1 files changed, 66 insertions, 0 deletions
diff --git a/lib/rubygems/vendor/molinillo/lib/molinillo/dependency_graph/add_edge_no_circular.rb b/lib/rubygems/vendor/molinillo/lib/molinillo/dependency_graph/add_edge_no_circular.rb
new file mode 100644
index 0000000000..aa9815c5ae
--- /dev/null
+++ b/lib/rubygems/vendor/molinillo/lib/molinillo/dependency_graph/add_edge_no_circular.rb
@@ -0,0 +1,66 @@
+# frozen_string_literal: true
+
+require_relative 'action'
+module Gem::Molinillo
+  class DependencyGraph
+    # @!visibility private
+    # (see DependencyGraph#add_edge_no_circular)
+    class AddEdgeNoCircular < Action
+      # @!group Action
+
+      # (see Action.action_name)
+      def self.action_name
+        :add_vertex
+      end
+
+      # (see Action#up)
+      def up(graph)
+        edge = make_edge(graph)
+        edge.origin.outgoing_edges << edge
+        edge.destination.incoming_edges << edge
+        edge
+      end
+
+      # (see Action#down)
+      def down(graph)
+        edge = make_edge(graph)
+        delete_first(edge.origin.outgoing_edges, edge)
+        delete_first(edge.destination.incoming_edges, edge)
+      end
+
+      # @!group AddEdgeNoCircular
+
+      # @return [String] the name of the origin of the edge
+      attr_reader :origin
+
+      # @return [String] the name of the destination of the edge
+      attr_reader :destination
+
+      # @return [Object] the requirement that the edge represents
+      attr_reader :requirement
+
+      # @param  [DependencyGraph] graph the graph to find vertices from
+      # @return [Edge] The edge this action adds
+      def make_edge(graph)
+        Edge.new(graph.vertex_named(origin), graph.vertex_named(destination), requirement)
+      end
+
+      # Initialize an action to add an edge to a dependency graph
+      # @param [String] origin the name of the origin of the edge
+      # @param [String] destination the name of the destination of the edge
+      # @param [Object] requirement the requirement that the edge represents
+      def initialize(origin, destination, requirement)
+        @origin = origin
+        @destination = destination
+        @requirement = requirement
+      end
+
+      private
+
+      def delete_first(array, item)
+        return unless index = array.index(item)
+        array.delete_at(index)
+      end
+    end
+  end
+end