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, 45 insertions, 0 deletions

diff --git a/lib/bundler/vendor/molinillo/lib/molinillo/resolver.rb b/lib/bundler/vendor/molinillo/lib/molinillo/resolver.rb
new file mode 100644
index 0000000000..50d853b146
--- /dev/null
+++ b/lib/bundler/vendor/molinillo/lib/molinillo/resolver.rb
@@ -0,0 +1,45 @@
+# frozen_string_literal: true
+require 'bundler/vendor/molinillo/lib/molinillo/dependency_graph'
+
+module Bundler::Molinillo
+  # This class encapsulates a dependency resolver.
+  # The resolver is responsible for determining which set of dependencies to
+  # activate, with feedback from the {#specification_provider}
+  #
+  #
+  class Resolver
+    require 'bundler/vendor/molinillo/lib/molinillo/resolution'
+
+    # @return [SpecificationProvider] the specification provider used
+    #   in the resolution process
+    attr_reader :specification_provider
+
+    # @return [UI] the UI module used to communicate back to the user
+    #   during the resolution process
+    attr_reader :resolver_ui
+
+    # Initializes a new resolver.
+    # @param  [SpecificationProvider] specification_provider
+    #   see {#specification_provider}
+    # @param  [UI] resolver_ui
+    #   see {#resolver_ui}
+    def initialize(specification_provider, resolver_ui)
+      @specification_provider = specification_provider
+      @resolver_ui = resolver_ui
+    end
+
+    # Resolves the requested dependencies into a {DependencyGraph},
+    # locking to the base dependency graph (if specified)
+    # @param [Array] requested an array of 'requested' dependencies that the
+    #   {#specification_provider} can understand
+    # @param [DependencyGraph,nil] base the base dependency graph to which
+    #   dependencies should be 'locked'
+    def resolve(requested, base = DependencyGraph.new)
+      Resolution.new(specification_provider,
+                     resolver_ui,
+                     requested,
+                     base).
+        resolve
+    end
+  end
+end