Here the docu: https://relishapp.com/rspec/rspec-mocks/v/3-0/docs/message-expectations/expect-a-message-on-any-instance-of-a-class
Im wondering what is the right use of it.
I have a controller
class UserController < ApplicationController
def edit
generate_token!
end
end
And the method generate_token! is defined in the model.
class User < ActiveRecord::Base
def generate_token!
self.update!(token: 'something')
end
end
I just want to check if the method receives something.
The spec would be something like.
describe 'edit'
it 'receives something' do
expect_any_instance_of(Object).to receive(:generate_token!)
end
end
But what do I have to use for the Object? I tried the class and some other random stuff, but nothing worked yet. It seems I dont get the Mock at all.
Any suggestions?
best regards
denym_
You need to replace Object with Client in your spec. Also the method's name is only "generate_token" not "generate_token!" as you have in your spec currently.
It seems you are mixing the generate_token! in your controller and the generate_token method in your Client model.
In the edit action you are calling the generate_token! defined in the same class (controller) (I would assume you only pasted the edit action here, so you might really have this method in your controller).
Anyway, if you do not have a generate_token! method in your controller which has a line like that:
#client.generate_token
the generate_token inside your Client model will never get called from your controller.
One more thing: the name of the controller that handles your client records really called users_controller?
That could also cause problem, if you really have a separate User and Client model.
I think now I know what could be your main confusion.
Expect only set your expectation. You still need to create the instance of the class and trigger the action where you are expecting something that you want to see to happen.
Eg. if you are testing a controller action you need to call the edit action after you set your expectation.
client = create(:client)
get :edit, id: client
Related
In user's home page I want to show the user's phrases.
class StaticPagesController < ApplicationController
def home
if user_signed_in?
#phrases = current_user.phrases.decorate
end
end
end
But this fails by Could not infer a decorator. I understand the error happens because only in proper controller I can use the decorate method.
I've read this post, but I may misunderstand it.
So if I want to use decorate method in situation like this, what is a good way to solve it?
I have the following classes:
class AwardBase
class AwardOne < AwardBase
class Post < ActiveRecord::Base
The Post is an ActiveRecord, and the Award has a can_award? class method which takes a post object and checks to see if it meets some criteria. If yes, it updates post.owner.awards.
I know I can do this using an Observer pattern (I tested it and the code works fine). However, that requires me to add additional code to the model. I'd like not to touch the model at all if possible. What I'd like to do is run the Award checks like this (the trigger will be invoked at class load time):
class AwardOne < AwardBase
trigger :post, :after_save
def self.can_award?(post)
...
end
end
The intention with the above code is that it should automatically add AwardOne.can_award? to Post's after_save method
So essentially what I'm trying to do is to get the trigger call be equivalent to:
class Post < ActiveRecord::Base
after_save AwardOne.can_award?(self)
...
end
which is basically:
class Post < ActiveRecord::Base
after_save :check_award
def check_award
AwardOne.can_award?(self)
end
end
How can I do this without modifying the Post class?
Here's what I've done (which does not appear to work):
class AwardBase
def self.trigger (klass, active_record_event)
model_class = klass.to_class
this = self
model_class.instance_eval do
def award_callback
this.can_award?(self)
end
end
model_class.class_eval do
self.send(active_record_event, :award_callback)
end
end
def self.can_award? (model)
raise NotImplementedError
end
end
The above code fails with the error:
NameError (undefined local variable or method `award_callback' for #<Post:0x002b57c04d52e0>):
You should think about why you want to do it this way. I would argue it is even worse than using the observer pattern. You are violating the principle of least surprise (also called principle of least astonishment).
Imagine that this is a larger project and I come as a new developer to this project. I am debugging an issue where a Post does not save correctly.
Naturally, I will first go through the code of the model. I might even go through the code of the posts controller. Doing that there will be no indication that there is a second class involved in saving the Post. It would be much harder for me to figure out what the issue is since I would have no idea that the code from AwardOne is even involved.
In this case it would actually be most preferable to do this in the controller. It is the place that is easiest to debug and understand (since models have enough responsibilities already and are generally larger).
This is a common issue with metaprogramming. Most of the time it is better to avoid it precisely because of principle of least surprise. You will be glad you didn't use it a year from now when you get back to this code because of some issue you need to debug. You will forget what "clever" thing you have done. If you don't have a hell-of-a-good reason then just stick to the established conventions, they are there for a reason.
If nothing else then at least figure out a way to do this elegantly by declaring something in the Post model. For example by registering an awardable class method on ActiveRecord::Base. But the best approach would probably be doing it in the controller or via a service object. It is not the responsibility of AwardOne to handle how Post should be saved!
Because you are adding award_callback as class method. I bet it will be registered if you grep class methods.
