DEV: Improve code comment about when ignored columns can be removed (#26894)

Ignored columns can only be dropped when its associated post-deploy
migration has been promoted to a regular migration. This is so because
Discourse doesn't rely on a schema file system to setup a brand new
database and thus the column information will be loaded by the
application first before the post-deploy migration runs.

app/models/category.rb

@@ -4,9 +4,9 @@ class Category < ActiveRecord::Base
   RESERVED_SLUGS = ["none"]
 
   self.ignored_columns = [
-    :suppress_from_latest, # TODO(2020-11-18): remove
+    :suppress_from_latest, # TODO: Remove when 20240212034010_drop_deprecated_columns has been promoted to pre-deploy
-    :required_tag_group_id, # TODO(2023-04-01): remove
+    :required_tag_group_id, # TODO: Remove when 20240212034010_drop_deprecated_columns has been promoted to pre-deploy
-    :min_tags_from_required_group, # TODO(2023-04-01): remove
+    :min_tags_from_required_group, # TODO: Remove when 20240212034010_drop_deprecated_columns has been promoted to pre-deploy
   ]
 
   include Searchable

app/models/directory_column.rb

@@ -1,8 +1,7 @@
 # frozen_string_literal: true
 
 class DirectoryColumn < ActiveRecord::Base
-  # TODO(2021-06-18): Remove automatic column
+  self.ignored_columns = ["automatic"] # TODO: Remove when 20240212034010_drop_deprecated_columns has been promoted to pre-deploy
-  self.ignored_columns = ["automatic"]
   self.inheritance_column = nil
 
   enum type: { automatic: 0, user_field: 1, plugin: 2 }, _scopes: false

app/models/email_token.rb

@@ -40,8 +40,7 @@ class EmailToken < ActiveRecord::Base
     end
   end
 
-  # TODO(2022-01-01): Remove
+  self.ignored_columns = %w[token] # TODO: Remove when 20240212034010_drop_deprecated_columns has been promoted to pre-deploy
-  self.ignored_columns = %w[token]
 
   def self.scopes
     @scopes ||= Enum.new(signup: 1, password_reset: 2, email_login: 3, email_update: 4)

app/models/embeddable_host.rb

@@ -10,8 +10,7 @@ class EmbeddableHost < ActiveRecord::Base
     self.host.sub!(%r{/.*\z}, "")
   end
 
-  # TODO(2021-07-23): Remove
+  self.ignored_columns = ["path_whitelist"] # TODO: Remove when 20240212034010_drop_deprecated_columns has been promoted to pre-deploy
-  self.ignored_columns = ["path_whitelist"]
 
   def self.record_for_url(uri)
     if uri.is_a?(String)

app/models/group.rb

@@ -3,8 +3,7 @@
 require "net/imap"
 
 class Group < ActiveRecord::Base
-  # TODO(2021-05-26): remove
+  self.ignored_columns = %w[flair_url] # TODO: Remove when 20240212034010_drop_deprecated_columns has been promoted to pre-deploy
-  self.ignored_columns = %w[flair_url]
 
   include HasCustomFields
   include AnonCacheInvalidator

app/models/invite.rb

@@ -13,8 +13,7 @@ class Invite < ActiveRecord::Base
   include RateLimiter::OnCreateRecord
   include Trashable
 
-  # TODO(2021-05-22): remove
+  self.ignored_columns = %w[user_id redeemed_at] # TODO: Remove when 20240212034010_drop_deprecated_columns has been promoted to pre-deploy
-  self.ignored_columns = %w[user_id redeemed_at]
 
