MapStruct <> Lombok boolean property with `is` in the name issue

BuggyTestMapperImpl.java

// The mapper generated by MapStruct without fixes (commented out code)
package com.transferwise.swiftprocessor.mapper.event;

import javax.annotation.processing.Generated;

@Generated(
    value = "org.mapstruct.ap.MappingProcessor",
    date = "2024-01-17T22:06:57+0000",
    comments = "version: 1.5.3.Final, compiler: IncrementalProcessingEnvironment from gradle-language-java-7.4.2.jar, environment: Java 17.0.9 (Azul Systems, Inc.)"
)
public class TestMapperImpl implements TestMapper {

    @Override
    public LombokTest fromNonLombok(NonLombokTest test) {
        if ( test == null ) {
            return null;
        }

        LombokTest.LombokTestBuilder lombokTest = LombokTest.builder();

        lombokTest.valid( test.isValid() );
        lombokTest.isGood( test.isIsGood() );

        return lombokTest.build();
    }

    @Override
    public NonLombokTest fromLombok(LombokTest test) {
        if ( test == null ) {
            return null;
        }

        boolean isGood = false;
        boolean valid = false;

        isGood = test.isGood();
        valid = test.isValid();

        NonLombokTest nonLombokTest = new NonLombokTest( valid, isGood );

        return nonLombokTest;
    }
}

FixedTestMapperImpl.java

// The mapper generated by MapStruct with fixes (commented out code uncommented)
package com.transferwise.swiftprocessor.mapper.event;

import javax.annotation.processing.Generated;

@Generated(
    value = "org.mapstruct.ap.MappingProcessor",
    date = "2024-01-17T22:12:48+0000",
    comments = "version: 1.5.3.Final, compiler: IncrementalProcessingEnvironment from gradle-language-java-7.4.2.jar, environment: Java 17.0.9 (Azul Systems, Inc.)"
)
public class TestMapperImpl implements TestMapper {

    @Override
    public LombokTest fromNonLombok(NonLombokTest test) {
        if ( test == null ) {
            return null;
        }

        LombokTest.LombokTestBuilder lombokTest = LombokTest.builder();

        lombokTest.valid( test.isValid() );
        lombokTest.isGood( test.isIsGood() ); // Notice isIsGood being used here

        return lombokTest.build();
    }

    @Override
    public NonLombokTest fromLombok(LombokTest test) {
        if ( test == null ) {
            return null;
        }

        boolean isGood = false;
        boolean valid = false;

        isGood = test.isGood(); // Notice isGood being used here, since we mapped our source property to be just `good`
        valid = test.isValid();

        NonLombokTest nonLombokTest = new NonLombokTest( valid, isGood );

        return nonLombokTest;
    }
}

TestMapper.java

package com.transferwise.swiftprocessor.mapper.event;

import lombok.AllArgsConstructor;
import lombok.Builder;
import lombok.Data;
import org.mapstruct.Mapper;
import org.mapstruct.Mapping;

@Data
@Builder
@AllArgsConstructor
class LombokTest {

  private final boolean valid;
  private final boolean isGood;
}

class NonLombokTest {

  private final boolean valid;
  private final boolean isGood;

  NonLombokTest(boolean valid, boolean isGood) {
    this.valid = valid;
    this.isGood = isGood;
  }

  public boolean isValid() {
    return valid;
  }

  public boolean isGood() {
    return isGood;
  }

  /**
   * Uncommenting this would make the mapping work, as it would use the `isIsGood` function instead of `isGood`. Which is why we're having this
   * issue.
   * <p>
   * `lombokTest.valid( test.isValid() );`
   * <p>
   * `lombokTest.isGood( test.isIsGood() );`
   */
//  public boolean isIsGood() {
//    return isGood;
//  }
}

@Mapper
public interface TestMapper {

  LombokTest fromNonLombok(NonLombokTest test);

//  @Mapping(source = "good", target = "isGood")
  NonLombokTest fromLombok(LombokTest test);
}

TestMapperTest.java

package com.transferwise.swiftprocessor.mapper.event;

import org.junit.jupiter.api.Assertions;
import org.junit.jupiter.api.Test;
import org.mapstruct.factory.Mappers;

class TestMapperTest {

  TestMapper mapper = Mappers.getMapper(TestMapper.class);

  @Test
  void mapFromLombokTest() {
    LombokTest lombokTest = LombokTest.builder()
      .valid(true)
      .isGood(true)
      .build();
    NonLombokTest nonLombokTest = mapper.fromLombok(lombokTest);
    Assertions.assertTrue(nonLombokTest.isValid());
    // Fails! Unless we uncomment `@Mapping(source = "good", target = "isGood")` on `fromLombok`
    Assertions.assertTrue(nonLombokTest.isGood());
  }

  @Test
  void mapFromNonLombok() {
    NonLombokTest nonLombokTest = new NonLombokTest(true, true);
    LombokTest lombokTest = mapper.fromNonLombok(nonLombokTest);
    Assertions.assertTrue(lombokTest.isValid());
    // Fails! Unless we uncomment `isIsGood` from `NonLombokTest`
    Assertions.assertTrue(lombokTest.isGood());
  }
}