Rails 5 deprecation warning and adding code to initializers? - ruby-on-rails

To which initializer file should I add the desired line of code?
I'm getting the following deprecation warning.
DEPRECATION WARNING: Time columns will become time zone aware in Rails 5.1. This still causes Strings to be parsed as if they were in Time.zone,
and Times to be converted to Time.zone.
To keep the old behavior, you must add the following to your initializer:
config.active_record.time_zone_aware_types = [:datetime]
To silence this deprecation warning, add the following:
config.active_record.time_zone_aware_types = [:datetime, :time]
I'm a rails newbie, I just want to follow best practice. Thanks!

add to config/application.rb inside class Application < Rails::Application this line:
config.active_record.time_zone_aware_types = [:datetime, :time]

create file /config/initializers/time_zone_aware_types.rb
then add next line to the file
Rails.application.config.active_record.time_zone_aware_types = [:datetime, :time]

Related

Specifying parent controller in rails_admin results in deprecation warning

I noticed in my rails 6 project that adding the following to config/initializers/rails_admin.rb results in a deprecation warning:
RailsAdmin.config do |config|
config.parent_controller = ApplicationController.to_s
# ...
Warning:
DEPRECATION WARNING: Initialization autoloaded the constants ApplicationHelper, AboutHelper, GroupHelper, MapHelper, DeviseHelper, ActionText::ContentHelper, and ActionText::TagHelper.
Being able to do this is deprecated. Autoloading during initialization is going
to be an error condition in future versions of Rails.
Reloading does not reboot the application, and therefore code executed during
initialization does not run again. So, if you reload ApplicationHelper, for example,
the expected changes won't be reflected in that stale Module object.
These autoloaded constants have been unloaded.
Please, check the "Autoloading and Reloading Constants" guide for solutions.
(called from <main> at /opt/app/config/environment.rb:5)
One workaround for this is to simply use "ApplicationController" instead of ApplicationController.to_s, but is there a way to do the latter approach without this deprecation warning?
yes, you are right
# Which class should be used for the controllers
config.parent_controller = '::ApplicationAdminController'
here the issue in the library issue_link

Zeitwerk error on devise mailer in production environment

I have Rails 6, my preview class located in
mailer/previews/devise_mailer_preview.rb:
class DeviseMailerPreview < ActionMailer::Preview
...
end
And when I run application locally, everything is going fine, I can see my email previews on http://localhost:3000/rails/mailers/devise_mailer/confirmation_instructions address. But now Im trying to deploy application on server, and found that when I run bundle exec rails c production, I got the error:
/home/deploy/.rbenv/versions/2.6.5/lib/ruby/gems/2.6.0/gems/zeitwerk-2.3.0/lib/zeitwerk/loader/callbacks.rb:17:in
`on_file_autoloaded': expected file
/home/deploy/project/releases/20200627024908/app/mailer/previews/devise_mailer_preview.rb
to define constant Previews::DeviseMailerPreview, but didn't
(Zeitwerk::NameError)
After that I've checked locally RAILS_ENV=production rails c, and got same.
If I will rename DeviseMailerPreview class to Previews::DeviseMailerPreview, it will be broken and I cannot see emails on development, because Rails 6, accordingly to docs, expect exactly that name.
More of that, I've found in this article, that zeitwerk can be configured with autoload_paths param to avoid ruby's NameError. I found that I have it my config/application.rb:
config.load_defaults 6.0
Anyway I tried to add same row in my config/environments/production.rb file, but it didn't help.
What am I doing wrong and how can I fix it? Thanks in advance!
Add preview_path to the autoload_paths and zeitwerk will expect DeviseMailerPreview constant to be defined.
# development.rb
config.action_mailer.preview_path = Rails.root.join("app/mailers/previews")
# application.rb
config.autoload_paths << Rails.root.join("app/mailers/previews")
Your Mailer preview file is located in mailer/previews/devise_mailer_preview.rb, so I'm assuming it's full path is app/mailer/previews/devise_mailer_preview.rb
The docs says
In the above example, the preview class for UserMailer should be named UserMailerPreview and located in test/mailers/previews/user_mailer_preview.rb
So put your devise_mailer_preview.rb file to test/mailers/previews/devise_mailer_preview.rb
or in your config/application.rb add this line and restart:
config.action_mailer.preview_path = "#{Rails.root}/app/mailers/previews"
Actually the answer was in the docs itself.
In Rails 6, previews are added to the autoload paths only if options.show_previews is true, which is not by default in the production environment. See the source code here.
The reason for this is that previews are supposed to be an aid for development, and they are generally not something you want to be able to look at in production.
However, you can set that flag to true in production if you want.
There's another derivative: By storing the previews under app/mailers, Rails is going to eager load them because app/mailers is in the autoload paths. If app/mailers/previews is not in the autoload paths, eager loading will fail due to the namespace mismatch. Either you have them enabled in all environments, or else is better to have them in a separate location, like the default.

