implementing the sign out functionality

app/graphql/mutations/auth/sign_out.rb

@@ -0,0 +1,33 @@
+class Mutations::Auth::SignOut < GraphQL::Schema::Mutation
+  include ::Graphql::TokenHelper
+
+  argument :refresh_token,String requied: true do
+    description "refresh token for expiring the user session"
+  end
+
+  field :errors, [::Types::Auth::Error], null: false
+  field :success, Boolean, null: false
+  field :user, GraphQL::Auth.configuration.user_type.constantize, null: true
+
+  def resolve(refresh_token:)
+    if (refresh_token.nil? && refresh_token.empty?)
+      {
+        success: false,
+        errors: ["refresh token is invalid"],
+        user: nil
+      }
+    else
+      user = User.find_by_refresh_token(refresh_token)
+      delete_refresh_token(user)
+
+      {
+        success: true,
+        errors: [],
+        user: nil
+      }
+
+    end
+
+  end
+
+end

app/graphql/types/graphql_auth.rb

@@ -16,11 +16,14 @@ module Types::GraphqlAuth
 
   field :validate_token, mutation: ::Mutations::Auth::ValidateToken
 
+  field :sign_out, mutation: ::Mutations::Auth::SignOut
+
   if GraphQL::Auth.configuration.allow_lock_account
     field :lock_account, mutation: Mutations::Auth::LockAccount
   end
 
   if GraphQL::Auth.configuration.allow_unlock_account
     field :unlock_account, mutation: Mutations::Auth::UnlockAccount
   end
+
 end

spec/graphql/mutations/auth/sign_out_spec.rb

@@ -0,0 +1,72 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe Mutations::Auth::SignOut, type: :request do
+  let!(:user) do
+    user = User.create!(
+      email: 'email@example.com',
+      password: 'password'
+    )
+  end
+
+  let(:result) do
+    GraphqlSchema.execute(
+      query_string,
+      variables: variables,
+      context: context
+    )
+  end
+
+  let(:query_string) do
+    <<-GRAPHQL
+    mutation($refresh_token: String!) {
+      resetPassword(refresh_token: $refresh_token) {
+        success
+        errors {
+          field
+          message
+        }
+        user
+      }
+    }
+    GRAPHQL
+  end
+
+  let(:context) do
+    {
+      current_user: nil,
+      response: ResponseMock.new(headers: {}),
+    }
+  end
+
+  subject { result }
+
+  context "when valid paramters are given" do
+    let(:variables) do
+      {
+        "refresh_token" => user.refresh_token
+      }
+    end
+
+    it "sign out the user" do
+      subject
+
+      expect(result.dig(["data"]["success"])).to be_truthy
+    end
+  end
+  context "when invalid paramters are given" do
+    let(:variables) do
+      {
+        "refresh_token" => nil
+      }
+    end
+
+    it "returns error message" do
+      subject
+
+      expect(result.dig(["data"]["success"])).to be_falsey
+      expect(result.dig(["data"]["user"])).to nil
+    end
+  end
+end