Fix S2589 FP: || and property patterns

[jnyrup]

Description

While rewriting some older code to using pattern matching it triggered S2589 when using || together with a property pattern.

obj is A { Value: true } || obj is B { Value: true };

When rewriting the disjunction with a logical pattern using or S2589 disappeared despite both lowered and compiled code are identical.

obj is A { Value: true } or B { Value: true };

Repro steps

public interface I { }

public class A : I { }

public class B : I { }

class C
{
    public bool Foo(I obj) => obj is A { } || obj is B { }; // Triggers S2589 on "obj is B { }"

    public bool Bar(I obj) => obj is A || obj is B; // No warnings

    public bool Baz(I obj) => obj is A { } or B { }; // No warnings
}

Expected behavior

S2589 is not triggered for Foo

Actual behavior

S2589 is triggered for Foo.

Known workarounds

Rewrite Foo to Baz.

Related information

• C#/VB.NET Plugins version: SonarLint for Visual Studio 2022 6.15.0.67199
• Visual Studio version: 2022 17.6.0 Preview 3.0
• MSBuild / dotnet version: .NET 6
• SonarScanner for .NET version (if used)
• Operating System: Windows 10

[pavel-mikula-sonarsource]

Hi @jnyrup,

Thank you for reporting this case. I confirm it as FP. We plan to reimplement the rule soon and that should address the problem.

[mary-georgiou-sonarsource]

Fixed by #7750