Rails unable to autoload constant from file despite being defined in that file

This is a tricky one to explain. I have a module in another module namespace like so:
# app/models/points/calculator.rb
module Points
module Calculator
def self.included(base)
base.send(:include, CommonMethods)
base.send(:include, "Points::Calculator::#{base}Methods".constantize)
end
end
end
So then in other classes all I need to do is:
class User
include Points::Calculator
end
I've specified this directory in application.rb to be autoloadable...(even though i think rails recurses through models...)
config.autoload_paths += Dir[ Rails.root.join('app', 'models', "points") ]
In development env, everything works fine. When running tests(and production env), I get the following error:
Unable to autoload constant Points::Calculator, expected /Users/pete/work/recognize/app/models/points/calculator.rb to define it (LoadError)
I actually followed the advice here to fix the problem: Stop Rails from unloading a module in development mode by explicitly requiring calculator.rb in application.rb.
However, why is this happening??
I stuck some debug output in ActiveSupport's dependencies.rb file and noticed that this file is being required twice. The first time its required I can see that the constant is indeed loaded.
But the 2nd time its required the constant has been unloaded as far as Rails can tell, but when the actual require is called, ruby returns false because ruby knows its already required it. Then Rails throws the "unable to autoload constant" error because the constant still isn't present and ruby didn't "re-require" the file.
Can anyone shed light on why this might be happening?
Rails augments the constant lookup mechanism of ruby.
Constant lookup in Ruby:
Similar to method missing, a Module#constant-missing is invoked when a reference to a constant fails to be resolved. When we refer to a constant in a given lexical scope, that constant is searched for in:
Each entry in Module.nesting
Each entry in Module.nesting.first.ancestors
Each entry in Object.ancestors if Module.nesting.first is nil or a module.
When we refer to a constant, Ruby first attempts to find it according to this built-in lookup rules.
When ruby fails to find... rails kicks in, and using its own lookup convention and its knowledge about which constants have already been loaded (by ruby), Rails overrides Module#const_missing to load missing constants without the need for explicit require calls by the programmer.
Its own lookup convention?
Contrasting Ruby’s autoload (which requires the location of each autoloaded constant to be specified in advance) rails following a convention that maps constants to file names.
Points::Calculator # =>points/calculator.rb
Now for the constant Points::Calculator, rails searches this file path (ie 'points/calculator.rb') within the autoload paths, defined by the autoload_paths configuration.
In this case, rails searched for file path points/calculator in its autoloaded paths, but fails to find file and hence this error/warning is shown.
This answer is an abstract from this Urbanautomation blog.
Edit:
I wrote a blog about Zeitwerk, the new code reloader in Rails. Check it out at -> https://blog.bigbinary.com/2019/10/08/rails-6-introduces-new-code-loader-called-zeitwerk.html
If someone is having this issue in rails 6 which has zeitwerk autoloader,
Change ruby constant lookup back to classic in your application.rb
# config/application.rb
#...
config.autoloader = :classic
#...
Read more details here Rails Official Guides
Calculator should be a class to be autoloaded correctly
module Points
class Calculator
...
end
end

Deprecation warning mocks won't be added automatically to load paths

After upgrading to Rails 3 I get this deprecation warning:
DEPRECATION WARNING: "Rails.root/test/mocks/test" won't be added automatically to load paths anymore in future releases.
So how should this be implemted in Rails 3?
Rails just checks for the existence of the mocks/test directory and spits out that warning if it exists. Here is what the code looks like from rails/railties/lib/rails/application/configuration.rb:
if File.exists?("#{root}/test/mocks/#{Rails.env}")
ActiveSupport::Deprecation.warn "\"RAILS_ROOT/test/mocks/#{Rails.env}\" won't be added " <<
"automatically to load paths anymore in future releases"
paths.mocks_path "test/mocks", :load_path => true, :glob => Rails.env
end
So it looks like this message will remain until they deprecate it.
If you need this path in your load path in the future, I think you just do something like this in config/application.rb (notice the comments taken directly from the config/application.rb template):
# Add additional load paths for your own custom dirs
config.load_paths += %W( #{config.root}/test/mocks/#{Rails.env} )
I haven't tried it but this should help!

Silencing Deprecation warnings in Rails 3

Can anyone tell me how to silence deprecation warinings in Rails 3?
I have a few situations where it is throwing false positives. Namely using - for loops in haml and f.error_messages from the dynamic_form plugin.
Thanks
To silence all deprecation warnings you can do:
ActiveSupport::Deprecation.silenced = true
This could be placed in an initializer or in the environment file for a specific environment (e.g. to silence only in production for example.)
Or for a specific section of code, enclose it in a block:
ActiveSupport::Deprecation.silence do
# no warnings for any use of deprecated methods here
end
This works for both Rails 3 & 4.
The accepted answer didn't work for me with Rails 3.2.12. Placing it in either the environments/production.rb or an initializer still outputted the warnings. I had to put it in my config/environment.rb file before the application was initialized:
# Load the rails application
require File.expand_path('../application', __FILE__)
::ActiveSupport::Deprecation.silenced = true if Rails.env.production?
# Initialize the rails application
Notices::Application.initialize!
Ryan Daigle wrote an article about this, in which he also showed how you can intercept the deprecation warning and do something else with it, like send it to a log file:
ActiveSupport::Deprecation.behavior = Proc.new { |msg, stack| MyLogger.warn(msg) }
http://ryandaigle.com/articles/2006/12/4/how-to-turn-deprecation-warnings-off-in-rails

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