzer();

var diagnostics = await DiagnosticAnalyzerRunner.Run(
    spyAnalyzer,
    @"public static class Foo
{
    public static void Bar()
    {
        System.Console.WriteLine(""Hello, World!"");
    }
}");

// CompilationActionHistory hold the Compilation object that given
// to the action registered by AnalysisContext.RegisterCompilationAction.
Assert.AreEqual(1, spyAnalyzer.CompilationActionHistory.Count);

// Other available histories are:
//
//   - spyAnalyzer.CodeBlockActionHistory
//   - spyAnalyzer.CodeBlockStartActionHistory
//   - spyAnalyzer.CompilationActionHistory
//   - spyAnalyzer.CompilationStartActionHistory
//   - spyAnalyzer.OperationActionHistory
//   - spyAnalyzer.OperationBlockActionHistory
//   - spyAnalyzer.OperationBlockStartAction
//   - spyAnalyzer.OperationBlockStartActionHistory
//   - spyAnalyzer.SemanticModelActionHistory
//   - spyAnalyzer.SymbolActionHistory
//   - spyAnalyzer.SymbolStartActionHistory
//   - spyAnalyzer.SyntaxNodeActionHistory
//   - spyAnalyzer.SyntaxTreeActionHistory

Do something in action

var stubAnalyzer = new StubAnalyzer(
    new AnalyzerActions
    {
        CodeBlockStartAction = context => DoSomething()
    }
);

await DiagnosticAnalyzerRunner.Run(
    stubAnalyzer,
    @"public static class Foo
{
    public static void Bar()
    {
        System.Console.WriteLine(""Hello, World!"");
    }
}");

// Other available actions are:
//
//   - stubAnalyzer.CodeBlockAction
//   - stubAnalyzer.CodeBlockStartAction
//   - stubAnalyzer.CompilationAction
//   - stubAnalyzer.CompilationStartAction
//   - stubAnalyzer.OperationAction
//   - stubAnalyzer.OperationBlockAction
//   - stubAnalyzer.OperationBlockStartAction
//   - stubAnalyzer.OperationBlockStartAction
//   - stubAnalyzer.SemanticModelAction
//   - stubAnalyzer.SymbolAction
//   - stubAnalyzer.SymbolStartAction
//   - stubAnalyzer.SyntaxNodeAction
//   - stubAnalyzer.SyntaxTreeAction

License

MIT license