Adds script to compute topological sort of Active Record models

script/topological_sort_models.rb

@@ -0,0 +1,36 @@
+require 'tsort'
+require 'set'
+
+class Graph < Hash
+  include TSort
+
+  alias tsort_each_node each_key
+
+  def tsort_each_child(node, &block)
+    fetch(node).each(&block)
+  end
+end
+
+def children(model)
+  Set.new.tap do |children|
+    model.reflect_on_all_associations.each do |association|
+      next unless [:has_many, :has_one].include?(association.macro)
+      next if association.options[:through]
+
+      children << association.klass
+    end
+  end
+end
+
+Dir.glob('app/models/**/*.rb') do |model|
+  load model
+end
+
+graph = Graph.new
+ActiveRecord::Base.descendants.each do |model|
+  graph[model] = children(model) unless model.abstract_class?
+end
+
+graph.tsort.reverse_each do |klass|
+  puts klass.name
+end