Mutation cannot return Array of GraphQL::ExecutionErrors

[ndac-todoroki]

Thanks to #1230 & #1231, Arrays of GraphQL::ExecutionErrors are valid returns.
Although this could be done in GraphQL::Schema::Objects, it doesn't work on GraphQL::Schema::RelayClassicMutations.

examples

https://github.com/ndac-todoroki/graphql-ruby-test
do rails server and post queries to /graphql

• Query example

query testField {
  testField
}

• Mutation example

mutation testMutation {
  addFoo(input: {}) {
    foo
  }
}

what is expected

Both returns errors like

{
  "data": null,
  "errors": [
    {
      "message": "one",
      "locations": [
        {
          "line": 2,
          "column": 3
        }
      ],
      "path": [
        "testField",
        0
      ]
    },
    ...
  ]
}

what happens

The query example returns the error above as expected.
The mutation example, in contrast returns an error like this:

{
  "error": "Unexpected token T in JSON at position 0"
}

Rails console log:

Started POST "/graphql" for 127.0.0.1 at 2018-06-15 12:06:47 +0900
Processing by GraphqlController#execute as */*
  Parameters: {"operationName"=>"testMutation", "variables"=>{}, "query"=>"mutation testMutation {\n  addFoo(input:{}) {\n    foo\n  }\n}\n", "graphql"=>{"operationName"=>"testMutation", "variables"=>{"input"=>{"lessonId"=>4000}}, "query"=>"mutation testMutation {\n  addFoo(input: {}) {\n    foo\n  }\n}\n"}}
Completed 500 Internal Server Error in 2ms (ActiveRecord: 0.0ms)



TypeError (no implicit conversion of Symbol into Integer):

app/controllers/graphql_controller.rb:10:in `execute'

environment

graphiql-rails (1.4.10)
  railties
  sprockets-rails
graphql (1.8.3)

[rmosolgo]

Thanks for the bug report! Sounds like an inconsistency in Schema::RelayClassicMutation 😖

[rmosolgo]

I don't have plans to work more on this. If you need to add multiple execution errors, you can use extras [:execution_errors] in your mutation, then

def resolve(execution_errors:, ...) 
  execution_errors.add(GraphQL::ExecutionError.new(...))
  execution_errors.add(GraphQL::ExecutionError.new(...))
end 

Let me know if that doesn't work! You can find the API docs for that object here: https://graphql-ruby.org/api-doc/1.9.11/GraphQL/Query/Context/ExecutionErrors