hellbrick / nocapture Goto Github PK

using System;
using System.Collections.Generic;
using System.Linq;
using HellBrick;

class X
{
  public void Test([NoCapture]Func<List<int>, int, IEnumerable<int>> f) { }

  public void FalseNegative()
    => Test(
      (list, v) => list.Select(x => x + v)
    );
}

		[Fact]
		public void CapturingArgumentPassedToNoCaptureParamsItemIsReported()
			=> _verifier
			.Source
			(
@"
using System;

[AttributeUsage( AttributeTargets.Parameter | AttributeTargets.Method )]
class NoCaptureAttribute : Attribute
{
}

class C
{
	private readonly int _field = 42;

	void CallSite() => Invoke( 64, x => x + 2, x => _field + x );
	T Invoke<T>( T initialValue, [NoCapture] params Func<T, T>[] transforms ) => initialValue;
}
"
			)
			.ShouldHaveDiagnostic( "Invoke", "transforms", "this" );

		[Fact]
		public void NoFalsePositiveForNonCapturingLambdaInsideLocalMethod()
			=> _verifier
			.Source
			(
@"
using System;
using System.Collections.Generic;
using System.Linq;

[AttributeUsage( AttributeTargets.Parameter | AttributeTargets.Method )]
class NoCaptureAttribute : Attribute
{
}

class C
{
	private readonly int[] _numbers = { 42, 64, 128 };

	public IEnumerable<int> EnumerateNumbers()
	{
		return
			_numbers == null
			? Enumerable.Empty<int>()
			: EnumerateWithoutValidation();

		IEnumerable<int> EnumerateWithoutValidation()
			=> _numbers
			.WhereNoCapture( x => x == 42 );
	}
}

static class X
{
		public static IEnumerable<T> WhereNoCapture<T>( this IEnumerable<T> sequence, [NoCapture] Func<T, bool> predicate )
			=> sequence.Where( predicate );
}
"
			)
			.ShouldHaveNoDiagnostics();