Layered architecture ignores violations in type parameters

[stefanroeck]

Given:

• A layered architecture with 2 packages "presentation" and "shared"
• presentation might access shared but not vice versa
• class in shared references class in presentation as type parameter of java.util.list

Expected:

• Error because of layered architecture violation

Actual:

• No error.

package com.archunitbug.presentation;
public class ExceptionDetails {}

package com.archunitbug.shared;
import java.util.List;
import com.archunitbug.presentation.ExceptionDetails;

public class ExceptionWithBackReference extends RuntimeException {
    private List<ExceptionDetails> details;
    public ExceptionWithBackReference(List<ExceptionDetails> details) {
        this.details = details;
    }
}

Test:

import static com.tngtech.archunit.library.Architectures.layeredArchitecture;
import org.junit.Test;
import com.tngtech.archunit.core.domain.JavaClasses;
import com.tngtech.archunit.core.importer.ClassFileImporter;
import com.tngtech.archunit.core.importer.ImportOption;
import com.tngtech.archunit.core.importer.ImportOptions;
import com.tngtech.archunit.library.Architectures.LayeredArchitecture;
public class ArchunitLayersException {
    @Test
    public void enforceAllNcrLayersTopDown() {
        JavaClasses classes = new ClassFileImporter(new ImportOptions().with(ImportOption.Predefined.DONT_INCLUDE_TESTS)).importPackages("com.archunitbug");
        LayeredArchitecture rule = layeredArchitecture() //
                .layer("presentation").definedBy("com.archunitbug.presentation") //
                .layer("shared").definedBy("com.archunitbug.shared") //
                .whereLayer("presentation").mayNotBeAccessedByAnyLayer()//
                .whereLayer("shared").mayOnlyBeAccessedByLayers("presentation");

        rule.check(classes);
    }
}

[hankem]

I believe that ArchUnit (in its current version 0.9.3) does not yet handle type parameters, cf. #115.

If ExceptionWithBackReference had an ExceptionDetails field instead of List<ExceptionDetails>, your LayeredArchitecture test would fail as expected.

[codecholeric]

Yes, this is correct, the current version cannot detect this, since ArchUnit only sees a raw reference to java.util.List. As soon as #115 is done, dependencies of a JavaClass can be extended with type parameters and this violation will then be detected.