chromedriver-helper gem in Gemfile might break you selenium tests (of other projects)

Summary: Don't add chromedriver-helper to the Gemfile

  • the executables might break your tests in projects where chromedriver-helper is not in the Gemfile
  • developers with different chrome versions will have problems using the same chromedriver-helper version

Background

If you install the chromedriver-helper gem, but don't have it in you Gemfile, your selenium tests might fail with:

Selenium::WebDriver::Error::WebDriverError: unable to connect to chromedriver 127.0.0.1:9515

The reason is that chromedriver-helper ov...

Edge Rider: Power tools for ActiveRecord scopes

In our continued quest to extract proven code snippets from makandropedia into tested and upgradable gems, we have released Edge Rider.

Edge Rider was created with two intents:

  1. Provides a number of utility methods to facilitate hardcore work with scopes.
  2. Provide a stable API for working with scopes across multiple versions of Rails, since Rails has a tradition of breaking details of its scope API every other release.

The gem bundles multiple patches and initializers we've been using for hard...

Installation of therubyracer fails with "undefined method `include_path'"

Today I ran into trouble installing therubyracer on Ruby 1.8. The installation failed with

*** extconf.rb failed ***
Could not create Makefile due to some reason, probably lack of
necessary libraries and/or headers.  Check the mkmf.log file for more
details.  You may need configuration options.

Provided configuration options:
    --with-opt-dir
    --without-opt-dir
    --with-opt-include
    --without-opt-include=${opt-dir}/include
    --with-opt-lib
    --without-opt-lib=${opt-dir}/lib
    --with-make-prog
   ...

Create autocompletion dropdown for Cucumber paths in Textmate

Ever wanted autocompletion for paths from paths.rb in Cucumber? This card lets you write your steps like this:

When I go to path *press tab now* # path is replaced with a list of all known Cucumber paths

This is how you do it

(key shortcuts apply for TextMate2)

  1. Open the bundle editor (ctrl + alt +  + B)

  2. Create a new Item ( + N), select "Command"

  3. Paste this:
    ^
    #!/usr/bin/env ruby -wKU
    require File.join(ENV['TM_SUPPORT_PATH'], 'lib', 'ui.rb')

    cucumber_paths = File.join ENV['TM_PROJECT_DIRECTORY'], 'features'...

Resque + God + Capistrano

Attached is a working config to deploy an application with Capistrano that needs to monitor Resque workers with God.

God will run as the deployment user, no need to register it as a system service.

Put this into your config/deploy.rb:

namespace :god do
  def god_is_running
    !capture("#{god_command} status >/dev/null 2>/dev/null || echo 'not running'").start_with?('not running')
  end

  def god_command

...

Net::SSH::Exception: could not settle on encryption_client algorithm

TL;DR: Update the 'net-ssh' gem by adding to your Gemfile:

gem 'net-ssh', '=2.9.1'

Now run bundle update net-ssh. It has no dependencies so it shouldn't update other gems.

If you're using Ruby 1.8.7 and want to update net-ssh to a version > 2.9.1 you also need to add this to your gemfile:

gem 'backports', :require => false

... and in your deploy.rb add this:

require 'backports/1.9.2/array/select' 

Background

You propably have an older version of Capistrano and thereby an older version of `n...

Exclusive cronjobs with flock and whenever

I had a very frequent cronjob that in rare cases could be relatively slow. To avoid multiple instances of this cronjob running in parallel, I decided to use flock to ensure that only one instance could run at a time.

flock works by acquiring a lock to a file, and if it can do so running a command. In order not to wait but simply give up when the file is locked, you can add -n:

flock /tmp/my.task.lock -n -c "bin/my-long-running-job"

Using whenever, and since this was a rake task, the follo...

Disabling Spring when debugging

Spring is a Rails application preloader. When debugging e.g. the rails gem, you'll be wondering why your raise, puts or debugger debugging statements have no effect. That's because Spring preloads and caches your application once and all consecutive calls to it will not see any changes in your debugged gem.

Howto

Disable spring with export DISABLE_SPRING=1 in your terminal. That will keep Spring at bay in that terminal session.

In Ruby, [you can only write environment variables that subproc...

Adjust cron jobs to allow full backtraces for rake tasks

As we get an exception notification, when a cron job fails, we wish to have the full backtrace in this mail. A rake task doesn't output the full backtrace by default, so you need the --backtrace option.

Trigger

You will find fail mails with a shortened backtrace

#[...]
Tasks: TOP => some_namespace:some_task
(See full trace by running task with --trace)

What rake wants from you
Running the rake task like rake some_namespace:some_task --backtrace

How this works with whenever
Define a own job_type and use it for r...

Accessing Rails config in webpack(er)

It is possible to access Rails config (for example secrets) from within your webpack bundles, thanks to rails-erb-loader. When using webpacker, the setup is like this:

  1. Install rails-erb-loader:

    yarn add rails-erb-loader
    
  2. Add this to your config/webpacker/environment.js:

    environment.loaders.prepend('erb', {
      test: /\.erb$/,
      enforce: 'pre',
      use: [{
        loader: 'rails-erb-loader',
      }]
    })
    
  3. Start using erb. For examp...

Fix: "undefined method `bytesize' for #<Array>"

I believe that when WEBrick has trouble bringing up your Rails application, the WEBrick component that is supposed to print you a pretty error message has a bug and sometimes fails with this message:

"undefined method `bytesize' for #<Array>"

Starting the application in Passenger gave me a stacktrace in log/development.log that pointed to the actual problem.

Possible causes discovered by looking at the logs
-----------------------------------------------------...

How to checkout submodules in Gitlab CI

Accessing other repositories in Gitlab CI is not straight forward, since the access rights of the current pipeline might not be sufficient enough.

