This inspection reports when @Mapping( target = ".") is used without a source property.

//wrong
@Mapper
public interface EmployeeMapper {
    @Mapping(target = ".", expression = "java(company.getEmployee())"
    Employee toEmployee(Company company, @Context CycleAvoidingMappingContext context);
}

//correct
@Mapper
public interface EmployeeMapper {
    @Mapping(target = ".", source = "employee")
    Employee toEmployee(Company company, @Context CycleAvoidingMappingContext context);
}