Add wrong mutation type

Gemfile

@@ -34,6 +34,7 @@ gem 'jbuilder', '~> 2.5'
 
 # Use Capistrano for deployment
 # gem 'capistrano-rails', group: :development
+gem 'graphql'
 
 group :development, :test do
   # Call 'byebug' anywhere in the code to stop execution and get a debugger console
@@ -47,7 +48,10 @@ group :development do
   # Spring speeds up development by keeping your application running in the background. Read more: https://github.com/rails/spring
   gem 'spring'
   gem 'spring-watcher-listen', '~> 2.0.0'
+  gem 'graphiql-rails'
 end
 
 # Windows does not include zoneinfo files, so bundle the tzinfo-data gem
 gem 'tzinfo-data', platforms: [:mingw, :mswin, :x64_mingw, :jruby]
+
+gem 'graphiql-rails', group: :development

Gemfile.lock

@@ -55,6 +55,9 @@ GEM
     ffi (1.9.18)
     globalid (0.3.7)
       activesupport (>= 4.1.0)
+    graphiql-rails (1.4.1)
+      rails
+    graphql (1.5.5)
     i18n (0.8.1)
     jbuilder (2.6.3)
       activesupport (>= 3.0.0, < 5.2)
@@ -156,6 +159,8 @@ PLATFORMS
 DEPENDENCIES
   byebug
   coffee-rails (~> 4.2)
+  graphiql-rails
+  graphql
   jbuilder (~> 2.5)
   jquery-rails
   listen (~> 3.0.5)

app/controllers/graphql_controller.rb

@@ -0,0 +1,32 @@
+class GraphqlController < ApplicationController
+  def execute
+    variables = ensure_hash(params[:variables])
+    query = params[:query]
+    context = {
+      # Query context goes here, for example:
+      # current_user: current_user,
+    }
+    result = ReproduceGraphqlHangSchema.execute(query, variables: variables, context: context)
+    render json: result
+  end
+
+  private
+
+  # Handle form data, JSON body, or a blank value
+  def ensure_hash(ambiguous_param)
+    case ambiguous_param
+    when String
+      if ambiguous_param.present?
+        ensure_hash(JSON.parse(ambiguous_param))
+      else
+        {}
+      end
+    when Hash, ActionController::Parameters
+      ambiguous_param
+    when nil
+      {}
+    else
+      raise ArgumentError, "Unexpected parameter: #{ambiguous_param}"
+    end
+  end
+end

app/graphql/mutations/create_post.rb

@@ -0,0 +1,12 @@
+Mutations::CreatePost = GraphQL::Relay::Mutation.define do
+  name "CreatePost"
+  # TODO: define return fields
+  # return_field :post, Types::PostType
+
+  # TODO: define arguments
+  # input_field :name, !types.String
+
+  resolve ->(obj, args, ctx) {
+    # TODO: define resolve function
+  }
+end

app/graphql/reproduce_graphql_hang_schema.rb

@@ -0,0 +1,4 @@
+ReproduceGraphqlHangSchema = GraphQL::Schema.define do
+  query(Types::QueryType)
+  mutation(Types::MutationType)
+end

app/graphql/types/mutation_type.rb

@@ -0,0 +1,5 @@
+Types::MutationType = GraphQL::ObjectType.define do
+  name 'Mutation'
+
+  field :createPost, field: Mutations::CreatePost
+end

app/graphql/types/query_type.rb

@@ -0,0 +1,13 @@
+Types::QueryType = GraphQL::ObjectType.define do
+  name "Query"
+  # Add root-level fields here.
+  # They will be entry points for queries on your schema.
+
+  # TODO: remove me
+  field :testField, types.String do
+    description "An example field added by the generator"
+    resolve ->(obj, args, ctx) {
+      "Hello World!"
+    }
+  end
+end

config/routes.rb

@@ -1,3 +1,8 @@
 Rails.application.routes.draw do
+  if Rails.env.development?
+    mount GraphiQL::Rails::Engine, at: "/graphiql", graphql_path: "/graphql"
+  end
+
+  post "/graphql", to: "graphql#execute"
   # For details on the DSL available within this file, see http://guides.rubyonrails.org/routing.html
 end