Error parsing java file with switch + enum

SonarQube Plugin Development
, ,
1

Hello devs,

I have written a standalone program to detect and automatically resolve false positive sonar issues. (related to this thread.) It’s working fine, but the parser fails to parse some Java files.

Here is an example.

Java enum:

public enum Fruit {
    APPLE, BANANA
}

Java class:

public class Main {
    private String extracted(Fruit fruit) {
        return switch (fruit) {
            case BANANA -> "banana";
            case APPLE -> "apple";
        };
    }

    public static void main(String[] args) {
        File file = new File("/Path/To/This/Main.java");
        InputFile inputFile = new GeneratedFile(file.toPath());
        JavaAstScanner scanner = new JavaAstScanner(null);
        VisitorsBridge visitorsBridge = new VisitorsBridge(new SubscriptionVisitor() {
            @Override
            public List<Tree.Kind> nodesToVisit() {
                return List.of(Tree.Kind.METHOD);
            }
        });
        scanner.setVisitorBridge(visitorsBridge);
        scanner.scan(Collections.singleton(inputFile));
    }
}

This gives the following error.

Unable to parse source file : '/Path/To/This/Main.java'
com.sonar.sslr.api.RecognitionException: Parse error at line 05 column 23: A switch expression should have a default case

I guess the AST scanner cannot identify the switch case labels as enum values in this case. Therefore it expects a default case, which kind of makes sense. But I don’t want the parser to break due to this. Is there a way to tell the parser not to do this check while parsing?

I’m using the following libraries.

org.sonarsource.java:java-frontend:7.34.0.35958
org.sonarsource.api.plugin:sonar-plugin-api:10.7.0.2191

Thanks,
Bhathiya