One approach is to use project access tokens and clone the repositories via HTTPS.

  • Create a project access token for all submodules you want to have access to with the setting read_repository
  • Add the secrets as environment variable to the main project you want to have access to submodules:
    • Protected false ...

Sending errors to sentry from development

For the initial setup or changes in the sentry reporting it might be useful to enabled reporting of sentry in development. Don't commit these changes and prefer to report to the staging environment. As other developers might be confused of these errors try to given them a proper message and delete them afterwards.


  1. Add config.raven_dsn = 'your-dns' in config/environments/development.rb.
  2. Add development to existing environments in the Raven.configure block: config.environments = ['development', 'staging', 'production'].
  3. ...

Cucumber: How to find unused step definitions

Cucumber has an output format that prints step definitions only. You can use this to find unused ones:

  1. Temporarily add require_relative 'env' to the top of the first file in features/support. --dry-run makes Cucumber skip loading env.rb.
  2. Open a really wide terminal window.
  3. bundle exec cucumber --dry-run --format stepdefs | grep -B1 'NOT MATCHED' --no-group-separator | grep features/step_definitions

This will print all unused step definitions from your project – however, the result will include false positives. Step...

Gemspecs must not list the same gem as both runtime and development dependency

When you're developing a gem, never list the same dependency as both runtime and development dependency in your .gemspec.

So don't do this:

spec.add_dependency 'activesupport'
spec.add_development_dependency 'activesupport', '~> 2.3'

If you do this, your gemspec will not validate and modern versions of Bundler will silently ignore it. This leads to errors like:

Could not find your-gem-0.1.2 in any of the sources

What to do instead

If you want to freeze a different version of a dependency for your t...

"cannot load such file -- nokogiri/nokogiri" (or any other Gem with native extensions on rvm and Ruby >= 2)

After running bundler / gem install I could not load nokogiri lately. It died with cannot load such file -- nokogiri/nokogiri.
This is not a problem of the gem but is due to a broken native extensions installation routine.

When installing nokogiri manually and with verbose output by using gem install -V nokogiri -v 1.5.6, you can see the problem scrolling by when the native extension is built:

/usr/bin//install -c -m 0755 nokogiri.so /home/thomas/.rvm/gems/ruby-2.0.0-p247/gems/nokogiri-1.5.6/lib/home/thomas/.rvm/rubies/ruby-2.0.0-p...

Shell script to deploy changes to production and not shoot yourself in the foot

Geordi, our collection of command line tools, has been extended by another command deploy-to-production. This script encapsulates the following workflow:

  • Pull the production branch.
  • Show which commits from the master would make it to production with this deploy.
  • Ask if you want to proceed.
  • If yes, merge the master into the production branch, push and deploy with bundle exec cap production deploy:migrations

The script will ask you for the names of your master branch, production branch an...

How to upgrade Cucumber on Rails 3+

  1. Run bundle update cucumber capybara cucumber-rails to update to the newest versions.

  2. Backup your features/support/path.rb to be able to add your own paths again after the cucumber installation script in step 4.

  3. Backup your features/support/env.rb file to be able to reintegrate parts like your blueprints setup:

    ENV["RAILS_ENV"] ||= "cucumber"
    require File.expand_path(File.dirname(__FILE__) + '/../../config/environment')
    require 'spec/support/blueprints'
    
  4. Run `$ rails generate cucumber:install --capyba...

PSA: Dont allow private gems to be pushed to rubygems.org

If you make a gem with Bundler, you will get a rake release task that will instantly publish your gem to rubygems.org for all the world to admire. For private gems this is very bad.

To make sure this cannot happen, rubygems 2.2+ allows you to restrict eligible push hosts:

Gem::Specification.new 'my_gem', '1.0' do |s|
  # ...
  s.metadata['allowed_push_host'] = 'https://gems.my-company.example'
end

In case you already messed up, [follow these instructions to get your gem removed](http://help.rubygems.org/kb/rubygems/removing-an-a...

Parallel cucumber: How to pass in cucumber arguments

Here is an example with the --tags option. You need to wrap them inside --cucumber-options option of parallel_cucumber.

DISPLAY=:17 bundle exec parallel_cucumber --cucumber-options '--tags @solo' features

See more details in the docs.

Zeus promises to make rails development faster

I am talking about development speed. When your application starts growing and you start adding gems, it starts to take really long to start up, be it the server, console or just running a single spec.

Zeus is smart, you don’t have to put it in your Gemfile or run it with Bundler, all you need to do is create a JSON config file via zeus init and then start the server zeus start.

After that, you’re ready to go, all you need to do is prefix every command with zeus. That means rails server becomes zeus server, `rails console...

Sunspot and Solr on Tomcat: Trouble with Umlauts

We experienced problems with Sunspot and Solr on Tomcat: Umlauts (ä, ö, ü) were not correctly handled on Tomcat while everything was okay on the local development machines (your local Sunspot service you start with the sunspot:solr:run task is based on Jetty).

We use a stemmer that reduces "Sänger" to "sang" and "Sanger" to "sang" as well.
Though, results for "Sänger" where empty on Tomcat.

This is due to a UTF-8 bug in RSolr (see Github for some discussion on that).
The bug is fixed in a ...

Geordi 1.5.1 released

  • Improve geordi cucumber: Only attempt @solo run when the specified files contain the @solo tag, skip @solo run if any filename is passed with a line number (e.g. features/example.feature:3)
  • Improve geordi deploy: Find stages by their prefix (e.g. s -> staging, m -> makandra), bundle if needed, check the selected stage exists
  • Improve geordi server: Takes port as argument (e.g. geordi ser 3001), option --public (-P) starts the server with -b 0.0.0.0 to make it accessible from other machines in the local network, e.g. ...