Prevent using # in the stored tag name

app/controllers/taggings/toggles_controller.rb

@@ -3,7 +3,8 @@ class Taggings::TogglesController < ApplicationController
 
   def create
     if params[:tag_title].present?
-      @bubble.toggle_tag Current.account.tags.create!(title: params[:tag_title])
+      sanitized_title = params[:tag_title].strip.gsub(/\A#/, "")
+      @bubble.toggle_tag Current.account.tags.create!(title: sanitized_title)
     else
       new_tag_ids = Array(params[:tag_id])
       current_tags = @bubble.tags

app/models/tag.rb

@@ -6,6 +6,8 @@ class Tag < ApplicationRecord
   has_many :taggings, dependent: :destroy
   has_many :bubbles, through: :taggings
 
+  validates :title, format: { without: /\A#/ }
+
   def hashtag
     "#" + title
   end