BeSealed() always returns true in Testing

[yulivee]

Hi, I am trying to test class constraints with ArchUnit and noticed that BeSealed() always seem to return a positive test, regardless of the actual class configuration.

This testcase should never be green, but is:

var commandsWithoutResult = Classes().That().ImplementAnyInterfaces(_commandInterfaceWithoutResult);

        var commandsSealedRule = commandsWithoutResult.Should().BeSealed();
        var commandsNotSealedRule = commandsWithoutResult.Should().NotBeSealed();
        var rules = commandsSealedRule
            .And(commandsNotSealedRule);
        rulesCheck(Setup.Architecture);

I have a class matching the condition of commandsWithoutResult, and when I get the object via GetObjects and check for IsSealed manually, the Test correctly states, that my class is not sealed:

        var objects = commandsWithoutResult.GetObjects(Setup.Architecture).ToArray();
        objects.Should().AllSatisfy(o => o.IsSealed.Should().BeTrue());

In my Debugger, I see the IsSealed Property is set to false

Looking at the Sourcecode of BeSealed, I wonder whether the test just checks if the nullable value bool? IsSealed is set or not.

  public static ICondition<Class> BeSealed()
        {
            return new SimpleCondition<Class>(
                cls => !cls.IsSealed.HasValue || cls.IsSealed.Value,
                "be sealed",
                "is not sealed"
            );
        }

I feel like it should be !cls.IsSealed.HasValue && cls.IsSealed.Value == false. On the other hand, the definition of BeRecord() is the same and the BeRecord()-Test does not show this behaviour. So I am not exactly shure what is going on here.

Some willing to look into this?

[yulivee]

just realised, that this issue only arises if I concatenate rules:

var commandsWithoutResult = Classes().That().ImplementAnyInterfaces(_commandInterfaceWithoutResult);

        var commandsWithoutResultSealedRule = commandsWithoutResult.Should().BeSealed();
        var rulesWithoutResult = commandsWithoutResultSealedRule;
        // this works as expected
        rulesWithoutResult.Check(Setup.Architecture);

        var commandsWithoutResultPublicRule = commandsWithoutResult.Should().BePublic();
        var commandsWithoutResultRecordRule = commandsWithoutResult.Should().BeRecord();
        var commandsWithoutResultNamingRule = commandsWithoutResult.Should().HaveNameContaining("Command");
       
       // this always returns true, no matter if the sealed keyword is present or not
        var rulesWithoutResult2 = commandsWithoutResultSealedRule.And(commandsWithoutResultPublicRule).And(commandsWithoutResultRecordRule).And(commandsWithoutResultNamingRule);
        rulesWithoutResult2.Check(Setup.Architecture);

[yulivee]

I just realised via debugging, that you should not write this kind of pattern:

var commandsWithoutResult = Classes().That().ImplementAnyInterfaces(_commandInterfaceWithoutResult);

        var commandsSealedRule = commandsWithoutResult.Should().BeSealed();
        var commandsNotSealedRule = commandsWithoutResult.Should().NotBeSealed();

The commandsNotSealedRule overwrites the Rule defined by commandsSealedRule. You are not supposed to reuse definitions by saving them in variables.

Rewriting my test like this:

var commandsRule = Classes().That().ImplementAnyInterfaces(_commandInterfaceWithoutResult).
.Should().BeSealed()
.AndShould().NotBeSealed();

ALWAYS Fails the test. Also the weird Issues when concatenating rules went away.

Wished that it was a little clearer from the documentation how you are supposed to write these rules. That was kind of unexpected.

[alexanderlinne]

Hi @yulivee, yes, ArchUnitNET currently uses a stateful builder object for the fluent syntax. Since C# has no notion of move semantics we can currently not enforce correct usage here. I actually currently attempt re-implementing the fluent syntax interface using immutable expression objects. Then reusing partial expressions would be possible.