LoadError when creating ruby gem

Question

I'm trying to create my first gem and here's its structure:

riverbattle
├── lib
│   ├── riverbattle
│   │   ├── base.rb
│   │   ├── colorful.rb
│   │   ├── computer.rb
│   │   ├── constants.rb
│   │   ├── exit_error.rb
│   │   ├── field.rb
│   │   ├── game.rb
│   │   ├── human.rb
│   │   ├── invalid_move_error.rb
│   │   ├── move.rb
│   │   ├── player.rb
│   │   ├── version.rb
│   │   └── victory_error.rb
│   └── riverbattle.rb
└── riverbattle.gemspec

When I am in the directory rivarbattle/lib/riverbattle and I run the command ruby base.rb, everything starts working as it should be.

The file base.rb is here:

require './game'
game = Game.new.start

But when I try to run it from the lib directory using command ruby riverbattle.rb, it fails with the following error:

/home/denis/.rvm/rubies/ruby-2.2.1/lib/ruby/site_ruby/2.2.0/rubygems/core_ext/kernel_require.rb:54:in require': cannot load such file -- riverbattle/base (LoadError) from /home/denis/.rvm/rubies/ruby-2.2.1/lib/ruby/site_ruby/2.2.0/rubygems/core_ext/kernel_require.rb:54:inrequire' from riverbattle.rb:1:in `'

The file lib/riverbattle.rb look like this:

require 'riverbattle/base'

Despite the fact that the load fails I tried to build the gem with the following .gemspec file:

# -*- encoding: utf-8 -*-
lib = File.expand_path('../lib', __FILE__)
$LOAD_PATH.unshift(lib) unless $LOAD_PATH.include?(lib)
require "riverbattle/version"

Gem::Specification.new do |s|
    s.name          = 'riverbattle'
    s.date          = '2015-07-04'
    s.summary       = 'Enjoy the game!'
    s.description   = 'A small simple game called the Riverbattle'
    s.platform      = Gem::Platform::RUBY
    s.version       = '0.1.0'
    s.authors       = ["Denis Yakovenko"]
    s.email         = ["[e-mail]"]
    s.require_paths = ["lib"]
    s.license       = "MIT"
end

After the successful build, I went to irb and tried require 'riverbattle' and got the error:

LoadError: cannot load such file -- riverbattle

from /home/denis/.rvm/rubies/ruby-2.2.1/lib/ruby/site_ruby/2.2.0/rubygems/core_ext/kernel_require.rb:54:in require' from /home/denis/.rvm/rubies/ruby-2.2.1/lib/ruby/site_ruby/2.2.0/rubygems/core_ext/kernel_require.rb:54:inrequire' from (irb):1 from /home/denis/.rvm/rubies/ruby-2.2.1/bin/irb:11:in `'

---

1) What am I doing wrong with require that the files from different directories cannot be loaded? (After looking through stackoverflow questions I figured out that this is some problem with $LOAD_PATH, but I couldn't find out how to fix the code. BTW, such require LoadErrors happen quite often for some reason and then I try to use require_relative and sometimes it helps)

2) When I tried to lauch the gem in irb, the error was raised because of those initial problems with require, right? Or something else is wrong?

3) If I want to add tests folder to the gem, can I just add the folder tests to the root directory and copy all the rspec files there?

UPDATE

When I tried to run RUBYLIB="." ruby riverbattle.rb in the terminal in the lib folder, it gave me this:

RUBYLIB="." ruby riverbattle.rb /home/denis/.rvm/rubies/ruby-2.2.1/lib/ruby/site_ruby/2.2.0/rubygems/core_ext/kernel_require.rb:54:in require': cannot load such file -- ./field (LoadError) from /home/denis/.rvm/rubies/ruby-2.2.1/lib/ruby/site_ruby/2.2.0/rubygems/core_ext/kernel_require.rb:54:inrequire' from /home/denis/WEB/Bursa/riverbattle/lib/riverbattle/game.rb:1:in <top (required)>' from /home/denis/.rvm/rubies/ruby-2.2.1/lib/ruby/site_ruby/2.2.0/rubygems/core_ext/kernel_require.rb:54:inrequire' from /home/denis/.rvm/rubies/ruby-2.2.1/lib/ruby/site_ruby/2.2.0/rubygems/core_ext/kernel_require.rb:54:in require' from /home/denis/WEB/Bursa/riverbattle/lib/riverbattle/base.rb:1:in ' from /home/denis/.rvm/rubies/ruby-2.2.1/lib/ruby/site_ruby/2.2.0/rubygems/core_ext/kernel_require.rb:54:in require' from /home/denis/.rvm/rubies/ruby-2.2.1/lib/ruby/site_ruby/2.2.0/rubygems/core_ext/kernel_require.rb:54:inrequire' from riverbattle.rb:1:in `'

Answer 1

1. #require tries to load an absolute path, and if it fails it loads from $:, to add your current directory run the script like this (bash, otherwise use apropriate method to define environment variables for your shell):

RUBYLIB="." ruby riverbattle.rb

In your base.rb require as follows:

require 'riverbattle/game'

2. see #UPD section

3. why wouldn't you? (what's your specific problem with this?)

#UPD

The 2nd issue is because you miss #files in your gem specification, no files are included in your gem file, add something like this:

s.files = Dir['lib/*.rb'] + Dir['lib/riverbattle/*.rb']

#UPD2

Just to summarize here is working setup for your gem.