chore: Use find_each instead of .all.each (#6975)

- Enable the rubocop Rails/FindEach
- Replace the .all.each with .find_each

This should let us avoid potential memory usage.
Motivation from the speedshop newsletter by Nate Berkopec

ref: https://www.rubyinrails.com/2017/11/16/use-find-each-instead-of-all-each-in-rails/
ref: https://linear.app/chatwoot/issue/CW-1480/chore-run-all-sidekiq-jobs-async

.rubocop.yml

@@ -71,6 +71,10 @@ Rails/ApplicationController:
     - 'app/controllers/platform_controller.rb'
     - 'app/controllers/public_controller.rb'
     - 'app/controllers/survey/responses_controller.rb'
+Rails/FindEach:
+  Enabled: true
+  Include: 
+    - 'app/**/*.rb'
 Rails/CompactBlank:
   Enabled: false
 Rails/EnvironmentVariableAccess:

app/jobs/account/conversations_resolution_scheduler_job.rb

@@ -2,7 +2,7 @@ class Account::ConversationsResolutionSchedulerJob < ApplicationJob
   queue_as :scheduled_jobs
 
   def perform
-    Account.where.not(auto_resolve_duration: nil).all.each do |account|
+    Account.where.not(auto_resolve_duration: nil).all.find_each(batch_size: 100) do |account|
       Conversations::ResolutionJob.perform_later(account: account)
     end
   end

app/jobs/conversations/reopen_snoozed_conversations_job.rb

@@ -2,6 +2,6 @@ class Conversations::ReopenSnoozedConversationsJob < ApplicationJob
   queue_as :low
 
   def perform
-    Conversation.where(status: :snoozed).where(snoozed_until: 3.days.ago..Time.current).all.each(&:open!)
+    Conversation.where(status: :snoozed).where(snoozed_until: 3.days.ago..Time.current).all.find_each(batch_size: 100, &:open!)
   end
 end

app/jobs/inboxes/fetch_imap_email_inboxes_job.rb

@@ -2,7 +2,7 @@ class Inboxes::FetchImapEmailInboxesJob < ApplicationJob
   queue_as :low
 
   def perform
-    Inbox.where(channel_type: 'Channel::Email').all.each do |inbox|
+    Inbox.where(channel_type: 'Channel::Email').all.find_each(batch_size: 100) do |inbox|
       ::Inboxes::FetchImapEmailsJob.perform_later(inbox.channel) if inbox.channel.imap_enabled
     end
   end

app/jobs/migration/update_first_response_time_in_reporting_events_job.rb

@@ -6,7 +6,7 @@ class Migration::UpdateFirstResponseTimeInReportingEventsJob < ApplicationJob
 
   def perform(account)
     get_conversations_with_bot_handoffs(account)
-    account.reporting_events.where(name: 'first_response').each do |event|
+    account.reporting_events.where(name: 'first_response').find_each do |event|
       conversation = event.conversation
 
       # if the conversation has a bot handoff event, we don't need to update the response_time

app/jobs/trigger_scheduled_items_job.rb

@@ -3,7 +3,8 @@ class TriggerScheduledItemsJob < ApplicationJob
 
   def perform
     # trigger the scheduled campaign jobs
-    Campaign.where(campaign_type: :one_off, campaign_status: :active).where(scheduled_at: 3.days.ago..Time.current).all.each do |campaign|
+    Campaign.where(campaign_type: :one_off,
+                   campaign_status: :active).where(scheduled_at: 3.days.ago..Time.current).all.find_each(batch_size: 100) do |campaign|
       Campaigns::TriggerOneoffCampaignJob.perform_later(campaign)
     end
 

spec/controllers/api/v1/accounts/bulk_actions_controller_spec.rb

@@ -12,7 +12,7 @@ RSpec.describe 'Api::V1::Accounts::BulkActionsController', type: :request do
     create(:conversation, account_id: account.id, status: :open, team_id: team_1.id)
     create(:conversation, account_id: account.id, status: :open)
     create(:conversation, account_id: account.id, status: :open)
-    Conversation.all.each do |conversation|
+    Conversation.all.find_each do |conversation|
       create(:inbox_member, inbox: conversation.inbox, user: agent_1)
       create(:inbox_member, inbox: conversation.inbox, user: agent_2)
     end

spec/jobs/bulk_actions_job_spec.rb

@@ -16,7 +16,7 @@ RSpec.describe BulkActionsJob, type: :job do
   let!(:conversation_3) { create(:conversation, account_id: account.id, status: :open) }
 
   before do
-    Conversation.all.each do |conversation|
+    Conversation.all.find_each do |conversation|
       create(:inbox_member, inbox: conversation.inbox, user: agent)
     end
   end

spec/jobs/inboxes/fetch_imap_email_inboxes_job_spec.rb

@@ -15,10 +15,6 @@ RSpec.describe Inboxes::FetchImapEmailInboxesJob, type: :job do
 
   context 'when called' do
     it 'fetch all the email channels' do
-      imap_email_inboxes = double
-      allow(imap_email_inboxes).to receive(:all).and_return([email_inbox])
-      allow(Inbox).to receive(:where).and_return(imap_email_inboxes)
-
       expect(Inboxes::FetchImapEmailsJob).to receive(:perform_later).with(imap_email_channel).once
 
       described_class.perform_now