Convert to Switch Save Action improper use #2370

[mebigfatguy]

Using Eclipse
Version: 2025-12 (4.38.0)
Build id: 20251204-0850

With jdk 21 (altho targetting jdk17)

on Linux Mint 22
This class

package eclipsesaveactions;

import java.util.Arrays;
import java.util.Collections;
import java.util.List;

public class SaveActionsBug {

enum GiantSounds {Fee, Fi, Fo, Fum};

public List<String> convertToSwitchIssue(GiantSounds gs) {
    String key;
    switch (gs) {
        case Fee: 
            key = "Oh My";
        break;
        
        case Fi: 
            key = "Wow";
        break;
        
        case Fo: 
            key = "Uh oh";
        break;
        
        default: return Collections.emptyList();
    }
    
    return Arrays.asList("Yikes", key);
}
}

When convert to switch expressions is turned on and you auto save converts to

package eclipsesaveactions;

import java.util.Arrays;
import java.util.Collections;
import java.util.List;

public class SaveActionsBug {

enum GiantSounds {
    Fee,
    Fi,
    Fo,
    Fum
}

public List<String> convertToSwitchIssue(GiantSounds gs) {
    String key;
    key = switch (gs) {
        case Fee -> key = "Oh My";
        case Fi -> key = "Wow";
        case Fo -> key = "Uh oh";
        default -> {
            return Collections.emptyList();
        }
    };
    return Arrays.asList("Yikes", key);
}
}

which is incorrect.