DataFetcherResult support to return data & errors

DataFetcherResult was introduced in the graphql-java v7.0 to allow returning a wrapper object which will contain the data the resolver is supposed to return + a list of errors.

I took the sample project to try:

    @GraphQLMutation(name = "createVendor")
    public DataFetcherResult<Vendor> createVendor(@GraphQLArgument(name = "vendor") Vendor vendor){
        Vendor createdVendor =  new Vendor((long) mockVendorStorage.size() + 1,
                vendor.getName(),
                vendor.getAddress());
        mockVendorStorage.add(createdVendor);
        List<GraphQLError> errors = new ArrayList<>();
        errors.add(new GenericGraphQLError("invalid data"));
        return new DataFetcherResult<>(createdVendor, errors);
    }

Then I invoke the method:

mutation {
  createVendor(
    vendor: {
      id: 1
      name: "hello"
      address: {
        city: "mtl"
        postalCode:"h2c1f1"
        streetAndNumber: "123 asd"
      }
      productsInStock:[
        {
          stockSize: 1
          product:{
            id: 1
            name: "aaa"
            description:"asdas"
          }
        }
      ]
    }) {
    id
    name
  }
}

Instead of returning the data + the error, it’s just failing because spqr hasn’t extracted the data part from the DataFetcherResult:

{
  "data": null,
  "errors": [
    {
      "message": "Validation error of type FieldUndefined: Field 'id' in type 'DataFetcherResult_Vendor' is undefined",
      "locations": [
        {
          "line": 36,
          "column": 5
        }
      ],
      "description": "Field 'id' in type 'DataFetcherResult_Vendor' is undefined",
      "validationErrorType": "FieldUndefined",
      "errorType": "ValidationError",
      "path": null,
      "extensions": null
    },
    {
      "message": "Validation error of type FieldUndefined: Field 'name' in type 'DataFetcherResult_Vendor' is undefined",
      "locations": [
        {
          "line": 37,
          "column": 5
        }
      ],
      "description": "Field 'name' in type 'DataFetcherResult_Vendor' is undefined",
      "validationErrorType": "FieldUndefined",
      "errorType": "ValidationError",
      "path": null,
      "extensions": null
    }
  ],
  "extensions": null
}

Are you planning to support this new feature from graphql-java implementation, since actually it was a big missing peace from the GraphQL spec.

[kaqqao]

Glad we got it sorted out! Cheers! 🍻

[elenigen]

I was right, the source of the problem is from graphql-java and it was already fixed (#888), so it would be part of the next release.

As reference, here’s what I did to make it work:

Code

    @GraphQLMutation(name = "createVendor")
    public DataFetcherResult<Vendor> createVendor(@GraphQLArgument(name = "vendor") Vendor vendor){
        Vendor createdVendor =  new Vendor((long) mockVendorStorage.size() + 1,
                vendor.getName(),
                vendor.getAddress());
        mockVendorStorage.add(createdVendor);
        List<GraphQLError> errors = new ArrayList<>();
        errors.add(generateFakeError("invalid data1", "path1"));
        errors.add(generateFakeError("invalid data2", "path1"));
        return new DataFetcherResult<>(createdVendor, errors);
    }

    private GraphQLError generateFakeError(String message, String path) {
        return new GraphQLError() {
            @Override
            public String getMessage() {
                return "Something went wrong";
            }

            @Override
            public List<Object> getPath() {
                return Collections.singletonList(path);
            }

            @Override
            public List<SourceLocation> getLocations() {
                return null;
            }

            @Override
            public ErrorType getErrorType() {
                return ErrorType.ValidationError;
            }
        };
    }

Request

mutation {
  createVendor(
    vendor: {
      id: 1
      name: "hello"
      address: {
        city: "mtl"
        postalCode:"h2c1f1"
        streetAndNumber: "123 asd"
      }
      productsInStock:[
        {
          stockSize: 1
          product:{
            id: 1
            name: "aaa"
            description:"asdas"
          }
        }
      ]
    }) {
    id
    name
  }
}

Response

{
  "data": {
    "createVendor": {
      "id": 1,
      "name": "hello"
    }
  },
  "errors": [
    {
      "message": "invalid data1",
      "path": [
        "createVendor",
        "path1"
      ]
    },
    {
      "message": "invalid data2",
      "path": [
        "createVendor",
        "path2"
      ]
    }
  ]
}

Finally, I was able to make it work, thanks a lot for your help! 😃 🍻 🌴