diff --git a/.github/CONTRIBUTING.md b/.github/CONTRIBUTING.md
index 4b169cda..902038fb 100644
--- a/.github/CONTRIBUTING.md
+++ b/.github/CONTRIBUTING.md
@@ -48,6 +48,10 @@ cd ../..
 
 # Run tests
 DB=sqlite bundle exec appraisal ar-4.2 rake
+
+# Run a single test file
+DB=sqlite bundle exec appraisal ar-4.2 ruby -I test test/unit/associations_test.rb
+DB=sqlite bundle exec appraisal ar-4.2 rspec spec/paper_trail/serializers/json_spec.rb
 ```
 
 ### Test sqlite, AR 5
diff --git a/.rubocop.yml b/.rubocop.yml
index a872758a..9e1f51b7 100644
--- a/.rubocop.yml
+++ b/.rubocop.yml
@@ -15,7 +15,7 @@ AllCops:
     - test/dummy/db/schema.rb # Generated, out of our control
 
   # Set to lowest supported version
-  TargetRubyVersion: 1.9
+  TargetRubyVersion: 2.1
 
 # Migrations often contain long up/down methods, and extracting smaller methods
 # from these is of questionable value.
@@ -23,6 +23,10 @@ Metrics/AbcSize:
   Exclude:
     - 'test/dummy/db/migrate/*'
 
+# Not a useful metric compared to, e.g. `AbcSize`.
+Metrics/BlockLength:
+  Enabled: false
+
 # Not a useful metric compared to, e.g. `AbcSize`.
 Metrics/ClassLength:
   Enabled: false
@@ -43,6 +47,13 @@ Metrics/MethodLength:
 Metrics/ModuleLength:
   Enabled: false
 
+# In an ideal world, each example has a single expectation. In the real world,
+# sometimes setup is a pain and you don't want to duplicate setup in multiple
+# examples, or make the specs more confusing with many nested `context`s, and
+# the practical thing is to have multiple expectations.
+RSpec/MultipleExpectations:
+  Enabled: false
+
 Style/AlignParameters:
   EnforcedStyle: with_fixed_indentation
 
@@ -59,17 +70,25 @@ Style/DotPosition:
 Style/DoubleNegation:
   Enabled: false
 
+Style/FileName:
+  Exclude:
+    - Appraisals
+
 # The decision of when to use a guard clause to improve readability is subtle,
 # and it's not clear that it can be linted. Certainly, the default
 # `MinBodyLength` of 1 can actually hurt readability.
 Style/GuardClause:
-  MinBodyLength: 3
+  Enabled: false
 
 # Use postfix (modifier) conditionals for one-liners, unless doing so would
 # exceed 60 characters.
 Style/IfUnlessModifier:
   MaxLineLength: 60
 
+Style/IndentHeredoc:
+  Exclude:
+    - paper_trail.gemspec
+
 # The Ruby Style Guide says:
 #
 # > Use \ instead of + or << to concatenate two string literals at line end.
diff --git a/.rubocop_todo.yml b/.rubocop_todo.yml
index d3e8dfc9..fb310989 100644
--- a/.rubocop_todo.yml
+++ b/.rubocop_todo.yml
@@ -3,6 +3,9 @@ require: rubocop-rspec
 # Remove these configuration records
 # one by one as the offenses are removed from the code base.
 
+Lint/AmbiguousBlockAssociation:
+  Enabled: false
+
 Metrics/AbcSize:
   Max: 22 # Goal: 15
 
@@ -15,20 +18,35 @@ Metrics/PerceivedComplexity:
 Style/FrozenStringLiteralComment:
   Enabled: false
 
-RSpec/InstanceVariable:
-  Enabled: false
-
-RSpec/ExampleWording:
+RSpec/BeforeAfterAll:
   Enabled: false
 
 RSpec/DescribedClass:
   Enabled: false
 
+RSpec/ExampleWording:
+  Enabled: false
+
 RSpec/ExampleLength:
   Enabled: false
 
+RSpec/ExpectActual:
+  Enabled: false
+
+RSpec/FilePath:
+  Enabled: false
+
+RSpec/MessageSpies:
+  Enabled: false
+
+RSpec/NamedSubject:
+  Enabled: false
+
+RSpec/NestedGroups:
+  Enabled: false
+
 RSpec/NotToNot:
   Enabled: false
 
-RSpec/FilePath:
+Security/YAMLLoad:
   Enabled: false
diff --git a/Appraisals b/Appraisals
index 12009e91..339dd857 100644
--- a/Appraisals
+++ b/Appraisals
@@ -18,7 +18,7 @@ end
 appraise "ar-5.0" do
   gem "activerecord", "~> 5.0.0"
   gem "rspec-rails", "~> 3.5.1"
-  gem 'rails-controller-testing'
+  gem "rails-controller-testing"
 end
 
 appraise "ar_master" do
diff --git a/Rakefile b/Rakefile
index 77e36939..e256dd34 100644
--- a/Rakefile
+++ b/Rakefile
@@ -27,4 +27,4 @@ require "rubocop/rake_task"
 RuboCop::RakeTask.new
 
 desc "Default: run all available test suites"
-task default: [:rubocop, :prepare, :test, :spec]
+task default: %i(rubocop prepare test spec)
diff --git a/doc/bug_report_template.rb b/doc/bug_report_template.rb
index cdcae1e1..2f17675a 100644
--- a/doc/bug_report_template.rb
+++ b/doc/bug_report_template.rb
@@ -34,7 +34,7 @@ ActiveRecord::Schema.define do
     t.integer :transaction_id
     t.datetime :created_at
   end
-  add_index :versions, [:item_type, :item_id]
+  add_index :versions, %i(item_type item_id)
   add_index :versions, [:transaction_id]
 
   create_table :version_associations do |t|
@@ -43,7 +43,7 @@ ActiveRecord::Schema.define do
     t.integer  :foreign_key_id
   end
   add_index :version_associations, [:version_id]
-  add_index :version_associations, [:foreign_key_name, :foreign_key_id],
+  add_index :version_associations, %i(foreign_key_name foreign_key_id),
     name: "index_version_associations_on_foreign_key"
 end
 ActiveRecord::Base.logger = Logger.new(STDOUT)
diff --git a/lib/generators/paper_trail/templates/create_version_associations.rb b/lib/generators/paper_trail/templates/create_version_associations.rb
index e15132c3..7009a5ae 100644
--- a/lib/generators/paper_trail/templates/create_version_associations.rb
+++ b/lib/generators/paper_trail/templates/create_version_associations.rb
@@ -9,7 +9,7 @@ class CreateVersionAssociations < ActiveRecord::Migration
     end
     add_index :version_associations, [:version_id]
     add_index :version_associations,
-      [:foreign_key_name, :foreign_key_id],
+      %i(foreign_key_name foreign_key_id),
       name: "index_version_associations_on_foreign_key"
   end
 
diff --git a/lib/generators/paper_trail/templates/create_versions.rb b/lib/generators/paper_trail/templates/create_versions.rb
index 47301d56..900cb1a7 100644
--- a/lib/generators/paper_trail/templates/create_versions.rb
+++ b/lib/generators/paper_trail/templates/create_versions.rb
@@ -38,7 +38,7 @@ class CreateVersions < ActiveRecord::Migration
       #
       t.datetime :created_at
     end
-    add_index :versions, [:item_type, :item_id]
+    add_index :versions, %i(item_type item_id)
   end
 
   private
diff --git a/lib/paper_trail/model_config.rb b/lib/paper_trail/model_config.rb
index d4ef0fb6..f626cb98 100644
--- a/lib/paper_trail/model_config.rb
+++ b/lib/paper_trail/model_config.rb
@@ -76,7 +76,7 @@ module PaperTrail
     # "class attributes", instance methods, and more.
     # @api private
     def setup(options = {})
-      options[:on] ||= [:create, :update, :destroy]
+      options[:on] ||= %i(create update destroy)
       options[:on] = Array(options[:on]) # Support single symbol
       @model_class.send :include, ::PaperTrail::Model::InstanceMethods
       if ::ActiveRecord::VERSION::STRING < "4.2"
@@ -167,7 +167,7 @@ module PaperTrail
       @model_class.class_attribute :paper_trail_options
       @model_class.paper_trail_options = options.dup
 
-      [:ignore, :skip, :only].each do |k|
+      %i(ignore skip only).each do |k|
         @model_class.paper_trail_options[k] = [@model_class.paper_trail_options[k]].
