Merge bundler to standard libraries.

  rubygems 2.7.x depends bundler-1.15.x. This is preparation for
  rubygems and bundler migration.

  * lib/bundler.rb, lib/bundler/*: files of bundler-1.15.4
  * spec/bundler/*: rspec examples of bundler-1.15.4. I applied patches.
    * https://github.com/bundler/bundler/pull/6007
    * Exclude not working examples on ruby repository.
    * Fake ruby interpriter instead of installed ruby.
  * Makefile.in: Added test task named `test-bundler`. This task is only
    working macOS/linux yet. I'm going to support Windows environment later.
  * tool/sync_default_gems.rb: Added sync task for bundler.

  [Feature #12733][ruby-core:77172]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@59779 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 81 insertions, 0 deletions

diff --git a/lib/bundler/plugin/api.rb b/lib/bundler/plugin/api.rb
new file mode 100644
index 0000000000..a2d5cbb4ac
--- /dev/null
+++ b/lib/bundler/plugin/api.rb
@@ -0,0 +1,81 @@
+# frozen_string_literal: true
+
+module Bundler
+  # This is the interfacing class represents the API that we intend to provide
+  # the plugins to use.
+  #
+  # For plugins to be independent of the Bundler internals they shall limit their
+  # interactions to methods of this class only. This will save them from breaking
+  # when some internal change.
+  #
+  # Currently we are delegating the methods defined in Bundler class to
+  # itself. So, this class acts as a buffer.
+  #
+  # If there is some change in the Bundler class that is incompatible to its
+  # previous behavior or if otherwise desired, we can reimplement(or implement)
+  # the method to preserve compatibility.
+  #
+  # To use this, either the class can inherit this class or use it directly.
+  # For example of both types of use, refer the file `spec/plugins/command.rb`
+  #
+  # To use it without inheriting, you will have to create an object of this
+  # to use the functions (except for declaration functions like command, source,
+  # and hooks).
+  module Plugin
+    class API
+      autoload :Source, "bundler/plugin/api/source"
+
+      # The plugins should declare that they handle a command through this helper.
+      #
+      # @param [String] command being handled by them
+      # @param [Class] (optional) class that handles the command. If not
+      #                 provided, the `self` class will be used.
+      def self.command(command, cls = self)
+        Plugin.add_command command, cls
+      end
+
+      # The plugins should declare that they provide a installation source
+      # through this helper.
+      #
+      # @param [String] the source type they provide
+      # @param [Class] (optional) class that handles the source. If not
+      #                 provided, the `self` class will be used.
+      def self.source(source, cls = self)
+        cls.send :include, Bundler::Plugin::API::Source
+        Plugin.add_source source, cls
+      end
+
+      def self.hook(event, &block)
+        Plugin.add_hook(event, &block)
+      end
+
+      # The cache dir to be used by the plugins for storage
+      #
+      # @return [Pathname] path of the cache dir
+      def cache_dir
+        Plugin.cache.join("plugins")
+      end
+
+      # A tmp dir to be used by plugins
+      # Accepts names that get concatenated as suffix
+      #
+      # @return [Pathname] object for the new directory created
+      def tmp(*names)
+        Bundler.tmp(["plugin", *names].join("-"))
+      end
+
+      def method_missing(name, *args, &blk)
+        return Bundler.send(name, *args, &blk) if Bundler.respond_to?(name)
+
+        return SharedHelpers.send(name, *args, &blk) if SharedHelpers.respond_to?(name)
+
+        super
+      end
+
+      def respond_to_missing?(name, include_private = false)
+        SharedHelpers.respond_to?(name, include_private) ||
+          Bundler.respond_to?(name, include_private) || super
+      end
+    end
+  end
+end