From 9ddff8d3582e0200b7594c3de24e7ad50604cd65 Mon Sep 17 00:00:00 2001
From: Jared Beck <jared@jaredbeck.com>
Date: Tue, 13 Dec 2016 22:41:09 -0500
Subject: [PATCH] Extract private method load_versions_for_hmt_association

---
 .rubocop_todo.yml          |  2 +-
 lib/paper_trail/reifier.rb | 38 +++++++++++++++++++++++---------------
 2 files changed, 24 insertions(+), 16 deletions(-)

diff --git a/.rubocop_todo.yml b/.rubocop_todo.yml
index 5b3e565e..cadc7cd3 100644
--- a/.rubocop_todo.yml
+++ b/.rubocop_todo.yml
@@ -2,7 +2,7 @@
 # one by one as the offenses are removed from the code base.
 
 Metrics/AbcSize:
-  Max: 24 # Goal: 15
+  Max: 22 # Goal: 15
 
 Metrics/CyclomaticComplexity:
   Max: 8 # Goal: 6
diff --git a/lib/paper_trail/reifier.rb b/lib/paper_trail/reifier.rb
index 53dc1b23..09ca5795 100644
--- a/lib/paper_trail/reifier.rb
+++ b/lib/paper_trail/reifier.rb
@@ -117,23 +117,12 @@ module PaperTrail
       end
 
       # @api private
-      def hmt_collection_through_belongs_to(through_collection, assoc, options, transaction_id)
-        collection_keys = through_collection.map { |through_model|
+      def hmt_collection_through_belongs_to(through_collection, assoc, options, tx_id)
+        ids = through_collection.map { |through_model|
           through_model.send(assoc.source_reflection.foreign_key)
         }
-        version_id_subquery = assoc.klass.paper_trail.version_class.
-          select("MIN(id)").
-          where("item_type = ?", assoc.class_name).
-          where("item_id IN (?)", collection_keys).
-          where(
-            "created_at >= ? OR transaction_id = ?",
-            options[:version_at],
-            transaction_id
-          ).
-          group("item_id").
-          to_sql
-        versions = versions_by_id(assoc.klass, version_id_subquery)
-        collection = Array.new assoc.klass.where(assoc.klass.primary_key => collection_keys)
+        versions = load_versions_for_hmt_association(assoc, ids, tx_id, options[:version_at])
+        collection = Array.new assoc.klass.where(assoc.klass.primary_key => ids)
         prepare_array_for_has_many(collection, options, versions)
         collection
       end
@@ -217,6 +206,25 @@ module PaperTrail
         versions_by_id(model.class, version_id_subquery)
       end
 
+      # Given a `has_many(through:)` association and an array of `ids`, return
+      # the version records from the point in time identified by `tx_id` or
+      # `version_at`.
+      # @api private
+      def load_versions_for_hmt_association(assoc, ids, tx_id, version_at)
+        version_id_subquery = assoc.klass.paper_trail.version_class.
+          select("MIN(id)").
+          where("item_type = ?", assoc.class_name).
+          where("item_id IN (?)", ids).
+          where(
+            "created_at >= ? OR transaction_id = ?",
+            version_at,
+            tx_id
+          ).
+          group("item_id").
+          to_sql
+        versions_by_id(assoc.klass, version_id_subquery)
+      end
+
       # Set all the attributes in this version on the model.
       def reify_attributes(model, version, attrs)
         enums = model.class.respond_to?(:defined_enums) ? model.class.defined_enums : {}