Change how hashtags are normalized (#18795)

* Change how hashtags are normalized

* Fix tests

5 files changed, 43 insertions, 20 deletions

diff --git a/app/models/account.rb b/app/models/account.rb
index 628692d22..fe77eaec4 100644
--- a/app/models/account.rb
+++ b/app/models/account.rb
@@ -62,7 +62,7 @@ class Account < ApplicationRecord
   )
 
   USERNAME_RE   = /[a-z0-9_]+([a-z0-9_\.-]+[a-z0-9_]+)?/i
-  MENTION_RE    = /(?<=^|[^\/[:word:]])@((#{USERNAME_RE})(?:@[[:word:]\.\-]+[[:word:]]+)?)/i
+  MENTION_RE    = /(?<=^|[^\/[:word:]])@((#{USERNAME_RE})(?:@[[:alnum:]\.\-]+[[:alnum:]]+)?)/i
   URL_PREFIX_RE = /\Ahttp(s?):\/\/[^\/]+/
 
   include Attachmentable
diff --git a/app/models/custom_filter.rb b/app/models/custom_filter.rb
index e98ed7df9..985eab125 100644
--- a/app/models/custom_filter.rb
+++ b/app/models/custom_filter.rb
@@ -3,14 +3,14 @@
 #
 # Table name: custom_filters
 #
-#  id         :bigint           not null, primary key
-#  account_id :bigint
+#  id         :bigint(8)        not null, primary key
+#  account_id :bigint(8)
 #  expires_at :datetime
 #  phrase     :text             default(""), not null
 #  context    :string           default([]), not null, is an Array
 #  created_at :datetime         not null
 #  updated_at :datetime         not null
-#  action     :integer          default(0), not null
+#  action     :integer          default("warn"), not null
 #
 
 class CustomFilter < ApplicationRecord
diff --git a/app/models/custom_filter_keyword.rb b/app/models/custom_filter_keyword.rb
index bf5c55746..e0d0289ae 100644
--- a/app/models/custom_filter_keyword.rb
+++ b/app/models/custom_filter_keyword.rb
@@ -3,8 +3,8 @@
 #
 # Table name: custom_filter_keywords
 #
-#  id               :bigint           not null, primary key
-#  custom_filter_id :bigint           not null
+#  id               :bigint(8)        not null, primary key
+#  custom_filter_id :bigint(8)        not null
 #  keyword          :text             default(""), not null
 #  whole_word       :boolean          default(TRUE), not null
 #  created_at       :datetime         not null
diff --git a/app/models/featured_tag.rb b/app/models/featured_tag.rb
index 74d62e777..c9c285bfa 100644
--- a/app/models/featured_tag.rb
+++ b/app/models/featured_tag.rb
@@ -13,17 +13,19 @@
 #
 
 class FeaturedTag < ApplicationRecord
-  belongs_to :account, inverse_of: :featured_tags, required: true
-  belongs_to :tag, inverse_of: :featured_tags, required: true
+  belongs_to :account, inverse_of: :featured_tags
+  belongs_to :tag, inverse_of: :featured_tags, optional: true # Set after validation
 
-  delegate :name, to: :tag, allow_nil: true
-
-  validates_associated :tag, on: :create
-  validates :name, presence: true, on: :create
+  validate :validate_tag_name, on: :create
   validate :validate_featured_tags_limit, on: :create
 
-  def name=(str)
-    self.tag = Tag.find_or_create_by_names(str.strip)&.first
+  before_create :set_tag
+  before_create :reset_data
+
+  attr_writer :name
+
+  def name
+    tag_id.present? ? tag.name : @name
   end
 
   def increment(timestamp)
@@ -34,14 +36,23 @@ class FeaturedTag < ApplicationRecord
     update(statuses_count: [0, statuses_count - 1].max, last_status_at: account.statuses.where(visibility: %i(public unlisted)).tagged_with(tag).where.not(id: deleted_status_id).select(:created_at).first&.created_at)
   end
 
