问Google::Apis::AuthorizationError (未经授权)

EN

Signet::AuthorizationError (Authorization failed.  Server message:
{
  "error" : "invalid_grant",
  "error_description" : "Token has been expired or revoked."
})

class User   
  def authentication(linked_account)
    client = Signet::OAuth2::Client.new(
    authorization_uri: 'https://accounts.google.com/o/oauth2/auth',
    token_credential_uri: Rails.application.secrets.token_credential_uri,
    client_id: Rails.application.secrets.google_client_id,
    client_secret: Rails.application.secrets.google_client_secret,
    scope: 'https://www.googleapis.com/auth/gmail.readonly, https://www.googleapis.com/auth/userinfo.email, https://www.googleapis.com/auth/userinfo.profile',
    redirect_uri: Rails.application.secrets.redirect_uri,
    refresh_token: linked_account[:refresh_token]
  )

  client.update!(access_token: linked_account.token, expires_at: linked_account.expires_at)
  return  AccessToken.new(linked_account.token) unless client.expired?
  auth.fetch_access_token! 
 end

 def get_email(linked_account)
   auth = authentication(linked_account)
   gmail = Google::Apis::GmailV1::GmailService.new
   gmail.client_options.application_name = User::APPLICATION_NAME
   gmail.authorization = AccessToken.new(linked_account.token)
   query = "(is:inbox OR is:sent)"
   gmail.list_user_messages(linked_account[:uid], q: "#{query}")
   ## Getting error over here ^^
  end
end // class end 

class AccessToken
  attr_reader :token
  def initialize(token)
    @token = token
  end

  def apply!(headers)
    headers['Authorization'] = "Bearer #{@token}"
  end
end