Validate detected instance_variable is an ActiveRecord::Relation

lib/bulletmark_repairer/markers.rb

@@ -82,15 +82,15 @@ def set_up
         end
         view_file, view_yield_index = @stacktraces[view_file_index].scan(%r{\A(/[./\w]+):(\d+):in `[\w]+'\z}).flatten
         view_yield_index = view_yield_index.to_i
-        # TODO: Compile views
         File.open(view_file) do |f|
           lines = f.readlines
           loop do
             break if @instance_variable_name || view_yield_index.zero?
 
             view_yield_index -= 1
             line = lines[view_yield_index]
-            @instance_variable_name = line&.scan(/\b?(@[\w]+)\b?/)&.flatten&.last
+            token = line&.scan(/\b?(@[\w]+)\b?/)&.flatten&.last
+            @instance_variable_name = token if BulletmarkRepairer::Thread.instance_variable_name?(token)
           end
         end
         @index = @instance_variable_name ? "#{view_file}:#{view_yield_index}" : nil

lib/bulletmark_repairer/monkey_patches/action_view/base.rb

@@ -0,0 +1,14 @@
+# frozen_string_literal: true
+
+module BulletmarkRepairer
+  module ActionView
+    module Base
+      def initialize(*args)
+        super(*args)
+        @_assigns.each do |ivname, value|
+          BulletmarkRepairer::Thread.memorize_instance_variable_name(name: ivname, value: value)
+        end
+      end
+    end
+  end
+end

lib/bulletmark_repairer/railtie.rb

@@ -14,5 +14,9 @@ class Railtie < ::Rails::Railtie
       require 'bulletmark_repairer/monkey_patches/active_record/query_method'
       ::ActiveRecord::Relation.prepend(BulletmarkRepairer::ActiveRecord::QueryMethod)
     end
+    ActiveSupport.on_load(:action_view) do
+      require 'bulletmark_repairer/monkey_patches/action_view/base'
+      ::ActionView::Base.prepend(BulletmarkRepairer::ActionView::Base)
+    end
   end
 end

lib/bulletmark_repairer/thread.rb

@@ -13,6 +13,16 @@ def memorize_associations(name:, method_type:, args:)
         current(:loaded_associations)[name][method_type].add(args)
       end
 
+      def memorize_instance_variable_name(name:, value:)
+        return unless value.is_a?(::ActiveRecord::Relation)
+
+        current(:loaded_instance_variables).add("@#{name}")
+      end
+
+      def instance_variable_name?(name)
+        current(:loaded_instance_variables).include?(name)
+      end
+
       def clear
         ::Thread.current[:bulletmark_repairer] = nil
       end

spec/fake_app/app/controllers/instance_variables_controller.rb

@@ -0,0 +1,8 @@
+# frozen_string_literal: true
+
+class InstanceVariablesController < ActionController::Base
+  def index
+    @favorite = true
+    @plays = Play.all
+  end
+end

spec/fake_app/app/views/instance_variables/index.html.erb

@@ -0,0 +1,8 @@
+<% plays = @plays %>
+<% if @favorite %>
+  <% plays.each do |play| %>
+    <% play.actors.each do |actor| %>
+      <%= actor.name %>
+    <% end %>
+  <% end %>
+<% end %>

spec/fake_app/config/routes.rb

@@ -18,5 +18,6 @@
   resources :multiple_nested_though_only_grand_child_is_required_includes, only: [:index]
   resources :another_name_associations, only: [:index]
   resources :nested_and_another_name_includes, only: [:index]
+  resources :instance_variables, only: [:index]
   resources :avoid_includes, only: [:index]
 end

spec/requests/instance_variables_spec.rb

@@ -0,0 +1,31 @@
+# frozen_string_literal: true
+
+require 'rails_helper'
+
+RSpec.describe InstanceVariablesController do
+  let(:original_src) do
+    <<-SRC
+  def index
+    @favorite = true
+    @plays = Play.all
+  end
+    SRC
+  end
+  let(:patched_src) do
+    <<-SRC
+  def index
+    @favorite = true
+    @plays = Play.all.includes([:actors])
+  end
+    SRC
+  end
+
+  before do
+    create(:play, :blast)
+    create(:play, :crescent_wolf)
+  end
+
+  subject { get instance_variables_path }
+
+  it_behaves_like 'correctly patched'
+end