How to deal with general errors in Rails API? - ruby-on-rails

Question

Trying to set up rails API, getting this error, both through console and in actual API requests:
Rack app error handling request { POST /login } #<NameError: uninitialized constant ActionText::Engine::ApplicationController
This is my ApplicationController:
class ApplicationController < ActionController::API
before_action :authorized
def encode_token(payload)
JWT.encode(payload, 's3cr3t')
end
def auth_header
#requesting the header type of authorization (with token) that we will declare through our api requests
# { Authorization: 'Bearer <token>' }
request.headers['Authorization']
end
def decoded_token
if auth_header
#going to take the token and decode it
# we're only concerned about the first index which will be a token with key of *user_id*
token = auth_header.split(' ')[1]
# header: { 'Authorization': 'Bearer <token>' }
begin
JWT.decode('s3cr3t', true, algorithm: 'HS256')
rescue JWT::DecodeError
nil
end
end
end
def logged_in_user
#consults decode_token to check the header for valid information
if decoded_token
user_id = decoded_token[0]['user_id']
#user = User.find_by(id: user_id)
end
end
def logged_in?
#returns true or false
!!logged_in_user
end
def authorized
#consults logged_in? see see if user is authorized
render json: { message: 'Please log in' }, status: :unauthorized unless logged_in?
end
end
Of course I would like to sort this error specifically (syntax error?) but not sure how to tackle general errors (beyond status codes) in Rails API. Is there a good practice I should be following?
Thanks!

Answer 1

For NameError: uninitialized constant ActionText::Engine::ApplicationController, where is your ApplicationController defined? It seems like ActionText requires it to be in app/controllers/application_controller.rb and possibly inherited from ActionController::Base.
As you develop an API I don't expect you need ActionText though and just accidentally load it. You should have a look in your config/application.rb file and look what gets loaded. If there is require 'rails/all' you should only load what you really need, e.g.
require "action_controller/railtie"
require "active_record/railtie"
but not sure how to tackle general errors (beyond status codes) in Rails API
In terms of general errors, you can e.g. use a rescue_from like this
class ApplicationController < ActionController::Base
rescue_from User::NotAuthorized, with: :deny_access # self defined exception
rescue_from ActiveRecord::RecordInvalid, with: :show_errors
rescue_from 'MyAppError::Base' do |exception|
render xml: exception, status: 500
end
private
def deny_access
...
end
def show_errors(exception)
exception.record.new_record? ? ...
end
end
https://apidock.com/rails/ActiveSupport/Rescuable/ClassMethods/rescue_from
For general errors it's not really needed to have a rescue_from StandardError as this is the default behaviour of Rails. Rails has a middleware called PublicExceptions which does (mostly) what you want so you can just let the StandardError propagate.
Instead of { error: "Internal Server Error" } it will render this
{
status: status,
error: Rack::Utils::HTTP_STATUS_CODES.fetch(status, Rack::Utils::HTTP_STATUS_CODES[500])
}
which in case of an exception will render { status: 500, error: "Internal Server Error" }. This should be a reasonable compromise.
For development you could think about adapting this middleware. You can set it with config.exceptions_app.
https://guides.rubyonrails.org/configuring.html#rails-general-configuration
https://api.rubyonrails.org/classes/ActionDispatch/PublicExceptions.html
https://github.com/rails/rails/blob/master/actionpack/lib/action_dispatch/middleware/public_exceptions.rb#L14