Add VoteType & CreateVote mutation

app/graphql/resolvers/create_vote.rb

@@ -0,0 +1,12 @@
+class Resolvers::CreateVote < GraphQL::Function
+  argument :linkId, !types.ID
+
+  type Types::VoteType
+
+  def call(_obj, args, ctx)
+    Vote.create!(
+      user: ctx[:current_user],
+      link: Link.find_by(id: args[:linkId]),
+    )
+  end
+end

app/graphql/types/mutation_type.rb

@@ -3,5 +3,6 @@
 
   field :createLink, function: Resolvers::CreateLink.new
   field :createUser, function: Resolvers::CreateUser.new
+  field :createVote, function: Resolvers::CreateVote.new
   field :signInUser, function: Resolvers::SignInUser.new
 end

app/graphql/types/vote_type.rb

@@ -0,0 +1,7 @@
+Types::VoteType = GraphQL::ObjectType.define do
+  name 'Vote'
+
+  field :id, !types.ID
+  field :link, -> { !Types::LinkType }
+  field :user, -> { !Types::UserType }
+end

test/graphql/resolvers/create_vote_test.rb

@@ -0,0 +1,30 @@
+require 'test_helper'
+
+class Resolvers::CreateVoteTest < ActiveSupport::TestCase
+  def perform(args = {})
+    Resolvers::CreateVote.new.call(nil, args, { current_user: @user })
+  end
+
+  setup do
+    @user = User.create!(
+      name: 'test',
+      email: 'email@example.com',
+      password: 'something'
+    )
+    @link = Link.create!(
+      url: 'http://google.com',
+      description: 'description',
+      user: @user,
+    )
+  end
+
+  test 'creating new vote' do
+    vote = perform(
+      linkId: @link.id,
+    )
+
+    assert vote.persisted?
+    assert_equal vote.link, @link
+    assert_equal vote.user, @user
+  end
+end