           flatten.
           compact.
diff --git a/lib/paper_trail/serializers/yaml.rb b/lib/paper_trail/serializers/yaml.rb
index e054e969..ee54e6cb 100644
--- a/lib/paper_trail/serializers/yaml.rb
+++ b/lib/paper_trail/serializers/yaml.rb
@@ -24,33 +24,10 @@ module PaperTrail
       # value in the serialized `object_changes`.
       def where_object_changes_condition(arel_field, field, value)
         # Need to check first (before) and secondary (after) fields
-        m1 = nil
-        m2 = nil
-        case yaml_engine_id
-        when :psych
-          m1 = "%\n#{field}:\n- #{value}\n%"
-          m2 = "%\n#{field}:\n-%\n- #{value}\n%"
-        when :syck
-          # Syck adds extra spaces into array dumps
-          m1 = "%\n#{field}: \n%- #{value}\n%"
-          m2 = "%\n#{field}: \n-%\n- #{value}\n%"
-        else
-          raise "Unknown yaml engine"
-        end
+        m1 = "%\n#{field}:\n- #{value}\n%"
+        m2 = "%\n#{field}:\n-%\n- #{value}\n%"
         arel_field.matches(m1).or(arel_field.matches(m2))
       end
-
-      # Returns a symbol identifying the YAML engine. Syck was removed from
-      # the ruby stdlib in ruby 2.0, but is still available as a gem.
-      # @api private
-      def yaml_engine_id
-        if (defined?(::YAML::ENGINE) && ::YAML::ENGINE.yamler == "psych") ||
-            (defined?(::Psych) && ::YAML == ::Psych)
-          :psych
-        else
-          :syck
-        end
-      end
     end
   end
 end
diff --git a/lib/paper_trail/version_concern.rb b/lib/paper_trail/version_concern.rb
index 7718eb37..5ab7326b 100644
--- a/lib/paper_trail/version_concern.rb
+++ b/lib/paper_trail/version_concern.rb
@@ -162,13 +162,13 @@ module PaperTrail
       # Returns whether the `object` column is using the `json` type supported
       # by PostgreSQL.
       def object_col_is_json?
-        [:json, :jsonb].include?(columns_hash["object"].type)
+        %i(json jsonb).include?(columns_hash["object"].type)
       end
 
       # Returns whether the `object_changes` column is using the `json` type
       # supported by PostgreSQL.
       def object_changes_col_is_json?
-        [:json, :jsonb].include?(columns_hash["object_changes"].try(:type))
+        %i(json jsonb).include?(columns_hash["object_changes"].try(:type))
       end
     end
 
@@ -306,8 +306,7 @@ module PaperTrail
       end
     end
 
-    # Checks that a value has been set for the `version_limit` config
-    # option, and if so enforces it.
+    # Enforces the `version_limit`, if set. Default: no limit.
     # @api private
     def enforce_version_limit!
       limit = PaperTrail.config.version_limit
diff --git a/paper_trail.gemspec b/paper_trail.gemspec
index 07219a68..b2c72d44 100644
--- a/paper_trail.gemspec
+++ b/paper_trail.gemspec
@@ -41,8 +41,8 @@ has been destroyed.
   s.add_development_dependency "generator_spec", "~> 0.9.3"
   s.add_development_dependency "database_cleaner", "~> 1.2"
   s.add_development_dependency "pry-nav", "~> 0.2.4"
-  s.add_development_dependency "rubocop", "~> 0.41.2"
-  s.add_development_dependency "rubocop-rspec", "~> 1.5.1"
+  s.add_development_dependency "rubocop", "~> 0.48.0"
+  s.add_development_dependency "rubocop-rspec", "~> 1.15.0"
   s.add_development_dependency "timecop", "~> 0.8.0"
   s.add_development_dependency "sqlite3", "~> 1.2"
   s.add_development_dependency "pg", "~> 0.19.0"
diff --git a/spec/models/boolit_spec.rb b/spec/models/boolit_spec.rb
index 543d48dd..c5d6fb93 100644
--- a/spec/models/boolit_spec.rb
+++ b/spec/models/boolit_spec.rb
@@ -10,6 +10,7 @@ describe Boolit, type: :model do
 
   describe "Versioning", versioning: true do
     subject { Boolit.create! }
+
     before { subject.update_attributes!(name: FFaker::Name.name) }
 
     it "should have versions" do
diff --git a/spec/models/callback_modifier_spec.rb b/spec/models/callback_modifier_spec.rb
index bb7134ad..9956ad7a 100644
--- a/spec/models/callback_modifier_spec.rb
+++ b/spec/models/callback_modifier_spec.rb
@@ -62,7 +62,7 @@ describe CallbackModifier, type: :model do
       context "when no callback-method used" do
         it "should set paper_trail_options[:on] to [:create, :update, :destroy]" do
           modifier = DefaultModifier.create!(some_content: FFaker::Lorem.sentence)
-          expect(modifier.paper_trail_options[:on]).to eq [:create, :update, :destroy]
+          expect(modifier.paper_trail_options[:on]).to eq %i(create update destroy)
         end
 
         it "should default to track destroy" do
diff --git a/spec/models/version_spec.rb b/spec/models/version_spec.rb
index 16784ad2..41b8d040 100644
--- a/spec/models/version_spec.rb
+++ b/spec/models/version_spec.rb
@@ -46,13 +46,15 @@ describe PaperTrail::Version, type: :model do
         end
 
         context "Has previous version", versioning: true do
+          subject { widget.versions.last }
+
           let(:name) { FFaker::Name.name }
           let(:widget) { Widget.create!(name: FFaker::Name.name) }
+
           before do
             widget.versions.first.update_attributes!(whodunnit: name)
             widget.update_attributes!(name: FFaker::Name.first_name)
           end
-          subject { widget.versions.last }
 
           specify { expect(subject.previous).to be_instance_of(PaperTrail::Version) }
 
@@ -79,9 +81,10 @@ describe PaperTrail::Version, type: :model do
       end
 
       describe "#terminator" do
-        let(:attributes) { { whodunnit: FFaker::Name.first_name } }
         subject { PaperTrail::Version.new attributes }
 
+        let(:attributes) { { whodunnit: FFaker::Name.first_name } }
+
         it { is_expected.to respond_to(:terminator) }
 
         it "is an alias for the `whodunnit` attribute" do
diff --git a/spec/models/widget_spec.rb b/spec/models/widget_spec.rb
index f2caf427..422fd0b7 100644
--- a/spec/models/widget_spec.rb
+++ b/spec/models/widget_spec.rb
@@ -51,7 +51,7 @@ describe Widget, type: :model do
   end
 
   describe "Callbacks", versioning: true do
-    describe :before_save do
+    describe "before_save" do
       context ":on => :update" do
         before { widget.update_attributes!(name: "Foobar") }
 
@@ -66,7 +66,7 @@ describe Widget, type: :model do
       end
     end
 
-    describe :after_create do
+    describe "after_create" do
       let(:widget) { Widget.create!(name: "Foobar", created_at: Time.now - 1.week) }
 
       it "corresponding version should use the widget's `updated_at`" do
@@ -74,7 +74,7 @@ describe Widget, type: :model do
       end
     end
 
-    describe :after_update do
+    describe "after_update" do
       before { widget.update_attributes!(name: "Foobar", updated_at: Time.now + 1.week) }
 
       subject { widget.versions.last.reify }
