Pseudolocalization

Pseudolocalization (or pseudo-localization) is a software testing method used for testing internationalization aspects of software. Instead of translating the text of the software into a foreign language, as in the process of localization, the textual elements of an application are replaced with an altered version of the original language.

Why?

Internationalization is a hard and tedious process. Different character sets, different average word length, different pluralization rules... There's a lot going on and it's impossible to test against all possible scenarios. As a side effect, most of us will simply test against one or two known languages and hope for the best. Unfortunately, this often leads to broken UI elements, texts going out of bounds, or forgotten non-translated strings making their way into a final release.

As an example, let's examine the string "Set the power switch to 0.";

Language	String	Characters	Percentage
English	Set the power switch to 0.	26 chars	-
French	Placez l'interrupteur de tension à 0.	37 chars	42% more
Spanish	Ponga el interruptor de alimentación de corriente en 0.	55 chars	112% more

It's easy to see that any hardcoded widths would likely break giving such a string. IBM suggests that on average, we should expect any English string to inflate by 30% when translating in another language.

In an attempt to ease this whole process, we created a small tool that gives you the ability to preview your product with pseudo-translations in a way that will;

Identify untranslated strings
Expand words by doubling all vowels
Use English lookalike UTF8 characters for readability

Installation

Add these lines to your application's Gemfile:

group :development do
  gem 'pseudolocalization', require: false
end

Execute:

$ bundle

Finally, in an initializer, add the following lines:

if Rails.env.development? && ENV["I18N_BACKEND"]
  case ENV["I18N_BACKEND"]
  when 'pseudolocalization'
    require 'pseudolocalization'
    I18n.backend = Pseudolocalization::I18n::Backend.new(I18n.backend)
  end
end

Usage

When working on internationalization, you can boot your server with the pseudolocalization backend to quickly identify content that doesn't go through the I18n framework.

I18N_BACKEND=pseudolocalization bundle exec rails server

Other Resources

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/Shopify/pseudolocalization.