Fix bug with GQL 1.10

Author: mcelicalderon

Appraisals

@@ -47,6 +47,12 @@ appraise 'rails5.2-graphql1.9' do
   gem 'graphql', '~> 1.9.0'
 end
 
+appraise 'rails5.2-graphql1.10' do
+  gem 'sqlite3', '~> 1.3.6'
+  gem 'rails', github: 'rails/rails', branch: '5-2-stable'
+  gem 'graphql', '~> 1.10.0'
+end
+
 appraise 'rails6.0-graphql1.8' do
   gem 'sqlite3', '~> 1.4'
   gem 'devise', '>= 4.7'
@@ -61,6 +67,13 @@ appraise 'rails6.0-graphql1.9' do
   gem 'graphql', '~> 1.9.0'
 end
 
+appraise 'rails6.0-graphql1.10' do
+  gem 'sqlite3', '~> 1.4'
+  gem 'devise', '>= 4.7'
+  gem 'rails', github: 'rails/rails', branch: '6-0-stable'
+  gem 'graphql', '~> 1.10.0'
+end
+
 appraise 'rails_edge-graphql_edge' do
   gem 'sqlite3', '~> 1.4'
   gem 'devise_token_auth', github: 'lynndylanhurley/devise_token_auth', branch: 'master'

gemfiles/rails5.2_graphql1.10.gemfile

@@ -0,0 +1,9 @@
+# This file was generated by Appraisal
+
+source "https://rubygems.org"
+
+gem "sqlite3", "~> 1.3.6"
+gem "rails", github: "rails/rails", branch: "5-2-stable"
+gem "graphql", "~> 1.10.0"
+
+gemspec path: "../"

gemfiles/rails6.0_graphql1.10.gemfile

@@ -0,0 +1,10 @@
+# This file was generated by Appraisal
+
+source "https://rubygems.org"
+
+gem "sqlite3", "~> 1.4"
+gem "devise", ">= 4.7"
+gem "rails", github: "rails/rails", branch: "6-0-stable"
+gem "graphql", "~> 1.10.0"
+
+gemspec path: "../"

lib/graphql_devise/rails/routes.rb

@@ -63,7 +63,9 @@ def mount_graphql_devise_for(resource, opts = {})
         GraphqlDevise::Types::MutationType.field("#{mapping_name}_#{action}", mutation: used_mutation)
       end
 
-      GraphqlDevise::Schema.mutation(GraphqlDevise::Types::MutationType) if used_mutations.present?
+      if GraphqlDevise::Schema.mutation.nil? && used_mutations.present?
+        GraphqlDevise::Schema.mutation(GraphqlDevise::Types::MutationType)
+      end
 
       used_queries = if only_operations.present?
         default_queries.slice(*only_operations)