+  private
+
+  def set_tag
+    self.tag = Tag.find_or_create_by_names(@name)&.first
+  end
+
   def reset_data
     self.statuses_count = account.statuses.where(visibility: %i(public unlisted)).tagged_with(tag).count
     self.last_status_at = account.statuses.where(visibility: %i(public unlisted)).tagged_with(tag).select(:created_at).first&.created_at
   end
 
-  private
-
   def validate_featured_tags_limit
     errors.add(:base, I18n.t('featured_tags.errors.limit')) if account.featured_tags.count >= 10
   end
+
+  def validate_tag_name
+    errors.add(:name, :blank) if @name.blank?
+    errors.add(:name, :invalid) unless @name.match?(/\A(#{Tag::HASHTAG_NAME_RE})\z/i)
+  end
 end
diff --git a/app/models/tag.rb b/app/models/tag.rb
index a64042614..f078007f2 100644
--- a/app/models/tag.rb
+++ b/app/models/tag.rb
@@ -15,6 +15,7 @@
 #  last_status_at      :datetime
 #  max_score           :float
 #  max_score_at        :datetime
+#  display_name        :string
 #
 
 class Tag < ApplicationRecord
@@ -24,11 +25,12 @@ class Tag < ApplicationRecord
   has_many :featured_tags, dependent: :destroy, inverse_of: :tag
 
   HASHTAG_SEPARATORS = "_\u00B7\u200c"
-  HASHTAG_NAME_RE    = "([[:word:]_][[:word:]#{HASHTAG_SEPARATORS}]*[[:alpha:]#{HASHTAG_SEPARATORS}][[:word:]#{HASHTAG_SEPARATORS}]*[[:word:]_])|([[:word:]_]*[[:alpha:]][[:word:]_]*)"
+  HASHTAG_NAME_RE    = "([[:alnum:]_][[:alnum:]#{HASHTAG_SEPARATORS}]*[[:alpha:]#{HASHTAG_SEPARATORS}][[:alnum:]#{HASHTAG_SEPARATORS}]*[[:alnum:]_])|([[:alnum:]_]*[[:alpha:]][[:alnum:]_]*)"
   HASHTAG_RE         = /(?:^|[^\/\)\w])#(#{HASHTAG_NAME_RE})/i
 
   validates :name, presence: true, format: { with: /\A(#{HASHTAG_NAME_RE})\z/i }
   validate :validate_name_change, if: -> { !new_record? && name_changed? }
+  validate :validate_display_name_change, if: -> { !new_record? && display_name_changed? }
 
   scope :reviewed, -> { where.not(reviewed_at: nil) }
   scope :unreviewed, -> { where(reviewed_at: nil) }
@@ -46,6 +48,10 @@ class Tag < ApplicationRecord
     name
   end
 
+  def display_name
+    attributes['display_name'] || name
+  end
+
   def usable
     boolean_with_default('usable', true)
   end
@@ -90,8 +96,10 @@ class Tag < ApplicationRecord
 
   class << self
     def find_or_create_by_names(name_or_names)
-      Array(name_or_names).map(&method(:normalize)).uniq { |str| str.mb_chars.downcase.to_s }.map do |normalized_name|
-        tag = matching_name(normalized_name).first || create(name: normalized_name)
+      names = Array(name_or_names).map { |str| [normalize(str), str] }.uniq(&:first)
+
+      names.map do |(normalized_name, display_name)|
+        tag = matching_name(normalized_name).first || create(name: normalized_name, display_name: display_name)
 
         yield tag if block_given?
 
@@ -129,7 +137,7 @@ class Tag < ApplicationRecord
     end
 
     def normalize(str)
-      str.gsub(/\A#/, '')
+      HashtagNormalizer.new.normalize(str)
     end
   end
 
@@ -138,4 +146,8 @@ class Tag < ApplicationRecord
   def validate_name_change
     errors.add(:name, I18n.t('tags.does_not_match_previous_name')) unless name_was.mb_chars.casecmp(name.mb_chars).zero?
   end
+
+  def validate_display_name_change
+    errors.add(:display_name, I18n.t('tags.does_not_match_previous_name')) unless HashtagNormalizer.new.normalize(display_name).casecmp(name.mb_chars).zero?
+  end
 end