So change your code like below. It should work fine.
model_class.class_eval do ## Changed to class_eval
def award_callback
this.can_award?(self)
end
end
Let me give a detailed example if it sounds confusing.
class Test
end
Test.instance_eval do
def class_fun
p "from class method "
end
end
Test.class_eval do
def instance_fun
p "from instance method "
end
end
Test.methods.grep /class_fun/
# => [:class_fun]
Test.instance_methods.grep /instance_fun/
# => [:instance_fun]
Test.class_fun
# => "from class method "
Test.new.instance_fun
# => "from instance method "
I have an app that has users whose profiles are accessible via site.com/username. When choosing a username, I make an AJAX call to a method in my UsersController to make sure the username is available (and check on the back end as well when submitted). I now want to add groups that will also be accessible through site.com/groupname. Since group and user names cannot collide, whatever controller method that responds to the AJAX call will need to check both so the check_username_available and check_groupname_available methods will do the exact same thing. What's the best practice / Rails way to handle this since I don't want to replicate code in both UsersController and GroupsController?
Having a method for each controller seems a bit redundant, even if the functionality is pulled out to a helper, since there will still be two routes that do the same thing. Having a separate controller solves the problem too but not sure this is good Rails practice.
code that is reused can be shared via a module
class UsersController < ActionController::Base
include NameUniqueness
end
class GroupsController < ActionController::Base
include NameUniqueness
end
module NameUniqueness
protected
def check_name
# implementation here
end
end
both controllers will now have access the check_name instance method.
DanPickett's answer is great.
Another choice is to make a class method in the user model and just call it from each controller. Since this name checking seems like a job for the model, that's what I would do.
class User
def self.check(stuff) ...
I have a
class CommentsController < ApplicationController
def foo
session[:comments] ||= {}
comment = Comment.new(params[:comment])
# Validation and such
session[:comments][comment.post_id] = comment
#several redirections and remote authentications. User returns to another method,
# But for the sake of the example, we continue here.
CommentsController.publish_from_session
end
def self.publish_from_session
session[:comments].each do |comment|
comment.save!
end
end
end
This gives me a can't convert Symbol into Integer error. When diving into this, apparently session is simply not available, or not a hash. It might be that calling CommentsController.some_method is plain wrong.
What would be the correct solution?
Also: As mentioned in the commented code, the real deal is a bit more complex. The user returns either on another controller (sessions controller via oauth) or on yet another method on the CommentsController. See controllers calling eachother and Comments created after Oauth for how I came to this.
session is an instance method. You can't access it in a class method, but you can pass it (or just session[:comments] to the class method.
I am trying to access an instance variable which is set in the controller in the model. The controller is the products controller and the model is the products model. The instance variable is a instance of another model called account.
The instance variable is #current_account
When I run the code nothing happens, I do not get an error. Does anyone know where I can find something read about access instance variables set in the controller from the model?
Thanks
Eef
You shouldn't generally try to access the controller from the model for high-minded issues I won't go into.
I solved a similar problem like so:
class Account < ActiveRecord::Base
cattr_accessor :current
end
class ApplicationController < ActionController::Base
before_filter :set_current_account
def set_current_account
# set #current_account from session data here
Account.current = #current_account
end
end
Then just access the current account with Account.current
DISCLAIMER: The following code breaks MVC conventions, that said...
Using class attributes can probably lead to thread safety issues. I would use Thread.current + around_filter to store controller related data at thread level, and ensure it gets cleared
just before the request finishes:
class ApplicationController < ActionController::Base
around_filter :wrap_with_hack
def wrap_with_hack
# We could do this (greener solution):
# http://coderrr.wordpress.com/2008/04/10/lets-stop-polluting-the-threadcurrent-hash/
# ... but for simplicity sake:
Thread.current[:controller] = self
begin
yield
ensure
# Prevent cross request access if thread is reused later
Thread.current[:controller] = nil
end
end
end
Now the current controller instance will be avaliable globaly during the request processing through Thread.current[:controller]
If you need to access a controller variable from a model it generally means your design is wrong because a controller serves as bridge between view and model (at least in Rails), controller gets info from models, models shouldn't know anything about controllers, but if you want to do it anyway you can do it just as jeem said, but I'd rather do:
class << self
attr_accessor :current
end
instead of cattr_accessor :current
you can see why here => cattr_accessor doesn't work as it should
I can't comment directly so I'll post here: the accepted answer does not seem to be right. As #vise notes, class variables are shared across requests. So unless there's just one current account for the entire app, this won't behave as expected.
For more, see the accepted answer by #molf here: Is Rails shared-nothing or can separate requests access the same runtime variables?
I'm not sure if I understand the question exactly, but I'll take a stab.
I think if you need to access a controller instance variable from the model then you either need to make it an attribute in the model, or move your logic to the other class controller, not model.