openrewrite / openrewrite/rewrite

Parse error in Java parser when using type annotation with varags

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bug java parser
Dominant language
Java
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Merged PRs (30d)
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Description

Used version

rewrite-java 8.56.1

The gist

Object @Nullable ... other is interpreted as Object @Nullable[] ... other

while e.g. the following is interpreted correctly:
Object @Nullable[] ... other
Object ... other

Issue fully replicated in test:

package de.domagoj.or.test;

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

import org.junit.jupiter.api.Test;
import org.openrewrite.java.JavaParser;
import org.openrewrite.test.RecipeSpec;
import org.openrewrite.test.RewriteTest;

public class MyTest implements RewriteTest {
        @Test
        void shouldParse() {
            rewriteRun(
                java(
                    """
package de.domagoj.or.test.example;

import static java.lang.annotation.ElementType.TYPE_USE;

import java.lang.annotation.Documented;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

public interface Itf {
    @Documented
    @Retention(RetentionPolicy.CLASS)
    @Target({ TYPE_USE })
    public @interface NonNull {
    }
    @Documented
    @Retention(RetentionPolicy.CLASS)
    @Target({ TYPE_USE })
    public @interface Nullable {
    }


    @NonNull
    Object exampleMethod(@NonNull Object @Nullable ... other);
}
                    """
                )
            );
        }

}

Contributor guide

Open the contributing guide

First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

Research direction

Start with the embedded rewriteRun JavaParser reproduction and inspect how the parser handles a type-use annotation before a varargs parameter. Confirm the distinction between Object @Nullable ... other and Object @Nullable[] ... other; done means the supplied test parses the first form without interpreting it as an array annotation.

Written by the indexing model from the issue text.

Assessment

Tech stack
java
Domain
compilers
Issue type
Bug
Difficulty
3/5
Estimated time
1-2 days
Activity status
Stale
Clarity
Clearly specified
Newbie friendliness
52/100

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