Understanding Ruby's load paths

Question

I'm a little confused about why my project can't load the files it needs, it's a really simple project tree:

processor/   bin/   lib/     processor.rb     processor/       mapper.rb       reducer.rb 

and my processor.rb file looks like

require 'processor/mapper' require 'processor/reducer'  class Processor  end 

And just for testing it that file mapper looks like:

class Mapper   def run     puts "running map"   end end 

But running ruby lib/processor.rb results in:

<internal:lib/rubygems/custom_require>:29:in `require': no such file to load -- processor/mapper (LoadError)     from <internal:lib/rubygems/custom_require>:29:in `require'     from lib/processor.rb:3:in `<class:Processor>'     from lib/processor.rb:2:in `<main>'     

Answer 1

Ruby's $LOAD_PATH will not include your lib directory by default (even though that's where the file you're running is located).

You can either tell the ruby interpreter to include it:

ruby -Ilib lib/processor.rb 

Or you can add the lib folder to the load path:

$LOAD_PATH.unshift(File.dirname(__FILE__)) require  'processor/mapper' ...