1 files changed, 146 insertions, 0 deletions
diff --git a/lib/bundler/inline.rb b/lib/bundler/inline.rb
new file mode 100644
index 0000000000..a1b8e0475e
--- /dev/null
+++ b/lib/bundler/inline.rb
@@ -0,0 +1,146 @@
+# frozen_string_literal: true
+
+# Allows for declaring a Gemfile inline in a ruby script, installing any gems
+# that aren't already installed on the user's system.
+#
+# @note Every gem that is specified in this 'Gemfile' will be `require`d, as if
+#       the user had manually called `Bundler.require`. To avoid a requested gem
+#       being automatically required, add the `:require => false` option to the
+#       `gem` dependency declaration.
+#
+# @param force_latest_compatible [Boolean] Force installing the *latest*
+#                                          compatible versions of the gems,
+#                                          even if compatible versions are
+#                                          already installed locally.
+#                                          This also logs output if the
+#                                          `:quiet` option is not set.
+#                                          Defaults to `false`.
+#
+# @param gemfile [Proc]    a block that is evaluated as a `Gemfile`.
+#
+# @example Using an inline Gemfile
+#
+#          #!/usr/bin/env ruby
+#
+#          require 'bundler/inline'
+#
+#          gemfile do
+#            source 'https://rubygems.org'
+#            gem 'json', require: false
+#            gem 'nap', require: 'rest'
+#            gem 'cocoapods', '~> 0.34.1'
+#          end
+#
+#          puts Pod::VERSION # => "0.34.4"
+#
+def gemfile(force_latest_compatible = false, options = {}, &gemfile)
+  require_relative "../bundler"
+  Bundler.reset!
+
+  opts = options.dup
+  ui = opts.delete(:ui) { Bundler::UI::Shell.new }
+  ui.level = "silent" if opts.delete(:quiet) || !force_latest_compatible
+  Bundler.ui = ui
+  raise ArgumentError, "Unknown options: #{opts.keys.join(", ")}" unless opts.empty?
+
+  old_gemfile = ENV["BUNDLE_GEMFILE"]
+  old_lockfile = ENV["BUNDLE_LOCKFILE"]
+
+  Bundler.unbundle_env!
+
+  begin
+    Bundler.instance_variable_set(:@bundle_path, Pathname.new(Gem.dir))
+    Bundler::SharedHelpers.set_env "BUNDLE_GEMFILE", "Gemfile"
+    Bundler::SharedHelpers.set_env "BUNDLE_LOCKFILE", "Gemfile.lock"
+
+    Bundler::Plugin.gemfile_install(&gemfile) if Bundler.settings[:plugins]
+    builder = Bundler::Dsl.new
+    builder.instance_eval(&gemfile)
+
+    Bundler.settings.temporary(deployment: false, frozen: false) do
+      definition = builder.to_definition(nil, true)
+      definition.validate_runtime!
+
+      if force_latest_compatible || definition.missing_specs?
+        do_install = -> do
+          Bundler.settings.temporary(inline: true, no_install: false) do
+            installer = Bundler::Installer.install(Bundler.root, definition, system: true)
+            installer.post_install_messages.each do |name, message|
+              Bundler.ui.info "Post-install message from #{name}:\n#{message}"
+            end
+          end
+        end
+
+        # When possible we do the install in a subprocess because to install
+        # gems we need to require some default gems like `securerandom` etc
+        # which may later conflict with the Gemfile requirements.
+        installed_in_fork = false
+        if Process.respond_to?(:fork)
+          Gem.load_yaml # Avoid NameError on Ruby 3.2's safe_yaml.rb after Gem::Specification.reset
+          _, status = Process.waitpid2(Process.fork do
+                                         $VERBOSE = nil
+                                         do_install.call end)
+          exit(status.exitstatus || status.to_i) unless status.success?
+
+          installed_in_fork = true
+
+          Bundler.reset!
+          Gem::Specification.reset
+          Bundler.instance_variable_set(:@bundle_path, Pathname.new(Gem.dir))
+
+          builder = Bundler::Dsl.new
+          builder.instance_eval(&gemfile)
+          builder.check_primary_source_safety
+
+          definition = builder.to_definition(nil, true)
+          definition.validate_runtime!
+        else
+          do_install.call
+        end
+      end
+
+      configure_forked_definition = ->(d) do
+        d.sources.rubygems_sources.each(&:remote!)
+        d.sources.git_sources.each do |source|
+          source.cached!
+          source.instance_variable_set(:@copied, true)
+        end
+        def d.lock(*); end
+      end
+      configure_forked_definition.call(definition) if installed_in_fork
+
+      begin
+        runtime = Bundler::Runtime.new(nil, definition).setup
+      rescue Gem::LoadError => e
+        name = e.name
+        version = e.requirement.requirements.first[1]
+        activated_version = Gem.loaded_specs[name].version
+
+        Bundler.ui.info \
+          "The #{name} gem was resolved to #{version}, but #{activated_version} was activated by Bundler while installing it, causing a conflict. " \
+          "Bundler will now retry resolving with #{activated_version} instead."
+
+        builder.dependencies.delete_if {|d| d.name == name }
+        builder.instance_eval { gem name, activated_version }
+        definition = builder.to_definition(nil, true)
+        configure_forked_definition.call(definition) if installed_in_fork
+
+        retry
+      end
+
+      runtime.require
+    end
+  ensure
+    if old_gemfile
+      ENV["BUNDLE_GEMFILE"] = old_gemfile
+    else
+      ENV["BUNDLE_GEMFILE"] = ""
+    end
+
+    if old_lockfile
+      ENV["BUNDLE_LOCKFILE"] = old_lockfile
+    else
+      ENV["BUNDLE_LOCKFILE"] = ""
+    end
+  end
+end