PostSetPresenters::Post#related_posts: clean up metatag parsing (#2894).

* Fix `#related_tags` to use `Tag.has_metatag?`.
* Fix Tag::SUBQUERY_METATAGS and Tag::METATAGS to be arrays instead of regexes.

app/javascript/src/javascripts/autocomplete.js.erb

@@ -8,7 +8,7 @@ Autocomplete.TAG_CATEGORIES = <%= TagCategory.mapping.to_json.html_safe %>;
 
 Autocomplete.TAG_PREFIXES = "-|~|" + Object.keys(Autocomplete.TAG_CATEGORIES).map(category => category + ":").join("|");
 Autocomplete.TAG_PREFIXES_REGEX = new RegExp("^(" + Autocomplete.TAG_PREFIXES + ")(.*)$", "i");
-Autocomplete.METATAGS_REGEX = new RegExp("^(" + Autocomplete.METATAGS + "):(.*)$", "i");
+Autocomplete.METATAGS_REGEX = new RegExp("^(" + Autocomplete.METATAGS.join("|") + "):(.*)$", "i");
 
 Autocomplete.initialize_all = function() {
   if (Utility.meta("enable-auto-complete") === "true") {

app/logical/tag_name_validator.rb

@@ -21,7 +21,7 @@ class TagNameValidator < ActiveModel::EachValidator
       record.errors[attribute] << "'#{value}' cannot contain non-printable characters"
     when /[^[[:ascii:]]]/
       record.errors[attribute] << "'#{value}' must consist of only ASCII characters"
-    when /\A(#{Tag::METATAGS}|#{Tag::SUBQUERY_METATAGS}):(.+)\z/i
+    when /\A(#{Regexp.union(Tag::METATAGS)}):(.+)\z/i
       record.errors[attribute] << "'#{value}' cannot begin with '#{$1}:'"
     when /\A(#{Tag.categories.regexp}):(.+)\z/i
       record.errors[attribute] << "'#{value}' cannot begin with '#{$1}:'"

app/models/tag.rb

@@ -1,8 +1,16 @@
 class Tag < ApplicationRecord
   COSINE_SIMILARITY_RELATED_TAG_THRESHOLD = 300
-  METATAGS = "-user|user|-approver|approver|commenter|comm|noter|noteupdater|artcomm|-pool|pool|ordpool|-favgroup|favgroup|-fav|fav|ordfav|md5|-rating|rating|-locked|locked|width|height|mpixels|ratio|score|favcount|filesize|source|-source|id|-id|date|age|order|limit|-status|status|tagcount|parent|-parent|child|pixiv_id|pixiv|search|upvote|downvote|filetype|-filetype|flagger|-flagger|appealer|-appealer|disapproval|-disapproval|" +
+  METATAGS = %w[
-    TagCategory.short_name_list.map {|x| "#{x}tags"}.join("|")
+    -user user -approver approver commenter comm noter noteupdater artcomm
-  SUBQUERY_METATAGS = "commenter|comm|noter|noteupdater|artcomm|flagger|-flagger|appealer|-appealer"
+    -pool pool ordpool -favgroup favgroup -fav fav ordfav md5 -rating rating
+    -locked locked width height mpixels ratio score favcount filesize source
+    -source id -id date age order limit -status status tagcount parent -parent
+    child pixiv_id pixiv search upvote downvote filetype -filetype flagger
+    -flagger appealer -appealer disapproval -disapproval
+  ] + TagCategory.short_name_list.map {|x| "#{x}tags"}
+
+  SUBQUERY_METATAGS = %w[commenter comm noter noteupdater artcomm flagger -flagger appealer -appealer]
+
   has_one :wiki_page, :foreign_key => "title", :primary_key => "name"
   has_one :artist, :foreign_key => "name", :primary_key => "name"
   has_one :antecedent_alias, -> {active}, :class_name => "TagAlias", :foreign_key => "antecedent_name", :primary_key => "name"
@@ -430,7 +438,7 @@ class Tag < ApplicationRecord
     end
 
     def is_metatag?(tag)
-      !!(tag =~ /\A(#{METATAGS}):(.+)\Z/i)
+      tag.match?(/\A(#{Regexp.union(METATAGS)}):(.+)\z/i)
     end
 
     def is_negated_tag?(tag)
@@ -466,7 +474,7 @@ class Tag < ApplicationRecord
       scan_query(query).each do |token|
         q[:tag_count] += 1 unless Danbooru.config.is_unlimited_tag?(token)
 
-        if token =~ /\A(#{METATAGS}):(.+)\Z/i
+        if token =~ /\A(#{Regexp.union(METATAGS)}):(.+)\z/i
           g1 = $1.downcase
           g2 = $2
           case g1

app/presenters/post_set_presenters/post.rb

@@ -24,7 +24,7 @@ module PostSetPresenters
         related_tags_for_single(post_set.tag_string)
       elsif post_set.unordered_tag_array.size == 1
         related_tags_for_single(post_set.unordered_tag_array.first)
-      elsif post_set.tag_string =~ /(?:^|\s)(?:#{Tag::SUBQUERY_METATAGS}):\S+/
+      elsif Tag.has_metatag?(post_set.tag_array, *Tag::SUBQUERY_METATAGS)
         calculate_related_tags_from_post_set
       elsif post_set.is_empty_tag?
         popular_tags

test/unit/tag_test.rb

@@ -242,8 +242,8 @@ class TagTest < ActiveSupport::TestCase
       should_not allow_value("café").for(:name).on(:create)
       should_not allow_value("東方").for(:name).on(:create)
 
-      metatags = Tag::METATAGS.split("|") + Tag::SUBQUERY_METATAGS.split("|") + TagCategory.mapping.keys
+      metatags = Tag::METATAGS + TagCategory.mapping.keys
-      metatags.split("|").each do |metatag|
+      metatags.each do |metatag|
         should_not allow_value("#{metatag}:foo").for(:name).on(:create)
       end
     end