76 lines
2.4 KiB
Ruby
76 lines
2.4 KiB
Ruby
# frozen_string_literal: true
|
|
##
|
|
# RubyGems adds the #gem method to allow activation of specific gem versions
|
|
# and overrides the #require method on Kernel to make gems appear as if they
|
|
# live on the <code>$LOAD_PATH</code>. See the documentation of these methods
|
|
# for further detail.
|
|
|
|
module Kernel
|
|
|
|
##
|
|
# Use Kernel#gem to activate a specific version of +gem_name+.
|
|
#
|
|
# +requirements+ is a list of version requirements that the
|
|
# specified gem must match, most commonly "= example.version.number". See
|
|
# Gem::Requirement for how to specify a version requirement.
|
|
#
|
|
# If you will be activating the latest version of a gem, there is no need to
|
|
# call Kernel#gem, Kernel#require will do the right thing for you.
|
|
#
|
|
# Kernel#gem returns true if the gem was activated, otherwise false. If the
|
|
# gem could not be found, didn't match the version requirements, or a
|
|
# different version was already activated, an exception will be raised.
|
|
#
|
|
# Kernel#gem should be called *before* any require statements (otherwise
|
|
# RubyGems may load a conflicting library version).
|
|
#
|
|
# Kernel#gem only loads prerelease versions when prerelease +requirements+
|
|
# are given:
|
|
#
|
|
# gem 'rake', '>= 1.1.a', '< 2'
|
|
#
|
|
# In older RubyGems versions, the environment variable GEM_SKIP could be
|
|
# used to skip activation of specified gems, for example to test out changes
|
|
# that haven't been installed yet. Now RubyGems defers to -I and the
|
|
# RUBYLIB environment variable to skip activation of a gem.
|
|
#
|
|
# Example:
|
|
#
|
|
# GEM_SKIP=libA:libB ruby -I../libA -I../libB ./mycode.rb
|
|
|
|
def gem(gem_name, *requirements) # :doc:
|
|
skip_list = (ENV['GEM_SKIP'] || "").split(/:/)
|
|
raise Gem::LoadError, "skipping #{gem_name}" if skip_list.include? gem_name
|
|
|
|
if gem_name.kind_of? Gem::Dependency
|
|
unless Gem::Deprecate.skip
|
|
warn "#{Gem.location_of_caller.join ':'}:Warning: Kernel.gem no longer "\
|
|
"accepts a Gem::Dependency object, please pass the name "\
|
|
"and requirements directly"
|
|
end
|
|
|
|
requirements = gem_name.requirement
|
|
gem_name = gem_name.name
|
|
end
|
|
|
|
dep = Gem::Dependency.new(gem_name, *requirements)
|
|
|
|
loaded = Gem.loaded_specs[gem_name]
|
|
|
|
return false if loaded && dep.matches_spec?(loaded)
|
|
|
|
spec = dep.to_spec
|
|
|
|
if spec
|
|
if Gem::LOADED_SPECS_MUTEX.owned?
|
|
spec.activate
|
|
else
|
|
Gem::LOADED_SPECS_MUTEX.synchronize { spec.activate }
|
|
end
|
|
end
|
|
end
|
|
|
|
private :gem
|
|
|
|
end
|