Bundler.require not loading .gemspec dependencies

[jch]

I'm not sure if this is intentional behavior, but from this documentation, I expected that Bundler.require :default would also require the runtime dependencies specified in .gemspec. I've created a demo gem showing this.

# gemspec
Gem::Specification.new do |gem|
  # snip
  gem.add_dependency 'rack'
end

# Gemfile
source 'https://rubygems.org'

# Specify your gem's dependencies in bundler-issue.gemspec
gemspec

# test.rb
require 'bundler'
Bundler.require :default  # <-- I expected this to load dependencies in from the gemspec

puts "Dependency loaded: " + defined?(Rack).inspect

If I explicitly require rack, it works as expected, and Gemfile.lock lists rack as expected.

[indirect]

Gems must load their own dependencies. If they don't, they are no longer functional Rubygems.

On Jul 6, 2012, at 5:05 PM, Jerry Cheungreply@reply.github.com wrote:

I'm not sure if this is intentional behavior, but from this documentation, I expected that Bundler.require :default would also require the runtime dependencies specified in .gemspec. I've created a demo gem showing this.

# gemspec
Gem::Specification.new do |gem|
 # snip
 gem.add_dependency 'rack'
end

# Gemfile
source 'https://rubygems.org'

# Specify your gem's dependencies in bundler-issue.gemspec
gemspec

# test.rb
require 'bundler'
Bundler.require :default  # <-- I expected this to load dependencies in from the gemspec

puts "Dependency loaded: " + defined?(Rack).inspect

If I explicitly require rack, it works as expected, and Gemfile.lock lists rack as expected.

---

Reply to this email directly or view it on GitHub:
#2018

[ghost]

Additional note: Bundler.require will only require those gems that are listed in the Gemfile. Dependencies (rack in this case`) must be loaded manually, as @indirect already said.

[jch]

Thanks for the clarification!

[ianfixes]

Gems must load their own dependencies.

Can you explain what this means, to someone who is unfamiliar with this process?

[indirect]

@ifreecarve no problem. Gems are not able to use Bundler, so they should simply require the libraries they need.

[ianfixes]

By this you mean that in whatever ruby source files are contained in the gem, you say require 'some_library'? And bundler uses this to determine/download dependencies when you bundle install?

(I was able to solve the problem I was having, but I have no idea how.)

[indirect]

Not exactly. When you create a gem, list any other gems you depend on in your gemspec. Then, inside the code of your gem, require those gems. So, if your gem depends on Rack, you would add a line like s.add_runtime_dependency "rack", "~> 1.2" to your gemspec, and then a line like require "rack" to your gem code.

Bundler will use the gemspec to know what to install and add to the load path; your gem will then require it and be able to use it.

On Wed, May 20, 2015 at 12:06 PM, Ian notifications@github.com wrote:

By this you mean that in whatever ruby source files are contained in the gem, you say require 'some_library'? And bundler uses this to determine/download dependencies when you bundle install?

(I was able to solve the problem I was having, but I have no idea how.)

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#2018 (comment)

[ianfixes]

Hmm... that's what I was doing. Bundler seemed to be ignoring what i put in s.add_runtime_dependency, which is why I asked. I had tried a variety of things, and although it works now I'm not sure what fixed it.

[maschwenk]

@indirect would this potentially change now that bundler is part of Ruby std lib?

[colby-swandale]

No, this behavior is not changing.