Add attribute Account#username

app/models/account.rb

@@ -1,6 +1,8 @@
 # frozen_string_literal: true
 
 class Account < ApplicationRecord
+  USERNAME_RE = /\A[a-z][_a-z0-9]*[a-z0-9]\z/i.freeze
+
   rolify role_join_table_name: :account_roles
 
   belongs_to :person, optional: true
@@ -18,10 +20,18 @@ class Account < ApplicationRecord
 
   scope :guests, -> { includes(:user).where(users: { id: nil }) }
 
+  after_initialize :generate_username
+
   before_create do
     self.guest_token = SecureRandom.hex
   end
 
+  validates :username,
+            presence:   true,
+            length:     { in: 3..36 },
+            format:     USERNAME_RE,
+            uniqueness: { case_sensitive: false }
+
   validates :person_id, allow_nil: true, uniqueness: true
 
   def guest?
@@ -37,4 +47,10 @@ class Account < ApplicationRecord
   def can_access_sidekiq_web_interface?
     is_superuser?
   end
+
+private
+
+  def generate_username
+    self.username = "noname_#{SecureRandom.hex(8)}" if username.nil?
+  end
 end

db/migrate/20190201002444_add_username_to_accounts.rb

@@ -0,0 +1,7 @@
+# frozen_string_literal: true
+
+class AddUsernameToAccounts < ActiveRecord::Migration[6.0]
+  def change
+    add_column :accounts, :username, :string, index: { unique: true }
+  end
+end

db/schema.rb

@@ -10,7 +10,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 2019_01_31_025820) do
+ActiveRecord::Schema.define(version: 2019_02_01_002444) do
 
   # These are extensions that must be enabled in order to support this database
   enable_extension "plpgsql"
@@ -39,6 +39,7 @@ ActiveRecord::Schema.define(version: 2019_01_31_025820) do
     t.datetime "updated_at", null: false
     t.string "guest_token", null: false
     t.bigint "person_id"
+    t.string "username"
     t.index ["person_id"], name: "index_accounts_on_person_id", unique: true
   end
 

spec/models/account_spec.rb

@@ -39,6 +39,33 @@ RSpec.describe Account do
   pending '#guest?'
   pending '#can_access_sidekiq_web_interface?'
 
+  describe '#username' do
+    def allow_value(*)
+      super.for :username
+    end
+
+    it { is_expected.to validate_presence_of :username }
+
+    it do
+      is_expected.to validate_length_of(:username).is_at_least(3).is_at_most(36)
+    end
+
+    it { is_expected.to validate_uniqueness_of(:username).case_insensitive }
+
+    it { is_expected.not_to allow_value nil }
+    it { is_expected.not_to allow_value '' }
+    it { is_expected.not_to allow_value ' ' * 3 }
+
+    it { is_expected.to allow_value Faker::Internet.username(3..36, %w[_]) }
+    it { is_expected.to allow_value 'foo_bar' }
+    it { is_expected.to allow_value 'foo123' }
+
+    it { is_expected.not_to allow_value Faker::Internet.email }
+    it { is_expected.not_to allow_value '_foo' }
+    it { is_expected.not_to allow_value 'bar_' }
+    it { is_expected.not_to allow_value '1foo' }
+  end
+
   describe '#add_role' do
     context 'to guest account' do
       subject { create :guest_account }