favgroups: add stricter favgroup naming rules.

Don't allow favgroup names that:

* Start or end with underscores.
* Contain multiple underscores in a row.
* Contain asterisks or non-printable characters.
* Consist of only underscores.
* Consist of only digits (conflicts with `favgroup:1234` syntax).

Add a fix script that fixes favgroups that violate these rules and notifies the user.

app/models/favorite_group.rb

@@ -4,12 +4,10 @@ class FavoriteGroup < ApplicationRecord
   belongs_to :creator, class_name: "User"
 
   before_validation :normalize_name
-  before_validation :strip_name
 
   validates :name, presence: true
   validates :name, uniqueness: { case_sensitive: false, scope: :creator_id }
-  validates :name, format: { without: /,/, message: "cannot have commas" }
-  validates :name, exclusion: { in: %w[any none], message: "can't be '%{value}'" }
+  validate :validate_name, if: :name_changed?
   validate :creator_can_create_favorite_groups, :on => :create
   validate :validate_number_of_posts
   validate :validate_posts
@@ -104,8 +102,31 @@ class FavoriteGroup < ApplicationRecord
     end
   end
 
+  def validate_name
+    case name
+    when /\A(any|none)\z/i
+      errors.add(:name, "cannot be '#{name}'")
+    when /,/
+      errors.add(:name, "cannot contain commas")
+    when /\*/
+      errors.add(:name, "cannot contain asterisks")
+    when /\A_/
+      errors.add(:name, "cannot begin with an underscore")
+    when /_\z/
+      errors.add(:name, "cannot end with an underscore")
+    when /__/
+      errors.add(:name, "cannot contain consecutive underscores")
+    when /[^[:graph:]]/
+      errors.add(:name, "cannot contain non-printable characters")
+    when ""
+      errors.add(:name, "cannot be blank")
+    when /\A[0-9]+\z/
+      errors.add(:name, "cannot contain only digits")
+    end
+  end
+
   def self.normalize_name(name)
-    name.gsub(/[[:space:]]+/, "_")
+    name.gsub(/[_[:space:]]+/, "_").gsub(/\A_|_\z/, "")
   end
 
   def normalize_name
@@ -128,10 +149,6 @@ class FavoriteGroup < ApplicationRecord
     find_by_name_or_id(name, user) or raise ActiveRecord::RecordNotFound
   end
 
-  def strip_name
-    self.name = name.to_s.strip
-  end
-
   def pretty_name
     name&.tr("_", " ")
   end

script/fixes/129_fix_favgroup_names.rb

@@ -0,0 +1,66 @@
+#!/usr/bin/env ruby
+
+require_relative "base"
+
+with_confirmation do
+  fix = ENV.fetch("FIX", "false").truthy?
+
+  users = User.where.associated(:favorite_groups).distinct
+  users.find_each do |user|
+    changed_favgroups = []
+
+    user.favorite_groups.each do |favgroup|
+      if favgroup.name.match?(/[^[:graph:]]/)
+        favgroup.name.gsub!(/[^[:graph:]]/, "_")
+      end
+
+      if favgroup.name.include?("*")
+        favgroup.name.tr!("*", "?")
+      end
+
+      if favgroup.name.include?("__")
+        favgroup.name.gsub!(/_+/, "_")
+      end
+
+      if favgroup.name.starts_with?("_")
+        favgroup.name.delete_prefix!("_")
+      end
+
+      if favgroup.name.ends_with?("_")
+        favgroup.name.delete_suffix!("_")
+      end
+
+      if favgroup.name.match?(/\A[0-9]+\z/)
+        favgroup.name = "favgroup_#{favgroup.name}"
+      end
+
+      if favgroup.name.blank? || user.favorite_groups.without(favgroup).exists?(name: favgroup.name)
+        favgroup.name = "favgroup_#{favgroup.id}"
+      end
+
+      if favgroup.changed?
+        changed_favgroups << favgroup
+        puts ({ id: favgroup.id, creator: favgroup.creator.name, changes: favgroup.changes }).to_json
+        favgroup.save! if fix
+      end
+    end
+
+    if fix && changed_favgroups.present?
+      Dmail.create_automated(to: user, title: "Your favorite groups have been renamed", disable_email_notifications: true, body: <<~EOS)
+        The following #{"favgroup".pluralize(changed_favgroups.size)} #{changed_favgroups.one? ? "has" : "have"} been renamed:
+
+        #{changed_favgroups.map { |favgroup| "* favgroup ##{favgroup.id}: \"#{favgroup.name_was}\" -> \"#{favgroup.name}\"" }.join("\n")}
+
+        Your #{"favgroup".pluralize(changed_favgroups.size)} had to be renamed because #{changed_favgroups.one? ? "it" : "they"} didn't follow one of our new naming rules:
+
+        * Names can't consist of numbers only.
+        * Names can't start or end with an underscore (_).
+        * Names can't contain multiple underscores in a row (__).
+        * Names can't contain commas or asterisks (*).
+        * Names can't be blank.
+
+        You can change the name to something else by going to your "Favgroups":[/favorite_groups] page and clicking "Edit" to change the name.
+      EOS
+    end
+  end
+end

test/unit/favorite_group_test.rb

@@ -58,4 +58,15 @@ class FavoriteGroupTest < ActiveSupport::TestCase
       assert_equal([], @fav_group.reload.post_ids)
     end
   end
+
+  context "when validating names" do
+    subject { build(:favorite_group) }
+
+    should_not allow_value("foo,bar").for(:name)
+    should_not allow_value("foo*bar").for(:name)
+    should_not allow_value("123").for(:name)
+    should_not allow_value("_").for(:name)
+    should_not allow_value("any").for(:name)
+    should_not allow_value("none").for(:name)
+  end
 end