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, 65 insertions, 0 deletions

diff --git a/lib/bundler/retry.rb b/lib/bundler/retry.rb
new file mode 100644
index 0000000000..092fb866b3
--- /dev/null
+++ b/lib/bundler/retry.rb
@@ -0,0 +1,65 @@
+# frozen_string_literal: true
+module Bundler
+  # General purpose class for retrying code that may fail
+  class Retry
+    attr_accessor :name, :total_runs, :current_run
+
+    class << self
+      def default_attempts
+        default_retries + 1
+      end
+      alias_method :attempts, :default_attempts
+
+      def default_retries
+        Bundler.settings[:retry]
+      end
+    end
+
+    def initialize(name, exceptions = nil, retries = self.class.default_retries)
+      @name = name
+      @retries = retries
+      @exceptions = Array(exceptions) || []
+      @total_runs = @retries + 1 # will run once, then upto attempts.times
+    end
+
+    def attempt(&block)
+      @current_run = 0
+      @failed      = false
+      @error       = nil
+      run(&block) while keep_trying?
+      @result
+    end
+    alias_method :attempts, :attempt
+
+  private
+
+    def run(&block)
+      @failed      = false
+      @current_run += 1
+      @result = block.call
+    rescue => e
+      fail_attempt(e)
+    end
+
+    def fail_attempt(e)
+      @failed = true
+      if last_attempt? || @exceptions.any? {|k| e.is_a?(k) }
+        Bundler.ui.info "" unless Bundler.ui.debug?
+        raise e
+      end
+      return true unless name
+      Bundler.ui.info "" unless Bundler.ui.debug? # Add new line incase dots preceded this
+      Bundler.ui.warn "Retrying #{name} due to error (#{current_run.next}/#{total_runs}): #{e.class} #{e.message}", Bundler.ui.debug?
+    end
+
+    def keep_trying?
+      return true  if current_run.zero?
+      return false if last_attempt?
+      return true  if @failed
+    end
+
+    def last_attempt?
+      current_run >= total_runs
+    end
+  end
+end