@@ -91,7 +91,7 @@ describe Widget, type: :model do
       end
     end
 
-    describe :after_destroy do
+    describe "after_destroy" do
       it "should create a version for that event" do
         expect { widget.destroy }.to change(widget.versions, :count).by(1)
       end
@@ -104,7 +104,7 @@ describe Widget, type: :model do
       end
     end
 
-    describe :after_rollback do
+    describe "after_rollback" do
       let(:rolled_back_name) { "Big Moo" }
 
       before do
@@ -194,7 +194,10 @@ describe Widget, type: :model do
         describe "return value" do
           let(:orig_name) { FFaker::Name.name }
           let(:new_name) { FFaker::Name.name }
-          before { PaperTrail.whodunnit = orig_name }
+
+          before do
+            PaperTrail.whodunnit = orig_name
+          end
 
           context "accessed from live model instance" do
             specify { expect(widget.paper_trail).to be_live }
diff --git a/spec/modules/version_concern_spec.rb b/spec/modules/version_concern_spec.rb
index 0611c071..10574084 100644
--- a/spec/modules/version_concern_spec.rb
+++ b/spec/modules/version_concern_spec.rb
@@ -18,14 +18,11 @@ describe PaperTrail::VersionConcern do
   end
 
   describe "persistence", versioning: true do
-    before do
-      @foo_doc = Foo::Document.create!(name: "foobar")
-      @bar_doc = Bar::Document.create!(name: "raboof")
-    end
-
     it "should store versions in the correct corresponding db location" do
-      expect(@foo_doc.versions.first).to be_instance_of(Foo::Version)
-      expect(@bar_doc.versions.first).to be_instance_of(Bar::Version)
+      foo_doc = Foo::Document.create!(name: "foobar")
+      bar_doc = Bar::Document.create!(name: "raboof")
+      expect(foo_doc.versions.first).to be_instance_of(Foo::Version)
+      expect(bar_doc.versions.first).to be_instance_of(Bar::Version)
     end
   end
 end
diff --git a/spec/modules/version_number_spec.rb b/spec/modules/version_number_spec.rb
index 85896bfe..632b2ba4 100644
--- a/spec/modules/version_number_spec.rb
+++ b/spec/modules/version_number_spec.rb
@@ -4,25 +4,25 @@ describe PaperTrail::VERSION do
   describe "Constants" do
     subject { PaperTrail::VERSION }
 
-    describe :MAJOR do
+    describe "MAJOR" do
       it { is_expected.to be_const_defined(:MAJOR) }
       it { expect(subject::MAJOR).to be_a(Integer) }
     end
-    describe :MINOR do
+    describe "MINOR" do
       it { is_expected.to be_const_defined(:MINOR) }
       it { expect(subject::MINOR).to be_a(Integer) }
     end
-    describe :TINY do
+    describe "TINY" do
       it { is_expected.to be_const_defined(:TINY) }
       it { expect(subject::TINY).to be_a(Integer) }
     end
-    describe :PRE do
+    describe "PRE" do
       it { is_expected.to be_const_defined(:PRE) }
       if PaperTrail::VERSION::PRE
         it { expect(subject::PRE).to be_instance_of(String) }
       end
     end
-    describe :STRING do
+    describe "STRING" do
       it { is_expected.to be_const_defined(:STRING) }
       it { expect(subject::STRING).to be_instance_of(String) }
 
diff --git a/spec/paper_trail/cleaner_spec.rb b/spec/paper_trail/cleaner_spec.rb
index e1048c84..747c052f 100644
--- a/spec/paper_trail/cleaner_spec.rb
+++ b/spec/paper_trail/cleaner_spec.rb
@@ -2,34 +2,36 @@ require "rails_helper"
 
 module PaperTrail
   RSpec.describe Cleaner, versioning: true do
-    def populate_db!
-      @animals = [@animal = Animal.new, @dog = Dog.new, @cat = Cat.new]
-      @animals.each do |animal|
-        3.times { animal.update_attribute(:name, FFaker::Name.name) }
-      end
-    end
-
     describe "clean_versions!" do
+      let(:animal) { ::Animal.new }
+      let(:dog) { ::Dog.new }
+      let(:cat) { ::Cat.new }
+      let(:animals) { [animal, dog, cat] }
+
       before do
-        populate_db!
+        animals.each do |animal|
+          3.times do
+            animal.update_attribute(:name, FFaker::Name.name)
+          end
+        end
       end
 
       it "baseline test setup" do
         expect(PaperTrail::Version.count).to(eq(9))
-        @animals.each { |animal| expect(animal.versions.size).to(eq(3)) }
+        animals.each { |animal| expect(animal.versions.size).to(eq(3)) }
       end
 
       context "no options provided" do
         it "removes extra versions for each item" do
           PaperTrail.clean_versions!
           expect(PaperTrail::Version.count).to(eq(3))
-          @animals.each { |animal| expect(animal.versions.size).to(eq(1)) }
+          animals.each { |animal| expect(animal.versions.size).to(eq(1)) }
         end
 
         it "removes the earliest version(s)" do
-          before = @animals.map { |animal| animal.versions.last.reify.name }
+          before = animals.map { |animal| animal.versions.last.reify.name }
           PaperTrail.clean_versions!
-          after = @animals.map { |animal| animal.versions.last.reify.name }
+          after = animals.map { |animal| animal.versions.last.reify.name }
           expect(after).to(eq(before))
         end
       end
@@ -38,44 +40,44 @@ module PaperTrail
         it "keeps two records, instead of the usual one" do
           PaperTrail.clean_versions!(keeping: 2)
           expect(PaperTrail::Version.all.count).to(eq(6))
-          @animals.each { |animal| expect(animal.versions.size).to(eq(2)) }
+          animals.each { |animal| expect(animal.versions.size).to(eq(2)) }
         end
       end
 
       context "with the :date option" do
         it "only deletes versions created on the given date" do
-          @animal.versions.each do |ver|
+          animal.versions.each do |ver|
             ver.update_attribute(:created_at, (ver.created_at - 1.day))
           end
-          @date = @animal.versions.first.created_at.to_date
-          @animal.update_attribute(:name, FFaker::Name.name)
+          date = animal.versions.first.created_at.to_date
+          animal.update_attribute(:name, FFaker::Name.name)
           expect(PaperTrail::Version.count).to(eq(10))
-          expect(@animal.versions.size).to(eq(4))
-          expect(@animal.paper_trail.versions_between(@date, (@date + 1.day)).size).to(eq(3))
-          PaperTrail.clean_versions!(date: @date)
+          expect(animal.versions.size).to(eq(4))
+          expect(animal.paper_trail.versions_between(date, (date + 1.day)).size).to(eq(3))
+          PaperTrail.clean_versions!(date: date)
           expect(PaperTrail::Version.count).to(eq(8))
-          expect(@animal.versions.reload.size).to(eq(2))
-          expect(@animal.versions.first.created_at.to_date).to(eq(@date))
+          expect(animal.versions.reload.size).to(eq(2))
+          expect(animal.versions.first.created_at.to_date).to(eq(date))
