Description Fabrice Tiercelin 2020-11-22 03:31:06 EST

Given:
private void myMethod() {
  methodWithUunusedParam(123);
}

private void methodWithUunusedParam(int unused) {
}

When:
Clicking on "Remove 'unused', keep assignments with side effects"

Then:
private void myMethod() {
  methodWithUunusedParam(123);
                         ^^^
}

private void methodWithUunusedParam() {
}

Compilation error.


When a method parameter (let's name it 'x') is not used in the method body, there is the warning "The value of the parameter x is not used". 5 quickfixes are available. The first one is "Remove 'x', keep assignments with side effects". If you click on the quickfix, the parameter is removed on the method signature but the method calls are not updated. In other words, the values passed as the parameter are still passed and the signature of the call becomes wrong.

Currently, if a user wants to use this quickfix, the user should rather right-click on the method, click on Refactor -> Change the Method Signature... -> Select the parameter, click on remove and click on OK. Doing so, so behavior is correct.

The quickfix should do the same. It should refactor the whole project. It seems that the code should be edited here:
https://git.eclipse.org/c/jdt/eclipse.jdt.ui.git/tree/org.eclipse.jdt.core.manipulation/core%20extension/org/eclipse/jdt/internal/corext/fix/UnusedCodeFixCore.java?id=c63ac951840bb1149dd72111d963b0129d9df235#n225