False-positive java:S1128 unnecessary import

[tim-comline (Tim)]

Template for a good bug report, formatted with Markdown:

• versions used: SonarLint plugin (4.11.0.20867) with Intellij

(IntelliJ IDEA 2020.2.2 (Ultimate Edition)
Build #IU-202.7319.50, built on September 15, 2020
Runtime version: 11.0.8+10-b944.31 x86_64
VM: OpenJDK 64-Bit Server VM by JetBrains s.r.o.
macOS 10.15.7)

• error observed (wrap logs/code around triple quote ``` for proper formatting)

Remove this unused import 'com.cartrust.comregistraiton.organiozation.model.DocumentState.UPLOADED'

• steps to reproduce

It seem related to the enum value “UPLOADED” if I refactor the value to “UPLOADED_YEAH” the error disappears. Of course it was used after the refactoring too.

Other enum values from the same enum are not shown as errors:

import static com.cartrust.registration.organization.model.DocumentState.MISSING;
import static com.cartrust.registration.organization.model.DocumentState.UPLOADED;
import static com.cartrust.registration.organization.model.DocumentState.WAITING_FOR_NOTIFICATION;
import static com.cartrust.registration.organization.model.DocumentState.WAITING_FOR_UPLOAD;

Here’s the usage in the same file:

  @EventHandler
  public void on(DocumentAddedEvent event) {
    val aggregateId = event.getOwnerOrganizationId();

    organizationViewRepository.findById(aggregateId).ifPresent(
        organizationView -> {
          organizationViewRepository.save(organizationView.toBuilder()
                .businessRegistrationDocumentId(event.getDocumentId())
                .businessRegistrationState(UPLOADED)
                .build());         
        }
    );
  }

• potential workaround

Rename enum values “UPLOADED” to something else.

P.S.: use the #bug:fault sub-category if you’re hitting a specific crash/error , or the #bug:fp sub-category for rules-related behaviour

[Michael (Michael Gumowski)]

Hello @tim-comline,

Sorry for coming back to you so late after you posted this. Unfortunately, without a self-contained reproducer code, it will be hard for me to reproduce the issue on my side, as I can only assumes on what are the methods used in the code snippet. Can you simplify your code snippet and provide a code which which explicitly reproduce the issue without having to figure some methods?

Also, I guess that you are using lombok (val?), and we have always been facing issue handling it correctly in our analysis. It might be a track to explore.

Thanks,
Michael

[mlkammer (Marnix Kammer)]

We have a similar problem: false positives on statically imported constants. The following class is simplified and raises an issue on the statically imported OK constant:

package test;

import static io.netty.handler.codec.http.HttpResponseStatus.OK;

class MyHttpEndpoint {

    Object handleRequest(Object request) {
        // ... some request handling code that doesn't matter now

        return respond(OK);
    }

    private Object respond(Object status) {
        return status;
    }
}

Warning message:

Remove this unused import ‘io.netty.handler.codec.http.HttpResponseStatus.OK’.

This is on SonarCloud, so latest released version.

Is this enough to be able to reproduce / fix the problem?
Thank you in advance.

[mlkammer (Marnix Kammer)]

Hi @Michael, I just realized I didn’t tag you in the comment above. Could you take a look at it to see if it’s enough to reproduce the problem?

[Quentin (Quentin Jaquier)]

Hello @mlkammer

Coming back to you with good news about this topic: we identified a way to greatly improve the precision of this rule (see SONARJAVA-3777). Fixing this ticket will require a big refactoring of the implementation, I don’t think it is worth it to dig deeper into reproducing your issue at this point. And anyway, I’m quite confident this will make your issue go away.

Thanks for taking the time to report this false positive.
Best,
Quentin