Ruby C extension can't be 'require'd

Question

I have a ruby extension that I'm building as a gem. It has this directory structure

|-ext
  \-cowboy
    \- extconf.rb
    |- cowboy.c
|-lib
  \- cowboy.rb
  |- cowboy
    \- version.rb
|- test
  \- test_cowboy.rb

When I build it and install it, there are no errors, and 'require'ing the gem (e.g. require 'cowboy') works fine in irb.

However, when I run "ruby test/test_cowboy.rb" I get a load error from the require (it actually is complaining about "require 'cowboy/cowboy'" that lives in lib/cowboy.rb.

Does anyone know why???

Answer 1

I suspect that:

1. in irb, when you require 'cowboy', that tells rubygems to set up the load paths automatically to point to the currently installed gem dir.
2. when you run test/test_cowboy.rb it doesn't require 'cowboy'. This makes sense because during development, you don't want to load the installed version of the gem, which could be different from the code in your working dir.

I think you should create a test/test_helper.rb file that sets up the load path:

$LOAD_PATH.unshift File.expand_path('../../lib', __FILE__)

You may need to add other dirs if the compiled shared object file (.so or .bundle) isn't placed in lib.

Then in each test file (e.g. test/test_cowboy.rb), require test/test_helper.rb:

require File.expand_path('../test_helper.rb', __FILE__)

You'll need to adjust that relative path if you have subdirs. E.g. if you have a file test/shoes/spur.rb, you'd use:

require File.expand_path('../../test_helper.rb', __FILE__)