SomeRecipeTest.java

package org.yourorg.starter;

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

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

public class SomeRecipeTest implements RewriteTest {

    @Override
    public void defaults(RecipeSpec spec) {
        spec.recipe(new SomeRecipe());
    }

    @Test
    void example() {
        rewriteRun(
          //language=java
          java("""
                package org.openrewrite;
                
                import java.util.ArrayList;
                import java.util.List;
                import java.util.stream.Collectors;
                
                @AnAnnotation
                public class A {
                
                    List<Integer> a = new ArrayList<>();
                
                    int foo() {
                        int a = 1 + 2, b = 3, c;
                        this.a = this.a.stream()
                                .map(it -> it + 1)
                                .collect(Collectors.toList());
                        return a;
                    }
                }
                
                @interface AnAnnotation {}
                """)
        );
    }
}