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, 175 insertions, 0 deletions

diff --git a/lib/bundler/gem_version_promoter.rb b/lib/bundler/gem_version_promoter.rb
new file mode 100644
index 0000000000..d60d823d9c
--- /dev/null
+++ b/lib/bundler/gem_version_promoter.rb
@@ -0,0 +1,175 @@
+# frozen_string_literal: true
+module Bundler
+  # This class contains all of the logic for determining the next version of a
+  # Gem to update to based on the requested level (patch, minor, major).
+  # Primarily designed to work with Resolver which will provide it the list of
+  # available dependency versions as found in its index, before returning it to
+  # to the resolution engine to select the best version.
+  class GemVersionPromoter
+    attr_reader :level, :locked_specs, :unlock_gems
+
+    # By default, strict is false, meaning every available version of a gem
+    # is returned from sort_versions. The order gives preference to the
+    # requested level (:patch, :minor, :major) but in complicated requirement
+    # cases some gems will by necessity by promoted past the requested level,
+    # or even reverted to older versions.
+    #
+    # If strict is set to true, the results from sort_versions will be
+    # truncated, eliminating any version outside the current level scope.
+    # This can lead to unexpected outcomes or even VersionConflict exceptions
+    # that report a version of a gem not existing for versions that indeed do
+    # existing in the referenced source.
+    attr_accessor :strict
+
+    # Given a list of locked_specs and a list of gems to unlock creates a
+    # GemVersionPromoter instance.
+    #
+    # @param locked_specs [SpecSet] All current locked specs. Unlike Definition
+    #   where this list is empty if all gems are being updated, this should
+    #   always be populated for all gems so this class can properly function.
+    # @param unlock_gems [String] List of gem names being unlocked. If empty,
+    #   all gems will be considered unlocked.
+    # @return [GemVersionPromoter]
+    def initialize(locked_specs = SpecSet.new([]), unlock_gems = [])
+      @level = :major
+      @strict = false
+      @locked_specs = locked_specs
+      @unlock_gems = unlock_gems
+      @sort_versions = {}
+    end
+
+    # @param value [Symbol] One of three Symbols: :major, :minor or :patch.
+    def level=(value)
+      v = case value
+          when String, Symbol
+            value.to_sym
+      end
+
+      raise ArgumentError, "Unexpected level #{v}. Must be :major, :minor or :patch" unless [:major, :minor, :patch].include?(v)
+      @level = v
+    end
+
+    # Given a Dependency and an Array of SpecGroups of available versions for a
+    # gem, this method will return the Array of SpecGroups sorted (and possibly
+    # truncated if strict is true) in an order to give preference to the current
+    # level (:major, :minor or :patch) when resolution is deciding what versions
+    # best resolve all dependencies in the bundle.
+    # @param dep [Dependency] The Dependency of the gem.
+    # @param spec_groups [SpecGroup] An array of SpecGroups for the same gem
+    #    named in the @dep param.
+    # @return [SpecGroup] A new instance of the SpecGroup Array sorted and
+    #    possibly filtered.
+    def sort_versions(dep, spec_groups)
+      before_result = "before sort_versions: #{debug_format_result(dep, spec_groups).inspect}" if ENV["DEBUG_RESOLVER"]
+
+      @sort_versions[dep] ||= begin
+        gem_name = dep.name
+
+        # An Array per version returned, different entries for different platforms.
+        # We only need the version here so it's ok to hard code this to the first instance.
+        locked_spec = locked_specs[gem_name].first
+
+        if strict
+          filter_dep_specs(spec_groups, locked_spec)
+        else
+          sort_dep_specs(spec_groups, locked_spec)
+        end.tap do |specs|
+          if ENV["DEBUG_RESOLVER"]
+            STDERR.puts before_result
+            STDERR.puts " after sort_versions: #{debug_format_result(dep, specs).inspect}"
+          end
+        end
+      end
+    end
+
+    # @return [bool] Convenience method for testing value of level variable.
+    def major?
+      level == :major
+    end
+
+    # @return [bool] Convenience method for testing value of level variable.
+    def minor?
+      level == :minor
+    end
+
+  private
+
+    def filter_dep_specs(spec_groups, locked_spec)
+      res = spec_groups.select do |spec_group|
+        if locked_spec && !major?
+          gsv = spec_group.version
+          lsv = locked_spec.version
+
+          must_match = minor? ? [0] : [0, 1]
+
+          matches = must_match.map {|idx| gsv.segments[idx] == lsv.segments[idx] }
+          (matches.uniq == [true]) ? (gsv >= lsv) : false
+        else
+          true
+        end
+      end
+
+      sort_dep_specs(res, locked_spec)
+    end
+
+    def sort_dep_specs(spec_groups, locked_spec)
+      return spec_groups unless locked_spec
+      @gem_name = locked_spec.name
+      @locked_version = locked_spec.version
+
+      result = spec_groups.sort do |a, b|
+        @a_ver = a.version
+        @b_ver = b.version
+        if major?
+          @a_ver <=> @b_ver
+        elsif either_version_older_than_locked
+          @a_ver <=> @b_ver
+        elsif segments_do_not_match(:major)
+          @b_ver <=> @a_ver
+        elsif !minor? && segments_do_not_match(:minor)
+          @b_ver <=> @a_ver
+        else
+          @a_ver <=> @b_ver
+        end
+      end
+      post_sort(result)
+    end
+
+    def either_version_older_than_locked
+      @a_ver < @locked_version || @b_ver < @locked_version
+    end
+
+    def segments_do_not_match(level)
+      index = [:major, :minor].index(level)
+      @a_ver.segments[index] != @b_ver.segments[index]
+    end
+
+    def unlocking_gem?
+      unlock_gems.empty? || unlock_gems.include?(@gem_name)
+    end
+
+    # Specific version moves can't always reliably be done during sorting
+    # as not all elements are compared against each other.
+    def post_sort(result)
+      # default :major behavior in Bundler does not do this
+      return result if major?
+      if unlocking_gem?
+        result
+      else
+        move_version_to_end(result, @locked_version)
+      end
+    end
+
+    def move_version_to_end(result, version)
+      move, keep = result.partition {|s| s.version.to_s == version.to_s }
+      keep.concat(move)
+    end
+
+    def debug_format_result(dep, spec_groups)
+      a = [dep.to_s,
+           spec_groups.map {|sg| [sg.version, sg.dependencies_for_activated_platforms.map {|dp| [dp.name, dp.requirement.to_s] }] }]
+      last_map = a.last.map {|sg_data| [sg_data.first.version, sg_data.last.map {|aa| aa.join(" ") }] }
+      [a.first, last_map, level, strict ? :strict : :not_strict]
+    end
+  end
+end