Rails + Graphql - Failed to implement Game.id - ruby-on-rails

Question

I'm trying to implement a query type that can search by name of the record instead of id. Here's its definition in query_type.rb.
# Get game by name
field :game_by_name, Types::GameType, null: false do
argument :name, String, required: true
end
def game_by_name(name:)
Game.where(name: name) //find a game using the name attribute
end
But when I run:
query {
gameByName(name: "League of Legends") {
id
name
}
}
I get the following error.
Failed to implement Game.id, tried:\n\n
- `Types::GameType#id`, which did not exist\n
- `Game::ActiveRecord_Relation#id`, which did not exist\n
- Looking up hash key `:id` or `\"id\"` on `#<Game::ActiveRecord_Relation:0x00007f5644442888>`, but it wasn't a Hash\n\n
To implement this field, define one of the methods above (and check for typos)\n
This is odd because the following query type works perfectly.
# Get game by ID
field :game_by_id, Types::GameType, null: false do
argument :id, ID, required: true
end
def game_by_id(id:)
Game.find(id)
end
Here's game_type.rb:
module Types
class GameType < Types::BaseObject
field :id, ID, null: false
field :name, String, null: false
end
end
How do I go about fixing this? Thank you!

Answer 1

I stumbled upon this, chasing a similar error. Not sure if you solved it or not, but I believe the issue is in the query type definition.
You're telling it to return a type of Types::GameType, but the Active Record query returns an Active Record Relation, which is a collection. So, graphql is expecting a single instance of Game, but is instead receiving a collection. Graphql is then trying to map the returned value from the query to the type definition, but is unable to. The best hint is from this line:
Looking up hash key `:id` or `\"id\"` on `#<Game::ActiveRecord_Relation:0x00007f5644442888>`, but it wasn't a Hash..
Graphql is trying to assign :id to the ActiveRecord_Relation and it can't do it.
Two paths forward, depending on how you want the API to behave. Do you want it to return 1 record or many?
Wrapping the Types::GameType within brackets will tell graphql it's a collection and to iterate over the records
# Get game by name
field :game_by_name, [Types::GameType], null: false do
argument :name, String, required: true
end
def game_by_name(name:)
Game.where(name: name) //find a game using the name attribute
end
or have Active Record return just 1 record, something like...
# Get game by name
field :game_by_name, Types::GameType, null: false do
argument :name, String, required: true
end
def game_by_name(name:)
Game.where(name: name).limit(1).first //find a game using the name attribute
end
I know this is months old, but just putting it out there for anyone else who stumbles upon this question, like I did!