   BULK_INVITE_EMAIL_LIMIT = 200
   DOMAIN_REGEX =

app/models/post.rb

@@ -11,8 +11,8 @@ class Post < ActiveRecord::Base
   include LimitedEdit
 
   self.ignored_columns = [
-    "avg_time", # TODO(2021-01-04): remove
+    "avg_time", # TODO: Remove when 20240212034010_drop_deprecated_columns has been promoted to pre-deploy
-    "image_url", # TODO(2021-06-01): remove
+    "image_url", # TODO: Remove when 20240212034010_drop_deprecated_columns has been promoted to pre-deploy
   ]
 
   cattr_accessor :plugin_permitted_create_params, :plugin_permitted_update_params

app/models/tag.rb

@@ -6,7 +6,7 @@ class Tag < ActiveRecord::Base
   include HasSanitizableFields
 
   self.ignored_columns = [
-    "topic_count", # TODO(tgxworld): Remove on 1 July 2023
+    "topic_count", # TODO: Remove when 20240212034010_drop_deprecated_columns has been promoted to pre-deploy
   ]
 
   RESERVED_TAGS = [

app/models/topic.rb

@@ -16,8 +16,8 @@ class Topic < ActiveRecord::Base
   EXTERNAL_ID_MAX_LENGTH = 50
 
   self.ignored_columns = [
-    "avg_time", # TODO(2021-01-04): remove
+    "avg_time", # TODO: Remove when 20240212034010_drop_deprecated_columns has been promoted to pre-deploy
-    "image_url", # TODO(2021-06-01): remove
+    "image_url", # TODO: Remove when 20240212034010_drop_deprecated_columns has been promoted to pre-deploy
   ]
 
   def_delegator :featured_users, :user_ids, :featured_user_ids

app/models/topic_user.rb

@@ -2,7 +2,7 @@
 
 class TopicUser < ActiveRecord::Base
   self.ignored_columns = [
-    :highest_seen_post_number, # Remove after 01 Jan 2022
+    :highest_seen_post_number, # TODO: Remove when 20240212034010_drop_deprecated_columns has been promoted to pre-deploy
   ]
 
   belongs_to :user

app/models/user_api_key.rb

@@ -2,7 +2,7 @@
 
 class UserApiKey < ActiveRecord::Base
   self.ignored_columns = [
-    "scopes", # TODO(2020-12-18): remove
+    "scopes", # TODO: Remove when 20240212034010_drop_deprecated_columns has been promoted to pre-deploy
   ]
 
   REVOKE_MATCHER = RouteMatcher.new(actions: "user_api_keys#revoke", methods: :post, params: [:id])

app/models/user_option.rb

@@ -14,8 +14,7 @@ class UserOption < ActiveRecord::Base
   }
 
   self.ignored_columns = [
-    "disable_jump_reply", # Remove once 20210706091905 is promoted from post_deploy to regular migration
+    "sidebar_list_destination", # TODO: Remove when 20240212034010_drop_deprecated_columns has been promoted to pre-deploy
-    "sidebar_list_destination", # TODO(osama): Remove in January 2024
   ]
 
   self.primary_key = :user_id

app/models/user_profile.rb

@@ -1,8 +1,7 @@
 # frozen_string_literal: true
 
 class UserProfile < ActiveRecord::Base
-  # TODO Remove `badge_granted_title` after 2023-09-01
+  self.ignored_columns = ["badge_granted_title"] # TODO: Remove when 20240212034010_drop_deprecated_columns has been promoted to pre-deploy
-  self.ignored_columns = ["badge_granted_title"]
 
   BAKED_VERSION = 1
 

app/models/user_stat.rb

@@ -3,8 +3,7 @@ class UserStat < ActiveRecord::Base
   belongs_to :user
   after_save :trigger_badges
 
-  # TODO(2021-05-13): Remove
+  self.ignored_columns = ["topic_reply_count"] # TODO: Remove when 20240212034010_drop_deprecated_columns has been promoted to pre-deploy
-  self.ignored_columns = ["topic_reply_count"]
 
   def self.ensure_consistency!(last_seen = 1.hour.ago)
     reset_bounce_scores

lib/migration/safe_migrate.rb

@@ -141,7 +141,7 @@ class Migration::SafeMigrate
         or rename columns.
 
         Note, to minimize disruption use self.ignored_columns = ["column name"] on your
-        ActiveRecord model, this can be removed 6 months or so later.
+        ActiveRecord model, this can be removed after the post deployment migration has been promoted to a regular migration.
 
         This protection is in place to protect us against dropping columns that are currently
         in use by live applications.