Specific Issues Upgrading Gems to Rails 4.1, RSpec 3, and Twitter Bootstrap 3.2

railsSeptember 12, 2014Dotby Justin Gordon

This article describes some tougher issues I faced when upgrading to Rails 4.1, Twitter Bootstrap 3.2 and RSpec 3. This is a companion to my related article on Rails Gem Upgrading Tips and Strategies.

Upgrade Links

If you're upgrading these specific gems, here's the must-see upgrade links.

  1. Rails 4.1: A Guide for Upgrading Ruby on Rails.
  2. RSpec 2 to RSpec 3.
  3. Twitter Bootstrap: Migrating to v3.x is essential if you're going from 2.x to 3.x.

Troubleshooting with RubyMine "Find In Path" and the Debugger

After making the require code changes to address the deprecation errors going to rspec 3, I ran into the below obscure error. This one really stumped me, due to the fact that the stack trace did not give me a specific line causing the error, and when I ran the tests individually, I didn't see any errors.

Failure/Error: Unable to find matching line from backtrace
PG::ConnectionBad: connection is closed

Here's the stack trace:

Failure/Error: Unable to find matching line from backtrace
  connection is closed
# .rvm/gems/ruby-2.1.2@bpos/gems/activerecord-4.0.8/lib/active_record/connection_adapters/postgresql_adapter.rb:589:in `reset'
# .rvm/gems/ruby-2.1.2@bpos/gems/activerecord-4.0.8/lib/active_record/connection_adapters/postgresql_adapter.rb:589:in `reconnect!'
# .rvm/gems/ruby-2.1.2@bpos/gems/activerecord-4.0.8/lib/active_record/connection_adapters/abstract_adapter.rb:377:in `verify!'
# .rvm/gems/ruby-2.1.2@bpos/gems/activerecord-4.0.8/lib/active_record/connection_adapters/abstract/connection_pool.rb:458:in `block in checkout_and_verify'
# .rvm/gems/ruby-2.1.2@bpos/gems/activesupport-4.0.8/lib/active_support/callbacks.rb:373:in `_run__2436983933572130156__checkout__callbacks'
# .rvm/gems/ruby-2.1.2@bpos/gems/activesupport-4.0.8/lib/active_support/callbacks.rb:80:in `run_callbacks'
# .rvm/gems/ruby-2.1.2@bpos/gems/activerecord-4.0.8/lib/active_record/connection_adapters/abstract/connection_pool.rb:457:in `checkout_and_verify'
# .rvm/gems/ruby-2.1.2@bpos/gems/activerecord-4.0.8/lib/active_record/connection_adapters/abstract/connection_pool.rb:358:in `block in checkout'
# .rvm/rubies/ruby-2.1.2/lib/ruby/2.1.0/monitor.rb:211:in `mon_synchronize'
# .rvm/gems/ruby-2.1.2@bpos/gems/activerecord-4.0.8/lib/active_record/connection_adapters/abstract/connection_pool.rb:355:in `checkout'
# .rvm/gems/ruby-2.1.2@bpos/gems/activerecord-4.0.8/lib/active_record/connection_adapters/abstract/connection_pool.rb:265:in `block in connection'
# .rvm/rubies/ruby-2.1.2/lib/ruby/2.1.0/monitor.rb:211:in `mon_synchronize'
# .rvm/gems/ruby-2.1.2@bpos/gems/activerecord-4.0.8/lib/active_record/connection_adapters/abstract/connection_pool.rb:264:in `connection'
# .rvm/gems/ruby-2.1.2@bpos/gems/activerecord-4.0.8/lib/active_record/connection_adapters/abstract/connection_pool.rb:546:in `retrieve_connection'
# .rvm/gems/ruby-2.1.2@bpos/gems/activerecord-4.0.8/lib/active_record/connection_handling.rb:79:in `retrieve_connection'
# .rvm/gems/ruby-2.1.2@bpos/gems/activerecord-4.0.8/lib/active_record/connection_handling.rb:53:in `connection'
# .rvm/gems/ruby-2.1.2@bpos/gems/activerecord-4.0.8/lib/active_record/fixtures.rb:450:in `create_fixtures'
# .rvm/gems/ruby-2.1.2@bpos/gems/activerecord-4.0.8/lib/active_record/fixtures.rb:899:in `load_fixtures'
# .rvm/gems/ruby-2.1.2@bpos/gems/activerecord-4.0.8/lib/active_record/fixtures.rb:870:in `setup_fixtures'
# .rvm/gems/ruby-2.1.2@bpos/gems/activerecord-4.0.8/lib/active_record/fixtures.rb:712:in `before_setup'
# .rvm/gems/ruby-2.1.2@bpos/gems/rspec-rails-3.0.2/lib/rspec/rails/adapters.rb:71:in `block (2 levels) in <module:MinitestLifecycleAdapter>'

