false errors on "unknown properties" after Pull Request #177 got merged

[OlliL]

We are experiencing multiple "Cannot resolve symbol ...." errors with version 1.9.0 of the plugin.

We are currently not able reproduce all of them them with simple projects, but it seems to be connected to not detecting properties defined in abstract classes together with Generics. We'll further investigate into this, but maybe you can check on your side too - you know your code and the edge cases probably far better then we do.

One thing we can reproduce is the handling of final List-properties in target objects having no setter.
Mapstruct will in this case use the getter and call addAll on it to add the mapped elements.
I saw in TargetUtils.javathat you also have code in place to look for getters working with classes implementing java.util.Collection - but something seems not to work right in that place.

Let me provide a simple example:

Class TestDto

package test;
import java.util.List;

public class TestDto {
    private List<String> dtoStringList;
    public List<String> getDtoStringList() {
        return dtoStringList;
    }
}

Class TestEntity

package test;
import java.util.List;
import java.util.ArrayList;

public class TestEntity {
    private final List<String> myStringList = new ArrayList<>();
    public List<String> getMyStringList() {
        return myStringList;
    }
}

Class TestEntityMapper

package test;
import org.mapstruct.Mapper;
import org.mapstruct.Mapping;

@Mapper
public interface TestEntityMapper {
    @Mapping(target = "myStringList", source = "dtoStringList")
    TestEntity map(TestDto testDto);
}

This will generate an error:
Cannot resolve symbol 'myStringList'

But the generated mapper is fine, it uses the get-Method and calls addAll() on it. So this is a false error.

[filiphr]

Thanks for reporting this @OlliL. Can you perhaps check how it was in the previous version? Was the method being resolved, i.e. if you used "Find Usages" or if you would click to navigate in the Mapping#target would it navigate to the method? Was it being auto completed?

I am asking this questions as PR #177 didn't do any particular functional change, so I want to rule out something. We'll try out your example as well and we should fix it asap.

[OlliL]

I switched back to 1.8.0. The text in target is not clickable while text in other target properties (which are not reported as errors in 1.9.0) are clickable. So it seems to be a Problem which already existed in 1.8.0 but didn't surfaced because it wasn't treated as error.

What I notice - in 1.8.0 the property is available with code completion - I can select it - but inside the code completion modal, no property type is shown. Usually Properties have 2 columns in this list - name + type. Types like "Integer" or List are shown as types - but in this case no type at all is shown - the part of the selection-list-popup is just empty as if this property had no type.

[OlliL]

I was finally able to reproduce our other errors we noticed.
It has to do with Abstraction in combination with Lomboks SuperBuilder

Take this Code:

Class AbstractEntityId:

package test.test2;
import lombok.experimental.SuperBuilder;

@SuperBuilder
public abstract class AbstractEntityId {

    private final String value;
    protected AbstractEntityId(final String value) {
        this.value = value;
    }
    public final String getValue() {
        return value;
    }
}

Class EntityId:

package test.test2;
import lombok.experimental.SuperBuilder;

@SuperBuilder
public class EntityId extends AbstractEntityId {
    public EntityId(final String value) {
        super(value);
    }
}

Class TestMapper

package test.test2;
import org.mapstruct.Mapper;
import org.mapstruct.Mapping;

@Mapper
public interface TestMapper {
    @Mapping(target = "value", source = "id")
    EntityId mapEntityId(String id);
}

"value" gets reported as "Cannot resolve symbol". The generated mapper is fine. If you remove the SuperBuilder annotation, the error will vanish.

[OlliL]

And one more.... if you have an Object with a cusom getter, returning a complex object (not String for example), you have to specify it as ignore, otherwise Mapstruct will give an error, that the target prop is missing.
When you specify it as ignore, the Plugin will now report an error:

Class ComplexObject

package test.test3;

public class ComplexObject {
    private String something;
}

Class AbstractEntity

package test.test3;

public abstract class AbstractEntity {
    public ComplexObject getSomething() {
        return null;
    }
}

Class TestGetMapper

package test.test3;

import org.mapstruct.Mapper;
import org.mapstruct.Mapping;

@Mapper
public interface TestGetMapper {
    @Mapping(target = "something", ignore = true)
    AbstractEntity mapEntity(final String dto);
}

--> Cannot resolve symbol 'something'
If you dont mark it as ignore at all:
Mapstruct reports: Unmapped target property: something

[OlliL]

Enum Mapping is broken as well

Class TestEnum

package test.test4;

public enum TestEnum {
    PENCIL,
    PEN
}

Class EnumMapper

package test.test4;

import org.mapstruct.Mapper;
import org.mapstruct.ValueMapping;

@Mapper
public interface EnumMapper {

    @ValueMapping(target = "1", source = "PEN")
    @ValueMapping(target = "whatever", source = "PENCIL")
    String mapTestEnum(TestEnum testEnum);

}

Both targets are marked as error

[filiphr]

Thanks for the details @OlliL. All of those use cases are different things, which didn't work before and now they are being treated as errors instead of just not being clickable like before.

We'll look into it