SPQR Dataloder doesn't allow null values - Exception while fetching data : null

[BenNeighbour]

@kaqqao @ellebrecht @jestan @heruan @vojtechhabarta Hi all,

I have set up some batch DataLoaders for each entity (that have relationships with others) in order to solve the N+1 Problem with GraphQL/SPQR - and it works. HOWEVER, when I have a @OneToOne or @ManyToMany relation on some entity that is null, an Exception while fetching data (/getAllEmployees[6]/company) : null.

Here is the resolver for the company field of each employee:

@GraphQLQuery(name = "company")
public CompletableFuture<Company> getCompany(
        @GraphQLContext @Valid @GraphQLNonNull Employee employee, @GraphQLEnvironment ResolutionEnvironment env) {
  DataLoader<UUID, Company> loader = env.dataFetchingEnvironment.getDataLoader("company");
  return loader.load(employee.getCompany().getId());
}

And the DataFetcher,

@Component
public class DataLoaderFactory implements DataLoaderRegistryFactory {

  private static CompanyDao companyDao;
  private static final BatchLoader<UUID, Company> companyLoader = DataLoaderFactory::companies;
  /* ...... */

  @Autowired
  public DataLoaderFactory(CompanyDao companyDao, /* ...... */) {
    DataLoaderFactory.companyDao = companyDao;
    /* ...... */
  }

  public static CompletableFuture<List<Company>> companies(List<UUID> ids) {
    return CompletableFuture.completedFuture(companyDao.findAllById(ids));
  }

  /* ...... */

  @Override
  @Bean
  public DataLoaderRegistry createDataLoaderRegistry() {
    DataLoaderRegistry allLoaders = new DataLoaderRegistry();
    allLoaders.register("company", new DataLoader<>(companyLoader));
    /* ...... */

    return allLoaders;
  }
}

And for some context, here are the entities:

For the Employee

@Setter
@Getter
@Entity
@NoArgsConstructor
@AllArgsConstructor
public class Employee implements Serializable {

  private static final long serialVersionUID = 684733882540759135L;

  @Id
  @GeneratedValue
  @Column(columnDefinition = "uuid", updatable = false)
  @GraphQLQuery(name = "id", description = "A Person's Id")
  private UUID id;

  @NotNull(message = "There must be a Person's Name!")
  @GraphQLQuery(name = "fullName", description = "A Person's Name")
  private String fullName;

  @NotNull(message = "A Person must have an Age!")
  @GraphQLQuery(name = "age", description = "A Person's Age")
  private int age;

  @NotNull(message = "A Person must have a Vehicle!")
  @GraphQLQuery(name = "personalVehicle", description = "A Person's Mode of Transport")
  private Vehicle personalVehicle;

  @ManyToOne(targetEntity = Company.class, fetch = FetchType.LAZY, cascade = CascadeType.ALL)
  @GraphQLQuery(name = "company", description = "The Company a Person works for")
  private Company company;

  @GraphQLQuery(name = "roles", description = "The Role a Person plays in their Company")
  @OneToMany(
      targetEntity = Role.class,
      orphanRemoval = true,
      fetch = FetchType.LAZY,
      mappedBy = "employee",
      cascade = CascadeType.ALL)
  private List<Role> roles = new ArrayList<>();

  public enum Vehicle {
    CAR,
    BUS,
    VAN,
    BICYCLE,
    MOTORBIKE,
    SCOOTER
  }
}

For the Company

@Setter
@Getter
@Entity
@NoArgsConstructor
@AllArgsConstructor
public class Company implements Serializable {

  private static final long serialVersionUID = -6007975840330441233L;

  @Id
  @GeneratedValue
  @Column(columnDefinition = "uuid", updatable = false)
  @GraphQLQuery(name = "id", description = "A Company's Id")
  private UUID id;

  @NotNull(message = "There must be a Company Name!")
  @GraphQLQuery(name = "name", description = "A Company's Name")
  private String name;

  @Min(10000)
  @NotNull(message = "You gotta tell us how rich you are!")
  @GraphQLQuery(name = "balance", description = "A Company's Dollar")
  private BigDecimal balance;

  @NotNull(message = "There must be a Company Type!")
  @GraphQLQuery(name = "type", description = "The type of company")
  private CompanyType type;

  @GraphQLQuery(name = "offices", description = "The Company's offices")
  @OneToMany(
      targetEntity = Office.class,
      orphanRemoval = true,
      fetch = FetchType.LAZY,
      mappedBy = "company",
      cascade = CascadeType.ALL)
  private List<Office> offices;

  public enum CompanyType {
    PRIVATE_LIMITED,
    SOLE_TRADER,
    PUBLIC
  }
}

Any help, comments or clarification would be much, much appreciated - I'm probably missing out something stupid!!

[BenNeighbour]

Also my build.gradle dependency for this is: implementation "io.leangen.graphql:graphql-spqr-spring-boot-starter:0.0.6"

[BenNeighbour]

This is a duplicate of this issue - trying to get more traction as I've tried everything to make it work...

[kaqqao]

Closing this as all the activity is happening on the linked original.