           # Why use `equal?` here instead of something less strict?
           # Doesn't `to_date` always produce a new date object?
-          expect(@date.equal?(@animal.versions.last.created_at.to_date)).to eq(false)
+          expect(date.equal?(animal.versions.last.created_at.to_date)).to eq(false)
         end
       end
 
       context "with the :item_id option" do
         context "single ID received" do
           it "only deletes the versions for the Item with that ID" do
-            PaperTrail.clean_versions!(item_id: @animal.id)
-            expect(@animal.versions.size).to(eq(1))
+            PaperTrail.clean_versions!(item_id: animal.id)
+            expect(animal.versions.size).to(eq(1))
             expect(PaperTrail::Version.count).to(eq(7))
           end
         end
 
         context "collection of IDs received" do
           it "only deletes versions for the Item(s) with those IDs" do
-            PaperTrail.clean_versions!(item_id: [@animal.id, @dog.id])
-            expect(@animal.versions.size).to(eq(1))
-            expect(@dog.versions.size).to(eq(1))
+            PaperTrail.clean_versions!(item_id: [animal.id, dog.id])
+            expect(animal.versions.size).to(eq(1))
+            expect(dog.versions.size).to(eq(1))
             expect(PaperTrail::Version.count).to(eq(5))
           end
         end
@@ -84,30 +86,31 @@ module PaperTrail
       context "options combinations" do
         context ":date" do
           before do
-            [@animal, @dog].each do |animal|
+            [animal, dog].each do |animal|
               animal.versions.each do |ver|
                 ver.update_attribute(:created_at, (ver.created_at - 1.day))
               end
               animal.update_attribute(:name, FFaker::Name.name)
             end
-            @date = @animal.versions.first.created_at.to_date
           end
 
           it "baseline test setup" do
+            date = animal.versions.first.created_at.to_date
             expect(PaperTrail::Version.count).to(eq(11))
-            [@animal, @dog].each do |animal|
+            [animal, dog].each do |animal|
               expect(animal.versions.size).to(eq(4))
-              expect(animal.versions.between(@date, (@date + 1.day)).size).to(eq(3))
+              expect(animal.versions.between(date, (date + 1.day)).size).to(eq(3))
             end
           end
 
           context "and :keeping" do
             it "restrict cleaning properly" do
-              PaperTrail.clean_versions!(date: @date, keeping: 2)
-              [@animal, @dog].each do |animal|
+              date = animal.versions.first.created_at.to_date
+              PaperTrail.clean_versions!(date: date, keeping: 2)
+              [animal, dog].each do |animal|
                 animal.versions.reload
                 expect(animal.versions.size).to(eq(3))
-                expect(animal.versions.between(@date, (@date + 1.day)).size).to(eq(2))
+                expect(animal.versions.between(date, (date + 1.day)).size).to(eq(2))
               end
               expect(PaperTrail::Version.count).to(eq(9))
             end
@@ -115,20 +118,22 @@ module PaperTrail
 
           context "and :item_id" do
             it "restrict cleaning properly" do
-              PaperTrail.clean_versions!(date: @date, item_id: @dog.id)
-              @dog.versions.reload
-              expect(@dog.versions.size).to(eq(2))
-              expect(@dog.versions.between(@date, (@date + 1.day)).size).to(eq(1))
+              date = animal.versions.first.created_at.to_date
+              PaperTrail.clean_versions!(date: date, item_id: dog.id)
+              dog.versions.reload
+              expect(dog.versions.size).to(eq(2))
+              expect(dog.versions.between(date, (date + 1.day)).size).to(eq(1))
               expect(PaperTrail::Version.count).to(eq(9))
             end
           end
 
           context ", :item_id, and :keeping" do
             it "restrict cleaning properly" do
-              PaperTrail.clean_versions!(date: @date, item_id: @dog.id, keeping: 2)
-              @dog.versions.reload
-              expect(@dog.versions.size).to(eq(3))
-              expect(@dog.versions.between(@date, (@date + 1.day)).size).to(eq(2))
+              date = animal.versions.first.created_at.to_date
+              PaperTrail.clean_versions!(date: date, item_id: dog.id, keeping: 2)
+              dog.versions.reload
+              expect(dog.versions.size).to(eq(3))
+              expect(dog.versions.between(date, (date + 1.day)).size).to(eq(2))
               expect(PaperTrail::Version.count).to(eq(10))
             end
           end
@@ -136,8 +141,8 @@ module PaperTrail
 
         context ":keeping and :item_id" do
           it "restrict cleaning properly" do
-            PaperTrail.clean_versions!(keeping: 2, item_id: @animal.id)
-            expect(@animal.versions.size).to(eq(2))
+            PaperTrail.clean_versions!(keeping: 2, item_id: animal.id)
+            expect(animal.versions.size).to(eq(2))
             expect(PaperTrail::Version.count).to(eq(8))
           end
         end
diff --git a/spec/paper_trail/serializers/custom_yaml_serializer_spec.rb b/spec/paper_trail/serializers/custom_yaml_serializer_spec.rb
index cd438a41..1a14318a 100644
--- a/spec/paper_trail/serializers/custom_yaml_serializer_spec.rb
+++ b/spec/paper_trail/serializers/custom_yaml_serializer_spec.rb
@@ -18,26 +18,27 @@ module CustomYamlSerializer
 end
 
 RSpec.describe CustomYamlSerializer do
-  before do
-    @hash = {}
-    (1..4).each { |i| @hash["key#{i}"] = [FFaker::Lorem.word, nil].sample }
-    @hash["tkey"] = nil
-    @hash[""] = "foo"
-    @hash_as_yaml = @hash.to_yaml
-  end
+  let(:word_hash) {
+    {
+      "key1" => ::FFaker::Lorem.word,
+      "key2" => nil,
+      "tkey" => nil,
+      "" => "foo"
+    }
+  }
 
   context(".load") do
     it("deserializes YAML to Ruby, removing pairs with blank keys or values") do
-      expect(CustomYamlSerializer.load(@hash_as_yaml)).to eq(
-        @hash.reject { |k, v| (k.blank? || v.blank?) }
+      expect(CustomYamlSerializer.load(word_hash.to_yaml)).to eq(
+        word_hash.reject { |k, v| (k.blank? || v.blank?) }
       )
     end
   end
 
   context(".dump") do
     it("serializes Ruby to YAML, removing pairs with nil values") do
-      expect(CustomYamlSerializer.dump(@hash)).to eq(
-        @hash.reject { |_k, v| v.nil? }.to_yaml
+      expect(CustomYamlSerializer.dump(word_hash)).to eq(
+        word_hash.reject { |_k, v| v.nil? }.to_yaml
       )
     end
   end
diff --git a/spec/paper_trail/serializers/json_spec.rb b/spec/paper_trail/serializers/json_spec.rb
index 29c5eec7..f1685d33 100644
--- a/spec/paper_trail/serializers/json_spec.rb
+++ b/spec/paper_trail/serializers/json_spec.rb
@@ -3,33 +3,29 @@ require "rails_helper"
 module PaperTrail
   module Serializers
     RSpec.describe JSON do
-      before do
-        @hash = {}
-        (1..4).each { |i| @hash["key#{i}"] = FFaker::Lorem.word }
-        @hash_as_json = @hash.to_json
-        @array = []
-        (rand(5) + 4).times { (@array << FFaker::Lorem.word) }
-        @array_as_json = @array.to_json
-      end
+      let(:word_hash) {
+        (1..4).each_with_object({}) { |i, a| a["key#{i}"] = ::FFaker::Lorem.word }
+      }
+      let(:word_array) { [].fill(0, rand(5) + 4) { ::FFaker::Lorem.word } }
 
       describe ".load" do
         it "deserialize JSON to Ruby" do
-          expect(PaperTrail::Serializers::JSON.load(@hash_as_json)).to(eq(@hash))
-          expect(PaperTrail::Serializers::JSON.load(@array_as_json)).to(eq(@array))
+          expect(described_class.load(word_hash.to_json)).to eq(word_hash)
+          expect(described_class.load(word_array.to_json)).to eq(word_array)
         end
       end
 
       describe ".dump" do
         it "serializes Ruby to JSON" do
-          expect(PaperTrail::Serializers::JSON.dump(@hash)).to(eq(@hash_as_json))
-          expect(PaperTrail::Serializers::JSON.dump(@array)).to(eq(@array_as_json))
+          expect(described_class.dump(word_hash)).to eq(word_hash.to_json)
+          expect(described_class.dump(word_array)).to eq(word_array.to_json)
         end
       end
 
       describe ".where_object_condition" do
         context "when value is a string" do
           it "construct correct WHERE query" do
-            matches = PaperTrail::Serializers::JSON.
+            matches = described_class.
               where_object_condition(PaperTrail::Version.arel_table[:object], :arg1, "Val 1")
             expect(matches.instance_of?(Arel::Nodes::Matches)).to(eq(true))
             expect("%\"arg1\":\"Val 1\"%").to(eq(matches.right.val))
@@ -38,7 +34,7 @@ module PaperTrail
 
         context "when value is null" do
           it "construct correct WHERE query" do
-            matches = PaperTrail::Serializers::JSON.
+            matches = described_class.
               where_object_condition(PaperTrail::Version.arel_table[:object], :arg1, nil)
             expect(matches.instance_of?(Arel::Nodes::Matches)).to(eq(true))
             expect("%\"arg1\":null%").to(eq(matches.right.val))
@@ -47,7 +43,7 @@ module PaperTrail
 
         context "when value is a number" do
           it "construct correct WHERE query" do
-            grouping = PaperTrail::Serializers::JSON.
