Fix rubocop violations. Fix Travis build.

lib/googleauth/user_authorizer.rb

@@ -32,7 +32,6 @@ require 'multi_json'
 require 'googleauth/signet'
 require 'googleauth/user_refresh'
 
-# rubocop:disable ClassLength
 module Google
   module Auth
     # Handles an interactive 3-Legged-OAuth2 (3LO) user consent authorization.
@@ -125,11 +124,7 @@ module Google
       # @return [Google::Auth::UserRefreshCredentials]
       #  Stored credentials, nil if none present
       def get_credentials(user_id, scope = nil)
-        raise NIL_USER_ID_ERROR if user_id.nil?
-        raise NIL_TOKEN_STORE_ERROR if @token_store.nil?
-
-        scope ||= @scope
-        saved_token = @token_store.load(user_id)
+        saved_token = stored_token(user_id)
         return nil if saved_token.nil?
         data = MultiJson.load(saved_token)
 
@@ -146,6 +141,7 @@ module Google
           refresh_token: data['refresh_token'],
           expires_at: data.fetch('expiration_time_millis', 0) / 1000
         )
+        scope ||= @scope
         if credentials.includes_scope?(scope)
           return monitor_credentials(user_id, credentials)
         end
@@ -245,6 +241,18 @@ module Google
 
       private
 
+      # @private Fetch stored token with given user_id
+      #
+      # @param [String] user_id
+      #  Unique ID of the user for loading/storing credentials.
+      # @return [String] The saved token from @token_store
+      def stored_token(user_id)
+        raise NIL_USER_ID_ERROR if user_id.nil?
+        raise NIL_TOKEN_STORE_ERROR if @token_store.nil?
+
+        @token_store.load(user_id)
+      end
+
       # Begin watching a credential for refreshes so the access token can be
       # saved.
       #
@@ -268,14 +276,10 @@ module Google
       def redirect_uri_for(base_url)
         return @callback_uri unless URI(@callback_uri).scheme.nil?
         if base_url.nil? || URI(base_url).scheme.nil?
-          raise sprintf(
-            MISSING_ABSOLUTE_URL_ERROR,
-            @callback_uri
-          )
+          raise sprintf(ISSING_ABSOLUTE_URL_ERROR, @callback_uri)
         end
         URI.join(base_url, @callback_uri).to_s
       end
     end
   end
 end
-# rubocop:enable ClassLength

lib/googleauth/user_refresh.rb

@@ -75,7 +75,7 @@ module Google
       # JSON key.
       def self.read_json_key(json_key_io)
         json_key = MultiJson.load(json_key_io.read)
-        wanted = %w(client_id client_secret refresh_token)
+        wanted = %w[client_id client_secret refresh_token]
         wanted.each do |key|
           raise "the json is missing the #{key} field" unless json_key.key?(key)
         end

lib/googleauth/web_user_authorizer.rb

@@ -227,7 +227,7 @@ module Google
       # @param [Rack::Request] request
       #  Current request
       def self.validate_callback_state(state, request)
-        if state[AUTH_CODE_KEY].nil?
+        if state[AUTH_CODE_KEY].nil? # rubocop:disable Style/GuardClause
           raise Signet::AuthorizationError, MISSING_AUTH_CODE_ERROR
         elsif state[ERROR_CODE_KEY]
           raise Signet::AuthorizationError,