Graphql-ruby: While using variables and posting to graphql, it is wrongly converting Float inputs into Strings.

[arjunrajkumar]

Hello,

While using variables for posting to /graphql from RSpec, it is automatically converting the variable inputs to strings.

For e.g. I have this mutation

module Mutations
  class UpdateCreditEntryMutation < Mutations::BaseMutation
    class UpdateCreditEntryInput < Types::BaseInputObject
      argument :contact_id, ID, required: false
      argument :amount, Float, required: true
    end

    argument :id, ID, required: true
    argument :input, UpdateCreditEntryInput, required: false

    type Types::CreditEntryType

    null false

    def resolve(id:, input:)
      ...
    end
  end
end

And, in my Rspec tests, I am defining the query this way.

let(:gql) do
        <<~GRAPHQL
          mutation UpdateCreditEntryMutation($id: ID!, $input: UpdateCreditEntryInput!) {
            updateCreditEntry(id: $id, input: $input) {
              id
            }
          }
        GRAPHQL
      end

And then posting to GraphQL via this:

variables = { id: ce.id, input: { amount: 200.00, updatedAt: '2020-01-01' } }

          post '/graphql', headers: { 'X-Token' => session.token }, params: {
            query: gql,
            variables: variables
          }

But I get an error because the amount is supposed to be a float, but it gets automatically converted into a string.

This is the error:

{"errors"=>[{"message"=>"Variable input of type UpdateCreditEntryInput! was provided invalid value for amount (Could not coerce value \"200.0\" to Float)", "locations"=>[{"line"=>1, "column"=>46}], "extensions"=>{"value"=>{"amount"=>"200.0", "updatedAt"=>"2020-01-01"}, "problems"=>[{"path"=>["amount"], "explanation"=>"Could not coerce value \"200.0\" to Float"}]}}]}

If I change the amount to type string in my mutation input - everything will pass.
Here is is converting the amount into a string:

"extensions"=>{"value"=>{"amount"=>"200.0", "updatedAt"=>"2020-01-01"}

Wondering why it is converting the float into a string. Or maybe I am calling the inputs the wrong way? If so, will delete this issue.

Thanks.

[rmosolgo]

Hi, it looks like you're passing graphql variables as query parameters (eg ?variables[amount]=200.00) is that right?

If so, then you have to recognize that they won't be parsed by Rails into anything but strings. Query parameters don't have any typing information, so Rails can't tell that you mean 200.0, not "200.00".

You could confirm this by debugging in your controller:

p ["Variables param:", params[:variables]]
# What do you see in the log for this?

To work around this, use a JSON request body instead of query parameters. For example:

post "/graphql", format: :json, params: { ... }

(I think format: :json will do the trick -- you might have to use .to_json on the params, too)

Let me know if that helps!

[arjunrajkumar]

Thank you! It worked after adding what you suggested.

post "/graphql", headers: { 'Content-Type' => 'application/json', 'X-Token' => session.token }, params: params.to_json