Fix 'dangerous errors' when using in Rails 5.2

.travis.yml

@@ -9,12 +9,15 @@ gemfile:
   - gemfiles/mysql_ar_42.gemfile
   - gemfiles/mysql2_ar_50.gemfile
   - gemfiles/mysql2_ar_51.gemfile
+  - gemfiles/mysql2_ar_52.gemfile
   - gemfiles/pg_ar_42.gemfile
   - gemfiles/pg_ar_50.gemfile
   - gemfiles/pg_ar_51.gemfile
+  - gemfiles/pg_ar_52.gemfile
   - gemfiles/sqlite3_ar_42.gemfile
   - gemfiles/sqlite3_ar_50.gemfile
   - gemfiles/sqlite3_ar_51.gemfile
+  - gemfiles/sqlite3_ar_52.gemfile
 
 matrix:
   include:

Appraisals

@@ -1,5 +1,5 @@
 %w(mysql pg sqlite3).each do |db_type|
-  %w(3.2.22.5 4.2.10 5.0.7 5.1.6).each do |ar_version|
+  %w(3.2.22.5 4.2.10 5.0.7 5.1.6 5.2.0).each do |ar_version|
     # rails 5.0 only supports 'mysql2' driver
     # rails 4.2 supports both
     db_gem = db_type

gemfiles/mysql2_ar_52.gemfile

@@ -0,0 +1,17 @@
+# This file was generated by Appraisal
+
+source "https://rubygems.org"
+
+gem "appraisal"
+gem "coveralls", require: false
+gem "activerecord", "5.2.0"
+if RUBY_VERSION < "2.0"
+  gem "json", "~> 1.8.3"
+else
+  gem "json"
+end
+gem "term-ansicolor", "~> 1.3.2"
+gem "tins", "~> 1.6.0"
+gem "mysql2"
+
+gemspec path: "../"

gemfiles/pg_ar_52.gemfile

@@ -0,0 +1,17 @@
+# This file was generated by Appraisal
+
+source "https://rubygems.org"
+
+gem "appraisal"
+gem "coveralls", require: false
+gem "activerecord", "5.2.0"
+if RUBY_VERSION < "2.0"
+  gem "json", "~> 1.8.3"
+else
+  gem "json"
+end
+gem "term-ansicolor", "~> 1.3.2"
+gem "tins", "~> 1.6.0"
+gem "pg", "0.18.4"
+
+gemspec path: "../"

gemfiles/sqlite3_ar_52.gemfile

@@ -0,0 +1,16 @@
+# This file was generated by Appraisal
+
+source "https://rubygems.org"
+
+gem "appraisal"
+gem "coveralls", require: false
+gem "activerecord", "5.2.0"
+if RUBY_VERSION < "2.0"
+  gem "json", "~> 1.8.3"
+else
+  gem "json"
+end
+gem "term-ansicolor", "~> 1.3.2"
+gem "tins", "~> 1.6.0"
+
+gemspec path: "../"

lib/ancestry/has_ancestry.rb

@@ -46,9 +46,9 @@ def has_ancestry options = {}
       scope :siblings_of, lambda { |object| where(sibling_conditions(object)) }
       scope :ordered_by_ancestry, Proc.new { |order|
         if %w(mysql mysql2 sqlite sqlite3 postgresql).include?(connection.adapter_name.downcase) && ActiveRecord::VERSION::MAJOR >= 5
-          reorder("coalesce(#{connection.quote_table_name(table_name)}.#{connection.quote_column_name(ancestry_column)}, '')", order)
+          reorder(Arel.sql("coalesce(#{connection.quote_table_name(table_name)}.#{connection.quote_column_name(ancestry_column)}, '')"), order)
         else
-          reorder("(CASE WHEN #{connection.quote_table_name(table_name)}.#{connection.quote_column_name(ancestry_column)} IS NULL THEN 0 ELSE 1 END), #{connection.quote_table_name(table_name)}.#{connection.quote_column_name(ancestry_column)}", order)
+          reorder(Arel.sql("(CASE WHEN #{connection.quote_table_name(table_name)}.#{connection.quote_column_name(ancestry_column)} IS NULL THEN 0 ELSE 1 END), #{connection.quote_table_name(table_name)}.#{connection.quote_column_name(ancestry_column)}"), order)
         end
       }
       scope :ordered_by_ancestry_and, Proc.new { |order| ordered_by_ancestry(order) }

lib/ancestry/instance_methods.rb

@@ -114,13 +114,7 @@ def ancestor_was_conditions
     end
 
     def ancestor_ids_was
-      relevant_attributes = if ActiveRecord::VERSION::STRING >= '5.1.0'
-        saved_changes.transform_values(&:first)
-      else
-        changed_attributes
-      end
-
-      parse_ancestry_column(relevant_attributes[self.ancestry_base_class.ancestry_column.to_s])
+      parse_ancestry_column(send("#{self.ancestry_base_class.ancestry_column}_was"))
     end
 
     def path_ids