ruby-graphql + HTTP GET

graphql_controller.rb

class GraphqlController < ApplicationController
  include EnsureHash

  def execute
    result = GraphqlSchema.execute(
      params[:query],
      variables: ensure_hash(params[:variables]),
      context: context,
      operation_name: params[:operationName],
    )

    render json: result
  end

  private

  def context
    @context ||= {
      request: request,
    }
  end
end

graphql_schema.rb

class GraphqlSchema < GraphQL::Schema
  query_analyzer Analyzers::HttpMethodAnalyzer.new
end

http_method_analyzer.rb

class HttpMethodAnalyzer
  def analyze?(query)
    !!query.context[:request]
  end

  def initial_value(query)
    {
      get_request: query.context[:request].get?,
      mutation: query.mutation?,
    }
  end

  def call(memo, _visit_type, _irep_node)
    memo
  end

  def final_value(memo)
    return if !memo[:get_request] || !memo[:mutation]

    GraphQL::AnalysisError.new("Mutations cannot be performed via HTTP GET")
  end
end

routes.rb

require "sidekiq/web"
require "sidekiq/grouping/web"
require "sidekiq-scheduler/web"

Rails.application.routes.draw do
  get "/graphql", to: "graphql#execute"
  post "/graphql", to: "graphql#execute"
end