SimplifyConstantIfBranchExecution leaves unreachable code

[lambm]

What version of OpenRewrite are you using?

I am using

• org.openrewrite.recipe:rewrite-static-analysis:1.20.0
• org.openrewrite.recipe:rewrite-recipe-bom:2.22.0

How are you running OpenRewrite?

Java test case

import org.junit.jupiter.api.Test;
import org.openrewrite.staticanalysis.SimplifyConstantIfBranchExecution;
import org.openrewrite.test.RewriteTest;

import static org.openrewrite.java.Assertions.java;

class SimplifyTest implements RewriteTest {

    @Test
    void test() {
        rewriteRun(
                spec -> spec.recipe(new SimplifyConstantIfBranchExecution()),
                //language=java
                java(
                        """
                            public class A {
                                public boolean test() {
                                    if (true) {
                                        Object x;
                                        return true;
                                    }
                                    return false;
                                }
                            }
                        """,
                        """
                             public class A {
                                 public boolean test() {
                                     Object x;
                                     return true;
                                 }
                             }
                         """
                )
        );
    }
}

What is the smallest, simplest way to reproduce the problem?

public class A {
    public boolean test() {
        if (true) {
            Object x;
            return true;
        }
        return false;
    }
  }

What did you expect to see?

public class A {
     public boolean test() {
         Object x;
         return true;
     }
 }

What did you see instead?

public class A {
     public boolean test() {
         {
            Object x;
            return true;
         }
         return false;
     }
 }

What is the full stack trace of any errors you encountered?

No error, just invalid output.

Are you interested in contributing a fix to OpenRewrite?

Unable to contribute.

[timtebeek]

Thanks for the feedback @lambm ! Great to see that as a runnable example. Indeed a missed case, and would then negatively affect recipes that rely on this too, like rewrite-feature-flags. Appreciate that you're unable to contribute but still wanted to report the issue; I hope in practice at least it was rare? We'll add it to the backlog and hope to get to it soon-ish.

[AHB102]

@timtebeek @lambm I'd like to contribute, but I'm a bit unclear on the direction. Can you provide more details?😅

[timtebeek]

Appreciate the offer to help here @AHB102 ; be sure to read our contributing guidelines. From there fork and check out this project, add the above unit test to SimplifyConstantIfBranchExecutionTest.java and try to make it pass. In this case: if the if block directly contains a return statement, then we can remove any else or following statements.

[AHB102]

@timtebeek Great! I'll start integrating this and reach out if I have any questions. 😁