+            grouping = described_class.
               where_object_condition(PaperTrail::Version.arel_table[:object], :arg1, -3.5)
             expect(grouping.instance_of?(Arel::Nodes::Grouping)).to(eq(true))
             matches = grouping.select { |v| v.instance_of?(Arel::Nodes::Matches) }
diff --git a/spec/paper_trail/version_limit_spec.rb b/spec/paper_trail/version_limit_spec.rb
index b0bce620..36ee46bc 100644
--- a/spec/paper_trail/version_limit_spec.rb
+++ b/spec/paper_trail/version_limit_spec.rb
@@ -2,11 +2,8 @@ require "rails_helper"
 
 module PaperTrail
   RSpec.describe Cleaner, versioning: true do
-    before do
-      @last_limit = PaperTrail.config.version_limit
-    end
     after do
-      PaperTrail.config.version_limit = @last_limit
+      PaperTrail.config.version_limit = nil
     end
 
     it "cleans up old versions" do
diff --git a/spec/paper_trail_spec.rb b/spec/paper_trail_spec.rb
index 5b4a6ce4..e5f0fb23 100644
--- a/spec/paper_trail_spec.rb
+++ b/spec/paper_trail_spec.rb
@@ -61,12 +61,12 @@ describe PaperTrail do
     end
   end
 
-  describe :version do
+  describe ".version" do
     it { expect(PaperTrail).to respond_to(:version) }
     it { expect(PaperTrail.version).to eq(PaperTrail::VERSION::STRING) }
   end
 
-  describe :whodunnit do
+  describe ".whodunnit" do
     before(:all) { PaperTrail.whodunnit = "foobar" }
 
     it "should get set to `nil` by default" do
@@ -74,7 +74,7 @@ describe PaperTrail do
     end
   end
 
-  describe :controller_info do
+  describe ".controller_info" do
     before(:all) { ::PaperTrail.controller_info = { foo: "bar" } }
 
     it "should get set to an empty hash before each test" do
diff --git a/test/dummy/app/models/custom_primary_key_record.rb b/test/dummy/app/models/custom_primary_key_record.rb
index 0c8e9ed1..8ed95736 100644
--- a/test/dummy/app/models/custom_primary_key_record.rb
+++ b/test/dummy/app/models/custom_primary_key_record.rb
@@ -1,11 +1,13 @@
 require "securerandom"
+
 class CustomPrimaryKeyRecord < ActiveRecord::Base
   self.primary_key = :uuid
 
   has_paper_trail class_name: "CustomPrimaryKeyRecordVersion"
-  # this unusual default_scope is to test the case of the Version#item association
+
+  # This default_scope is to test the case of the Version#item association
   # not returning the item due to unmatched default_scope on the model.
-  default_scope -> { where(name: "custom_primary_key_record") }
+  default_scope { where(name: "custom_primary_key_record") }
 
   before_create do
     self.uuid ||= SecureRandom.uuid
diff --git a/test/dummy/app/models/document.rb b/test/dummy/app/models/document.rb
index c79984ab..67056c23 100644
--- a/test/dummy/app/models/document.rb
+++ b/test/dummy/app/models/document.rb
@@ -1,6 +1,6 @@
 class Document < ActiveRecord::Base
   has_paper_trail(
     versions: :paper_trail_versions,
-    on: [:create, :update]
+    on: %i(create update)
   )
 end
diff --git a/test/dummy/app/models/not_on_update.rb b/test/dummy/app/models/not_on_update.rb
index c288084d..9f341b07 100644
--- a/test/dummy/app/models/not_on_update.rb
+++ b/test/dummy/app/models/not_on_update.rb
@@ -1,4 +1,4 @@
 # This model does not record versions when updated.
 class NotOnUpdate < ActiveRecord::Base
-  has_paper_trail on: [:create, :destroy]
+  has_paper_trail on: %i(create destroy)
 end
diff --git a/test/dummy/app/models/song.rb b/test/dummy/app/models/song.rb
index 1a118ef4..2f603a41 100644
--- a/test/dummy/app/models/song.rb
+++ b/test/dummy/app/models/song.rb
@@ -1,4 +1,21 @@
-# Example from 'Overwriting default accessors' in ActiveRecord::Base.
+module OverrideSongAttributesTheRails4Way
+  def attributes
+    if name
+      super.merge(name: name)
+    else
+      super
+    end
+  end
+
+  def changed_attributes
+    if name
+      super.merge(name: name)
+    else
+      super
+    end
+  end
+end
+
 class Song < ActiveRecord::Base
   has_paper_trail
 
@@ -15,32 +32,6 @@ class Song < ActiveRecord::Base
     attribute :name, :string
   else
     attr_accessor :name
-
-    # override attributes hashes like some libraries do
-    def attributes_with_name
-      if name
-        attributes_without_name.merge(name: name)
-      else
-        attributes_without_name
-      end
-    end
-
-    # `alias_method_chain` is deprecated in rails 5, but we cannot use the
-    # suggested replacement, `Module#prepend`, because we still support ruby 1.9.
-    alias attributes_without_name attributes
-    alias attributes attributes_with_name
-
-    def changed_attributes_with_name
-      if name
-        changed_attributes_without_name.merge(name: name)
-      else
-        changed_attributes_without_name
-      end
-    end
-
-    # `alias_method_chain` is deprecated in rails 5, but we cannot use the
-    # suggested replacement, `Module#prepend`, because we still support ruby 1.9.
-    alias changed_attributes_without_name changed_attributes
-    alias changed_attributes changed_attributes_with_name
+    prepend OverrideSongAttributesTheRails4Way
   end
 end
diff --git a/test/dummy/config/application.rb b/test/dummy/config/application.rb
index f4511be2..afd6e3e8 100644
--- a/test/dummy/config/application.rb
+++ b/test/dummy/config/application.rb
@@ -4,54 +4,24 @@ require File.expand_path("../boot", __FILE__)
 require "active_record/railtie"
 require "action_controller/railtie"
 
-Bundler.require(:default, Rails.env) if defined?(Bundler)
+Bundler.require(:default, Rails.env)
 require "paper_trail"
 
 module Dummy
   class Application < Rails::Application
-    # Settings in config/environments/* take precedence over those specified here.
-    # Application configuration should go into files in config/initializers
-    # -- all .rb files in that directory are automatically loaded.
-
-    # Custom directories with classes and modules you want to be autoloadable.
-    # config.autoload_paths += %W(#{config.root}/extras)
-
-    # Only load the plugins named here, in the order given (default is alphabetical).
-    # :all can be used as a placeholder for all plugins not explicitly named.
-    # config.plugins = [ :exception_notification, :ssl_requirement, :all ]
-
-    # Activate observers that should always be running.
-    # config.active_record.observers = :cacher, :garbage_collector, :forum_observer
-
-    # Set Time.zone default to the specified zone and make Active Record auto-convert to this zone.
-    # Run "rake -D time" for a list of tasks for finding time zone names. Default is UTC.
-    # config.time_zone = 'Central Time (US & Canada)'
-
-    # The default locale is :en and all translations from config/locales/*.rb,yml are auto loaded.
-    # config.i18n.load_path += Dir[Rails.root.join('my', 'locales', '*.{rb,yml}').to_s]
-    # config.i18n.default_locale = :de
-
-    # Configure the default encoding used in templates for Ruby 1.9.
     config.encoding = "utf-8"
-
-    # Configure sensitive parameters which will be filtered from the log file.
     config.filter_parameters += [:password]
-
-    # Enable escaping HTML in JSON.
     config.active_support.escape_html_entities_in_json = true
+    config.active_support.test_order = :sorted
 
-    # Use SQL instead of Active Record's schema dumper when creating the database.
-    # This is necessary if your schema can't be completely dumped by the schema dumper,
-    # like if you have constraints or database-specific column types
-    # config.active_record.schema_format = :sql
+    # Disable assets in rails 4.2. In rails 5, config does not respond to
+    # assets, probably because it was moved out of railties to some other gem,
+    # and we only have dev. dependencies on railties, not all of rails. When
+    # we drop support for rails 4.2, we can remove this whole conditional.