The error was happening in a test that used resque_spec. After much searching, I began to suspect that some customization or optimization caused the issue.

RubyMine Find in Path

RubyMine's Find in Path, searching Project and Libraries, is extremely useful to getting more context around an error message. In this case, RubyMine found the error message in a C file.



Here's the C code containing the error message. The Ruby stack trace did not go this far:

 * Fetch the data pointer and check it for sanity.
PGconn *
pg_get_pgconn( VALUE self )
    PGconn *conn = pgconn_check( self );

    if ( !conn )
        rb_raise( rb_eConnectionBad, "connection is closed" );

    return conn;

And this is where in the Ruby Code that came from the stack trace:

# Disconnects from the database if already connected, and establishes a
# new connection with the database. Implementors should call super if they
# override the default implementation.
def reconnect!

RubyMine: Sometimes the Debugger Helps!

In the really troubling issue I saw below, I put in breakpoints in the connection adapter gem. I correctly guessed the cause of the error was disconnect! rather than the reconnect!

Here's a few images that show how the debugger really helped me figure out the obscure "connection is closed" error:




That is what led me to try out removing the heroku-resque gem, as I noticed that was what was closing the connections in my test runs. Removing that gem fixed my rspec errors with the upgrades.

Note, an alternative to using breakpoints in RubyMine would have been to put in a puts caller in the suspect methods of the libraries. However, one would have to remember to remove that later! I think the debugger was a good pick for this issue. If you don't use RubyMine, you might try the ruby debugger or the pry gem.

Rails 4.1 Errors

shuffle! removed from ActiveRecord::Relation

  undefined method `shuffle!' for #<ActiveRecord::Relation []>

The fix for that is to convert the relation to an array before calling shuffle. Naturally, you only want to do this with a limited set of data.

Flash changes

This one bit me: http://guides.rubyonrails.org/upgrading_ruby_on_rails.html#flash-structure-changes

I was comparing symbols when converting from the flash type to the bootstrap class. Since the keys are always normalized to strings, I changed the code to compare to strings.

It's a good idea to review all changes in that the Rails Upgrade Guide

Here's the method where I was previously comparing the flash type to symbols rather than strings:

def twitterized_type(type)
  # http://ruby.zigzo.com/2011/10/02/flash-messages-twitters-bootstrap-css-framework/
  case type
    when "alert"
    when "error"
    when "notice"
    when "success"

Upgrading Twitter Bootstrap to 3.2 from 3.0

I had this bit of code in my scss files from the old Twitter Bootstrap.

// Sprite icons path
// -------------------------
$iconSpritePath: asset-url("glyphicons-halflings.png");
$iconWhiteSpritePath: asset-url("glyphicons-halflings-white.png");

Since I'm using the new 3.2 version of bootstrap-sass, I needed to do the following, per the details here:

  1. Delete the glyphicons-halflings.png and glyphicons-halflings-white.png files.
  2. Remove the reference shown above to the $iconSpritePath
  3. Add this line to my application.css.scss
@import "bootstrap-sprockets";
  1. Add this line to the Gemfile:
gem 'autoprefixer-rails'

Please let me know if this article helped you or if I missed anything!



Closing Remark

Could your team use some help with topics like this and others covered by ShakaCode's blog and open source? We specialize in optimizing Rails applications, especially those with advanced JavaScript frontends, like React. We can also help you optimize your CI processes with lower costs and faster, more reliable tests. Scraping web data and lowering infrastructure costs are two other areas of specialization. Feel free to reach out to ShakaCode's CEO, Justin Gordon, at justin@shakacode.com or schedule an appointment to discuss how ShakaCode can help your project!
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