From 94f5c714f11248df6a2b793f47cdb30028f67fca Mon Sep 17 00:00:00 2001
From: Rey Tucker <git@reytucker.us>
Date: Wed, 24 Jul 2019 08:19:17 -0400
Subject: [PATCH]  Don't delete periods when validating username uniqueness
 (#11392) (#11400)

* Check to make sure usernames with '.' cannot be created

* Add test for instance actor account name conflicts

This makes sure that migration 20190715164535_add_instance_actor
won't fail if there's already an account that is named the same
as the domain (minus the .)

* Put the test into the correct context...

* Add another test to split this into two validations

* Don't delete periods when validating username uniqueness (#11392)

The 20190715164535_add_instance_actor migration fails if there's
already a username similar to the domain name, e.g. if you are
'vulpine.club' and have a user named 'vulpineclub', validation
fails.

Upon further review, usernames with periods are dropped by the
regular expression in the Account class, so we don't need to
worry about it here.

Fixes #11392
---
 app/validators/unique_username_validator.rb |  4 +++-
 spec/models/account_spec.rb                 | 17 +++++++++++++++++
 2 files changed, 20 insertions(+), 1 deletion(-)

diff --git a/app/validators/unique_username_validator.rb b/app/validators/unique_username_validator.rb
index fb67105dd6..4e24e3f5fe 100644
--- a/app/validators/unique_username_validator.rb
+++ b/app/validators/unique_username_validator.rb
@@ -1,10 +1,12 @@
 # frozen_string_literal: true
 
+# See also: USERNAME_RE in the Account class
+
 class UniqueUsernameValidator < ActiveModel::Validator
   def validate(account)
     return if account.username.nil?
 
-    normalized_username = account.username.downcase.delete('.')
+    normalized_username = account.username.downcase
 
     scope = Account.where(domain: nil).where('lower(username) = ?', normalized_username)
     scope = scope.where.not(id: account.id) if account.persisted?
diff --git a/spec/models/account_spec.rb b/spec/models/account_spec.rb
index 6495a61934..3a17d540ac 100644
--- a/spec/models/account_spec.rb
+++ b/spec/models/account_spec.rb
@@ -583,12 +583,29 @@ RSpec.describe Account, type: :model do
         expect(account.valid?).to be true
       end
 
+      it 'is valid if we are creating an instance actor account with a period' do
+        account = Fabricate.build(:account, id: -99, actor_type: 'Application', locked: true, username: 'example.com')
+        expect(account.valid?).to be true
+      end
+
+      it 'is valid if we are creating a possibly-conflicting instance actor account' do
+        account_1 = Fabricate(:account, username: 'examplecom')
+        account_2 = Fabricate.build(:account, id: -99, actor_type: 'Application', locked: true, username: 'example.com')
+        expect(account_2.valid?).to be true
+      end
+
       it 'is invalid if the username doesn\'t only contains letters, numbers and underscores' do
         account = Fabricate.build(:account, username: 'the-doctor')
         account.valid?
         expect(account).to model_have_error_on_field(:username)
       end
 
+      it 'is invalid if the username contains a period' do
+        account = Fabricate.build(:account, username: 'the.doctor')
+        account.valid?
+        expect(account).to model_have_error_on_field(:username)
+      end
+
       it 'is invalid if the username is longer then 30 characters' do
         account = Fabricate.build(:account, username: Faker::Lorem.characters(31))
         account.valid?