+    if config.respond_to?(:assets)
+      config.assets.enabled = false
+    end
 
-    # `config.assets` is a `NoMethodError` in rails 5.
-    config.assets.enabled = false if config.respond_to?(:assets)
-
-    # Version of your assets, change this if you want to expire all your assets
-    # config.assets.version = '1.0'
-
-    # Rails 4 key for generating secret key
     config.secret_key_base = "A fox regularly kicked the screaming pile of biscuits."
 
     # `raise_in_transactional_callbacks` was added in rails 4, then deprecated
@@ -65,8 +35,5 @@ module Dummy
         config.active_record.time_zone_aware_types = [:datetime]
       end
     end
-
-    # Set test order for Test::Unit if possible
-    config.active_support.test_order = :sorted if config.active_support.respond_to?(:test_order=)
   end
 end
diff --git a/test/dummy/config/routes.rb b/test/dummy/config/routes.rb
index 29f9452e..cef3c857 100644
--- a/test/dummy/config/routes.rb
+++ b/test/dummy/config/routes.rb
@@ -1,4 +1,4 @@
 Dummy::Application.routes.draw do
   resources :articles, only: [:create]
-  resources :widgets, only: [:create, :update, :destroy]
+  resources :widgets, only: %i(create update destroy)
 end
diff --git a/test/dummy/db/migrate/20110208155312_set_up_test_tables.rb b/test/dummy/db/migrate/20110208155312_set_up_test_tables.rb
index 026282da..c6389cfa 100644
--- a/test/dummy/db/migrate/20110208155312_set_up_test_tables.rb
+++ b/test/dummy/db/migrate/20110208155312_set_up_test_tables.rb
@@ -73,7 +73,7 @@ class SetUpTestTables < ActiveRecord::Migration
       t.string :ip
       t.string :user_agent
     end
-    add_index :versions, [:item_type, :item_id]
+    add_index :versions, %i(item_type item_id)
 
     create_table :version_associations do |t|
       t.integer  :version_id
@@ -82,7 +82,7 @@ class SetUpTestTables < ActiveRecord::Migration
     end
     add_index :version_associations, [:version_id]
     add_index :version_associations,
-      [:foreign_key_name, :foreign_key_id],
+      %i(foreign_key_name foreign_key_id),
       name: "index_version_associations_on_foreign_key"
 
     create_table :post_versions, force: true do |t|
@@ -97,7 +97,7 @@ class SetUpTestTables < ActiveRecord::Migration
       t.string :ip
       t.string :user_agent
     end
-    add_index :post_versions, [:item_type, :item_id]
+    add_index :post_versions, %i(item_type item_id)
 
     if ENV["DB"] == "postgres" && ::ActiveRecord::VERSION::MAJOR >= 4
       create_table :json_versions, force: true do |t|
@@ -109,7 +109,7 @@ class SetUpTestTables < ActiveRecord::Migration
         t.json     :object_changes
         t.datetime :created_at
       end
-      add_index :json_versions, [:item_type, :item_id]
+      add_index :json_versions, %i(item_type item_id)
     end
 
     create_table :not_on_updates, force: true do |t|
@@ -128,7 +128,7 @@ class SetUpTestTables < ActiveRecord::Migration
       t.text     :object
       t.datetime :created_at
     end
-    add_index :banana_versions, [:item_type, :item_id]
+    add_index :banana_versions, %i(item_type item_id)
 
     create_table :wotsits, force: true do |t|
       t.integer :widget_id
@@ -305,7 +305,7 @@ class SetUpTestTables < ActiveRecord::Migration
       t.text     :object
       t.datetime :created_at
     end
-    add_index :custom_primary_key_record_versions, [:item_type, :item_id], name: "idx_cust_pk_item"
+    add_index :custom_primary_key_record_versions, %i(item_type item_id), name: "idx_cust_pk_item"
   end
 
   def down
diff --git a/test/unit/associations_test.rb b/test/unit/associations_test.rb
index 1395bdb0..ae472642 100644
--- a/test/unit/associations_test.rb
+++ b/test/unit/associations_test.rb
@@ -43,10 +43,10 @@ class AssociationsTest < ActiveSupport::TestCase
       end
 
       context "when reified" do
-        setup { @widget_0 = @widget.versions.last.reify(has_one: true) }
+        setup { @widget0 = @widget.versions.last.reify(has_one: true) }
 
         should "see the associated as it was at the time" do
-          assert_nil @widget_0.wotsit
+          assert_nil @widget0.wotsit
         end
 
         should "not persist changes to the live association" do
@@ -63,10 +63,10 @@ class AssociationsTest < ActiveSupport::TestCase
       end
 
       context "when reified" do
-        setup { @widget_0 = @widget.versions.last.reify(has_one: true) }
+        setup { @widget0 = @widget.versions.last.reify(has_one: true) }
 
         should "see the associated as it was at the time" do
-          assert_equal "wotsit_0", @widget_0.wotsit.name
+          assert_equal "wotsit_0", @widget0.wotsit.name
         end
 
         should "not persist changes to the live association" do
@@ -84,10 +84,10 @@ class AssociationsTest < ActiveSupport::TestCase
         end
 
         context "when reified" do
-          setup { @widget_1 = @widget.versions.last.reify(has_one: true) }
+          setup { @widget1 = @widget.versions.last.reify(has_one: true) }
 
           should "see the associated as it was at the time" do
-            assert_equal "wotsit_2", @widget_1.wotsit.name
+            assert_equal "wotsit_2", @widget1.wotsit.name
           end
 
           should "not persist changes to the live association" do
@@ -96,10 +96,10 @@ class AssociationsTest < ActiveSupport::TestCase
         end
 
         context "when reified opting out of has_one reification" do
-          setup { @widget_1 = @widget.versions.last.reify(has_one: false) }
+          setup { @widget1 = @widget.versions.last.reify(has_one: false) }
 
           should "see the associated as it is live" do
-            assert_equal "wotsit_3", @widget_1.wotsit.name
+            assert_equal "wotsit_3", @widget1.wotsit.name
           end
         end
       end
@@ -110,10 +110,10 @@ class AssociationsTest < ActiveSupport::TestCase
         end
 
         context "when reify" do
-          setup { @widget_1 = @widget.versions.last.reify(has_one: true) }
+          setup { @widget1 = @widget.versions.last.reify(has_one: true) }
 
           should "see the associated as it was at the time" do
-            assert_equal @wotsit, @widget_1.wotsit
+            assert_equal @wotsit, @widget1.wotsit
           end
 
           should "not persist changes to the live association" do
@@ -128,10 +128,10 @@ class AssociationsTest < ActiveSupport::TestCase
           end
 
           context "when reified" do
-            setup { @widget_2 = @widget.versions.last.reify(has_one: true) }
+            setup { @widget2 = @widget.versions.last.reify(has_one: true) }
 
             should "see the associated as it was at the time" do
-              assert_nil @widget_2.wotsit
+              assert_nil @widget2.wotsit
             end
           end
         end
@@ -149,10 +149,10 @@ class AssociationsTest < ActiveSupport::TestCase
       end
 
       context "when reified" do
-        setup { @customer_0 = @customer.versions.last.reify(has_many: true) }
+        setup { @customer0 = @customer.versions.last.reify(has_many: true) }
 
         should "see the associated as it was at the time" do
-          assert_equal [], @customer_0.orders
+          assert_equal [], @customer0.orders
         end
 
         should "not persist changes to the live association" do
@@ -162,11 +162,11 @@ class AssociationsTest < ActiveSupport::TestCase
 
       context "when reified with option mark_for_destruction" do
         should "mark the associated for destruction" do
-          @customer_0 = @customer.versions.last.reify(
+          @customer0 = @customer.versions.last.reify(
             has_many: true,
             mark_for_destruction: true
           )
-          assert_equal [true], @customer_0.orders.map(&:marked_for_destruction?)
