DeadCodeTerminator

This acts like webpack's DefinePlugin with minification pass. It allows to eliminate dead code statically, which can be required by regulations.

value = if ENV['FLAG']
  :then_branch
else
  value2 = unless ENV['PRODUCTION']
    :then_branch
  else
    ENV['RUNTIME'] ? :else1 : :else2
  end
end

# returns a valid ruby code string back with statically evaluated conditions
DeadCodeTerminator.strip(string, env: { "PRODUCTION" => true, "FLAG" => false })

value = 


  value2 = 


    ENV['RUNTIME'] ? :else1 : :else2

 

Note: it keeps precise code locations (including whitespaces and line-breaks). So if you have hotfix patches from upstream - they'll be applied without conflicts. Backtrace line numbers are also preserved and can point to original code.

Other examples can be found in specs

• builtin file tree processing

The gem is available as open source under the terms of the MIT License.