[PiranhaJava] Does not not clean up properly after removing feature flag

The un-referenced methods inside the code Piranha cleaned up is not removed. I was hoping the code which is no more referenced after clean up (dummyMethod in below example) will also be removed and hence a deep cleanup.

Before:

  public void bar() {
    if (expt.flagDisabled(TestExperimentName.SAMPLE_STALE_FLAG)) {
      System.out.println("Hi World");
      dummyMethod();
    }
  }

  private void dummyMethod() {
    System.out.println("Dummy Method");
  }

After:

  public void bar() {
    
  }

  private void dummyMethod() {
    System.out.println("Dummy Method");
  }

[mkr-plse]

Other variants of Piranha (Swift, JS) have already implemented some form of deep cleaning. AFAIK, Proguard may be able to delete the deadcode from bytecode but not from source. We expect to add this feature to PiranhaJava. Unfortunately, we haven’t yet gotten to this milestone yet.

[mkr-plse]

@NikitashP We are working on making this much easier with a newer implementation of Piranha. See here. Please check it out as we expect it to be very customizable and adaptable for various use cases. cc @ketkarameya