+          assert_equal [true], @customer0.orders.map(&:marked_for_destruction?)
         end
       end
     end
@@ -179,10 +179,10 @@ class AssociationsTest < ActiveSupport::TestCase
       end
 
       context "when reified" do
-        setup { @customer_0 = @customer.versions.last.reify(has_many: true) }
+        setup { @customer0 = @customer.versions.last.reify(has_many: true) }
 
         should "see the associated as it was at the time" do
-          assert_equal ["order_date_0"], @customer_0.orders.map(&:order_date)
+          assert_equal ["order_date_0"], @customer0.orders.map(&:order_date)
         end
       end
 
@@ -192,10 +192,10 @@ class AssociationsTest < ActiveSupport::TestCase
         end
 
         context "when reified" do
-          setup { @customer_0 = @customer.versions.last.reify(has_many: true) }
+          setup { @customer0 = @customer.versions.last.reify(has_many: true) }
 
           should "see the live version of the nested association" do
-            assert_equal ["product_0"], @customer_0.orders.first.line_items.map(&:product)
+            assert_equal ["product_0"], @customer0.orders.first.line_items.map(&:product)
           end
         end
       end
@@ -210,10 +210,10 @@ class AssociationsTest < ActiveSupport::TestCase
         end
 
         context "when reified" do
-          setup { @customer_1 = @customer.versions.last.reify(has_many: true) }
+          setup { @customer1 = @customer.versions.last.reify(has_many: true) }
 
           should "see the associated as it was at the time" do
-            assert_equal ["order_date_2"], @customer_1.orders.map(&:order_date)
+            assert_equal ["order_date_2"], @customer1.orders.map(&:order_date)
           end
 
           should "not persist changes to the live association" do
@@ -222,10 +222,10 @@ class AssociationsTest < ActiveSupport::TestCase
         end
 
         context "when reified opting out of has_many reification" do
-          setup { @customer_1 = @customer.versions.last.reify(has_many: false) }
+          setup { @customer1 = @customer.versions.last.reify(has_many: false) }
 
           should "see the associated as it is live" do
-            assert_equal ["order_date_3"], @customer_1.orders.map(&:order_date)
+            assert_equal ["order_date_3"], @customer1.orders.map(&:order_date)
           end
         end
 
@@ -235,10 +235,10 @@ class AssociationsTest < ActiveSupport::TestCase
           end
 
           context "when reified" do
-            setup { @customer_1 = @customer.versions.last.reify(has_many: true) }
+            setup { @customer1 = @customer.versions.last.reify(has_many: true) }
 
             should "see the associated as it was at the time" do
-              assert_equal ["order_date_2"], @customer_1.orders.map(&:order_date)
+              assert_equal ["order_date_2"], @customer1.orders.map(&:order_date)
             end
 
             should "not persist changes to the live association" do
@@ -254,10 +254,10 @@ class AssociationsTest < ActiveSupport::TestCase
         end
 
         context "when reified" do
-          setup { @customer_1 = @customer.versions.last.reify(has_many: true) }
+          setup { @customer1 = @customer.versions.last.reify(has_many: true) }
 
           should "see the associated as it was at the time" do
-            assert_equal [@order.order_date], @customer_1.orders.map(&:order_date)
+            assert_equal [@order.order_date], @customer1.orders.map(&:order_date)
           end
 
           should "not persist changes to the live association" do
@@ -274,10 +274,10 @@ class AssociationsTest < ActiveSupport::TestCase
         end
 
         context "when reified" do
-          setup { @customer_1 = @customer.versions.last.reify(has_many: true) }
+          setup { @customer1 = @customer.versions.last.reify(has_many: true) }
 
           should "see the associated as it was at the time" do
-            assert_equal [], @customer_1.orders
+            assert_equal [], @customer1.orders
           end
         end
       end
@@ -288,10 +288,10 @@ class AssociationsTest < ActiveSupport::TestCase
         end
 
         context "when reified" do
-          setup { @customer_0 = @customer.versions.last.reify(has_many: true) }
+          setup { @customer0 = @customer.versions.last.reify(has_many: true) }
 
           should "see the associated as it was at the time" do
-            assert_equal ["order_date_0"], @customer_0.orders.map(&:order_date)
+            assert_equal ["order_date_0"], @customer0.orders.map(&:order_date)
           end
 
           should "not persist changes to the live association" do
@@ -302,11 +302,11 @@ class AssociationsTest < ActiveSupport::TestCase
 
         context "when reified with option mark_for_destruction" do
           should "mark the newly associated for destruction" do
-            @customer_0 = @customer.versions.last.reify(
+            @customer0 = @customer.versions.last.reify(
               has_many: true,
               mark_for_destruction: true
             )
-            assert @customer_0.
+            assert @customer0.
               orders.
               detect { |o| o.order_date == "order_date_1" }.
               marked_for_destruction?
@@ -327,10 +327,10 @@ class AssociationsTest < ActiveSupport::TestCase
         end
 
         context "when reified" do
-          setup { @book_0 = @book.versions.last.reify(has_many: true) }
+          setup { @book0 = @book.versions.last.reify(has_many: true) }
 
           should "see the associated as it was at the time" do
-            assert_equal [], @book_0.authors
+            assert_equal [], @book0.authors
           end
 
           should "not persist changes to the live association" do
@@ -340,18 +340,18 @@ class AssociationsTest < ActiveSupport::TestCase
 
         context "when reified with option mark_for_destruction" do
           setup do
-            @book_0 = @book.versions.last.reify(
+            @book0 = @book.versions.last.reify(
               has_many: true,
               mark_for_destruction: true
             )
           end
 
           should "mark the associated for destruction" do
-            assert_equal [true], @book_0.authors.map(&:marked_for_destruction?)
+            assert_equal [true], @book0.authors.map(&:marked_for_destruction?)
           end
 
           should "mark the associated-through for destruction" do
-            assert_equal [true], @book_0.authorships.map(&:marked_for_destruction?)
+            assert_equal [true], @book0.authorships.map(&:marked_for_destruction?)
           end
         end
       end
@@ -366,28 +366,28 @@ class AssociationsTest < ActiveSupport::TestCase
 
         context "when reified" do
           setup do
-            @book_0 = @book.versions.last.reify(has_many: true)
+            @book0 = @book.versions.last.reify(has_many: true)
           end
 
           should "see the associated as it was at the time" do
-            assert_equal [], @book_0.authors
+            assert_equal [], @book0.authors
           end
         end
 
         context "when reified with option mark_for_destruction" do
           setup do
-            @book_0 = @book.versions.last.reify(
+            @book0 = @book.versions.last.reify(
               has_many: true,
               mark_for_destruction: true
             )
           end
 
           should "not mark the associated for destruction" do
-            assert_equal [false], @book_0.authors.map(&:marked_for_destruction?)
+            assert_equal [false], @book0.authors.map(&:marked_for_destruction?)
           end
 
           should "mark the associated-through for destruction" do
-            assert_equal [true], @book_0.authorships.map(&:marked_for_destruction?)
