Auto merge of #4320 - bundler:seg-with-rubygems, r=segiddins

Add helper script for running with particular rubygems versions

\c @indirect

4 files changed, 48 insertions, 9 deletions

diff --git a/bin/rake b/bin/rake
index ccf7cbeedc..29b6d6f4aa 100755
--- a/bin/rake
+++ b/bin/rake
@@ -1,6 +1,8 @@
 #!/usr/bin/env ruby
 # frozen_string_literal: true
 
+load File.expand_path("../with_rubygems", __FILE__) if ENV["RGV"]
+
 require "rubygems"
 
 bundler_spec = Gem::Specification.load(File.expand_path("../../bundler.gemspec", __FILE__))
@@ -12,8 +14,6 @@ bundler_spec.dependencies.each do |dep|
   end
 end
 
-Gem::Specification.unresolved_deps.each do |_name, dep|
-  gem dep.name, *dep.requirement
-end
+Gem.finish_resolve if Gem.respond_to?(:finish_resolve)
 
 load Gem.bin_path("rake", "rake")
diff --git a/bin/rspec b/bin/rspec
index 404da15056..388fe57382 100755
--- a/bin/rspec
+++ b/bin/rspec
@@ -1,6 +1,8 @@
 #!/usr/bin/env ruby
 # frozen_string_literal: true
 
+load File.expand_path("../with_rubygems", __FILE__) if ENV["RGV"]
+
 require "rubygems"
 
 bundler_spec = Gem::Specification.load(File.expand_path("../../bundler.gemspec", __FILE__))
@@ -8,8 +10,6 @@ bundler_spec.dependencies.each do |dep|
   gem dep.name, dep.requirement.to_s
 end
 
-Gem::Specification.unresolved_deps.each do |_name, dep|
-  gem dep.name, *dep.requirement
-end
+Gem.finish_resolve if Gem.respond_to?(:finish_resolve)
 
 load Gem.bin_path("rspec-core", "rspec")
diff --git a/bin/rubocop b/bin/rubocop
index bc81f5cc88..01840861cc 100755
--- a/bin/rubocop
+++ b/bin/rubocop
@@ -1,6 +1,8 @@
 #!/usr/bin/env ruby
 # frozen_string_literal: true
 
+load File.expand_path("../with_rubygems", __FILE__) if ENV["RGV"]
+
 require "rubygems"
 
 bundler_spec = Gem::Specification.load(File.expand_path("../../bundler.gemspec", __FILE__))
@@ -10,8 +12,6 @@ end
 
 gem "rubocop", "= 0.37.1"
 
-Gem::Specification.unresolved_deps.each do |_name, dep|
-  gem dep.name, *dep.requirement
-end
+Gem.finish_resolve if Gem.respond_to?(:finish_resolve)
 
 load Gem.bin_path("rubocop", "rubocop")
diff --git a/bin/with_rubygems b/bin/with_rubygems
new file mode 100755
index 0000000000..d16c289822
--- /dev/null
+++ b/bin/with_rubygems
@@ -0,0 +1,39 @@
+#!/usr/bin/env ruby
+# frozen_string_literal: true
+
+require "pathname"
+
+def run(*cmd)
+  return if system(*cmd)
+  raise "Running `#{cmd.join(" ")}` failed"
+end
+
+version = ENV.delete("RGV")
+rubygems_path = Pathname.new(__FILE__).join("../../tmp/rubygems").expand_path
+unless rubygems_path.directory?
+  rubygems_path.parent.mkpath unless rubygems_path.directory?
+  run("git", "clone", "https://github.com/rubygems/rubygems.git", rubygems_path.to_s)
+end
+Dir.chdir(rubygems_path) do
+  version = "v#{version}" if version =~ /\A\d/
+  run("git", "checkout", version, "--quiet")
+end if version
+
+rubygems_lib = rubygems_path + "lib"
+ENV["RUBYOPT"] = %(-I#{rubygems_lib} #{ENV["RUBYOPT"]})
+
+if $0 != __FILE__
+  ARGV.unshift($0)
+elsif cmd = ARGV.first
+  possible_dirs = [
+    Pathname.new(__FILE__) + "..",
+    Pathname.new(__FILE__) + "../../exe",
+    rubygems_path + "bin",
+  ]
+  cmd = possible_dirs.map do |dir|
+    dir.join(cmd).expand_path
+  end.find(&:file?)
+  ARGV[0] = cmd.to_s if cmd
+end
+
+exec(*ARGV)