+            assert_equal [true], @book0.authorships.map(&:marked_for_destruction?)
           end
         end
       end
@@ -401,10 +401,10 @@ class AssociationsTest < ActiveSupport::TestCase
         end
 
         context "when reified" do
-          setup { @book_0 = @book.versions.last.reify(has_many: true) }
+          setup { @book0 = @book.versions.last.reify(has_many: true) }
 
           should "see the associated as it was at the time" do
-            assert_equal ["author_0"], @book_0.authors.map(&:name)
+            assert_equal ["author_0"], @book0.authors.map(&:name)
           end
         end
 
@@ -418,10 +418,10 @@ class AssociationsTest < ActiveSupport::TestCase
           end
 
           context "when reified" do
-            setup { @book_1 = @book.versions.last.reify(has_many: true) }
+            setup { @book1 = @book.versions.last.reify(has_many: true) }
 
             should "see the associated as it was at the time" do
-              assert_equal ["author_2"], @book_1.authors.map(&:name)
+              assert_equal ["author_2"], @book1.authors.map(&:name)
             end
 
             should "not persist changes to the live association" do
@@ -430,10 +430,10 @@ class AssociationsTest < ActiveSupport::TestCase
           end
 
           context "when reified opting out of has_many reification" do
-            setup { @book_1 = @book.versions.last.reify(has_many: false) }
+            setup { @book1 = @book.versions.last.reify(has_many: false) }
 
             should "see the associated as it is live" do
-              assert_equal ["author_3"], @book_1.authors.map(&:name)
+              assert_equal ["author_3"], @book1.authors.map(&:name)
             end
           end
         end
@@ -444,10 +444,10 @@ class AssociationsTest < ActiveSupport::TestCase
           end
 
           context "when reified" do
-            setup { @book_1 = @book.versions.last.reify(has_many: true) }
+            setup { @book1 = @book.versions.last.reify(has_many: true) }
 
             should "see the associated as it was at the time" do
-              assert_equal [@author.name], @book_1.authors.map(&:name)
+              assert_equal [@author.name], @book1.authors.map(&:name)
             end
 
             should "not persist changes to the live association" do
@@ -464,10 +464,10 @@ class AssociationsTest < ActiveSupport::TestCase
           end
 
           context "when reified" do
-            setup { @book_1 = @book.versions.last.reify(has_many: true) }
+            setup { @book1 = @book.versions.last.reify(has_many: true) }
 
             should "see the associated as it was at the time" do
-              assert_equal [], @book_1.authors
+              assert_equal [], @book1.authors
             end
           end
         end
@@ -480,10 +480,10 @@ class AssociationsTest < ActiveSupport::TestCase
           end
 
           context "when reified" do
-            setup { @book_1 = @book.versions.last.reify(has_many: true) }
+            setup { @book1 = @book.versions.last.reify(has_many: true) }
 
             should "see the associated as it was at the time" do
-              assert_equal [], @book_1.authors
+              assert_equal [], @book1.authors
             end
           end
         end
@@ -494,10 +494,10 @@ class AssociationsTest < ActiveSupport::TestCase
           end
 
           context "when reified" do
-            setup { @book_0 = @book.versions.last.reify(has_many: true) }
+            setup { @book0 = @book.versions.last.reify(has_many: true) }
 
             should "only see the first associated" do
-              assert_equal ["author_0"], @book_0.authors.map(&:name)
+              assert_equal ["author_0"], @book0.authors.map(&:name)
             end
 
             should "not persist changes to the live association" do
@@ -507,21 +507,21 @@ class AssociationsTest < ActiveSupport::TestCase
 
           context "when reified with option mark_for_destruction" do
             setup do
-              @book_0 = @book.versions.last.reify(
+              @book0 = @book.versions.last.reify(
                 has_many: true,
                 mark_for_destruction: true
               )
             end
 
             should "mark the newly associated for destruction" do
-              assert @book_0.
+              assert @book0.
                 authors.
                 detect { |a| a.name == "author_1" }.
                 marked_for_destruction?
             end
 
             should "mark the newly associated-through for destruction" do
-              assert @book_0.
+              assert @book0.
                 authorships.
                 detect { |as| as.author.name == "author_1" }.
                 marked_for_destruction?
@@ -535,10 +535,10 @@ class AssociationsTest < ActiveSupport::TestCase
           end
 
           context "when reified" do
-            setup { @book_0 = @book.versions.last.reify(has_many: true) }
+            setup { @book0 = @book.versions.last.reify(has_many: true) }
 
             should "only see the first associated" do
-              assert_equal ["author_0"], @book_0.authors.map(&:name)
+              assert_equal ["author_0"], @book0.authors.map(&:name)
             end
 
             should "not persist changes to the live association" do
@@ -548,21 +548,21 @@ class AssociationsTest < ActiveSupport::TestCase
 
           context "when reified with option mark_for_destruction" do
             setup do
-              @book_0 = @book.versions.last.reify(
+              @book0 = @book.versions.last.reify(
                 has_many: true,
                 mark_for_destruction: true
               )
             end
 
             should "not mark the newly associated for destruction" do
-              assert !@book_0.
+              assert !@book0.
                 authors.
                 detect { |a| a.name == "person_existing" }.
                 marked_for_destruction?
             end
 
             should "mark the newly associated-through for destruction" do
-              assert @book_0.
+              assert @book0.
                 authorships.
                 detect { |as| as.author.name == "person_existing" }.
                 marked_for_destruction?
@@ -578,10 +578,10 @@ class AssociationsTest < ActiveSupport::TestCase
         end
 
         context "when reified" do
-          setup { @book_0 = @book.versions.last.reify(has_many: true) }
+          setup { @book0 = @book.versions.last.reify(has_many: true) }
 
           should "see the live association" do
-            assert_equal ["editor_0"], @book_0.editors.map(&:name)
+            assert_equal ["editor_0"], @book0.editors.map(&:name)
           end
         end
       end
@@ -782,10 +782,10 @@ class AssociationsTest < ActiveSupport::TestCase
         end
 
         context "when reified" do
-          setup { @wotsit_0 = @wotsit.versions.last.reify(belongs_to: true) }
+          setup { @wotsit0 = @wotsit.versions.last.reify(belongs_to: true) }
 
           should "see the associated as it was at the time" do
-            assert_nil @wotsit_0.widget
+            assert_nil @wotsit0.widget
           end
 
           should "not persist changes to the live association" do
@@ -803,10 +803,10 @@ class AssociationsTest < ActiveSupport::TestCase
           end
 
           context "when reified" do
-            setup { @wotsit_1 = @wotsit.versions.last.reify(belongs_to: true) }
+            setup { @wotsit1 = @wotsit.versions.last.reify(belongs_to: true) }
 
             should "see the associated as it was at the time" do
-              assert_equal "widget_2", @wotsit_1.widget.name
+              assert_equal "widget_2", @wotsit1.widget.name
             end
 
             should "not persist changes to the live association" do
@@ -815,10 +815,10 @@ class AssociationsTest < ActiveSupport::TestCase
           end
 
           context "when reified opting out of belongs_to reification" do
-            setup { @wotsit_1 = @wotsit.versions.last.reify(belongs_to: false) }
+            setup { @wotsit1 = @wotsit.versions.last.reify(belongs_to: false) }
 
             should "see the associated as it is live" do
-              assert_equal "widget_3", @wotsit_1.widget.name
+              assert_equal "widget_3", @wotsit1.widget.name
             end
           end
         end
@@ -830,10 +830,10 @@ class AssociationsTest < ActiveSupport::TestCase
           end
 
           context "when reified" do
-            setup { @wotsit_2 = @wotsit.versions.last.reify(belongs_to: true) }
+            setup { @wotsit2 = @wotsit.versions.last.reify(belongs_to: true) }
 
             should "see the associated as it was at the time" do
-              assert_equal @widget, @wotsit_2.widget
+              assert_equal @widget, @wotsit2.widget
             end
 
             should "not persist changes to the live association" do
@@ -848,10 +848,10 @@ class AssociationsTest < ActiveSupport::TestCase
             end
 
             context "when reified" do
-              setup { @wotsit_2 = @wotsit.versions.last.reify(belongs_to: true) }
+              setup { @wotsit2 = @wotsit.versions.last.reify(belongs_to: true) }
 
               should "see the associated as it was the time" do
-                assert_nil @wotsit_2.widget
+                assert_nil @wotsit2.widget
               end
             end
           end
@@ -867,10 +867,10 @@ class AssociationsTest < ActiveSupport::TestCase
         end
 
         context "when reified" do
-          setup { @wotsit_0 = @wotsit.versions.last.reify(belongs_to: true) }
+          setup { @wotsit0 = @wotsit.versions.last.reify(belongs_to: true) }
 
           should "see the association as it was at the time" do
-            assert_equal "widget_0", @wotsit_0.widget.name
+            assert_equal "widget_0", @wotsit0.widget.name
           end
 
           should "not persist changes to the live association" do
@@ -880,7 +880,7 @@ class AssociationsTest < ActiveSupport::TestCase
 
         context "when reified with option mark_for_destruction" do
           setup do
-            @wotsit_0 = @wotsit.versions.last.
+            @wotsit0 = @wotsit.versions.last.
               reify(belongs_to: true, mark_for_destruction: true)
           end