Refactor & fix sign up constraints

app/helpers/database_helper.rb

@@ -1,5 +1,4 @@
 module DatabaseHelper
-
   # Check if database adapter equals to the specified name
   def db_adapter_is?(adapter_name)
     ActiveRecord::Base.connection.adapter_name == adapter_name
@@ -22,7 +21,7 @@ module DatabaseHelper
   # Create gist trigram index. PostgreSQL only!
   def add_gist_index(table, column)
     ActiveRecord::Base.connection.execute(
-      "CREATE INDEX index_#{table}_on_#{column} ON " +
+      "CREATE INDEX index_#{table}_on_#{column} ON " \
       "#{table} USING gist (#{column} gist_trgm_ops);"
     )
   end
@@ -49,21 +48,30 @@ module DatabaseHelper
   # in table for specific id. PostgreSQL only!
   def get_octet_length(table, column, id)
     ActiveRecord::Base.connection.execute(
-      "SELECT octet_length(cast(t.#{column} as text)) FROM #{table} " +
+      "SELECT octet_length(cast(t.#{column} as text)) FROM #{table} " \
       "AS t WHERE t.id = #{id};"
     ).getvalue(0, 0).to_i
   end
 
-  # Adds email domain constraint to the users table.
-  def add_email_constraint(domain)
+  # Adds a check constraint to the table
+  def add_check_constraint(table, constraint_name, constraint)
     ActiveRecord::Base.connection.execute(
       "ALTER TABLE " \
-         "users " \
-      "DROP CONSTRAINT IF EXISTS email_must_be_company_email, " \
+      "#{table} " \
+      "DROP CONSTRAINT IF EXISTS #{constraint_name}, " \
       "ADD CONSTRAINT " \
-        "email_must_be_company_email " \
-      "CHECK ( email ~* '^[A-Za-z0-9._%-]+@#{domain}' ) " \
+      "#{constraint_name} " \
+      "CHECK ( #{constraint} ) " \
       "not valid;"
     )
   end
+
+  # Remove constraint from the table
+  def drop_constraint(table, constraint_name)
+    ActiveRecord::Base.connection.execute(
+      "ALTER TABLE " \
+      "#{table} " \
+      "DROP CONSTRAINT IF EXISTS #{constraint_name}; "
+    )
+  end
 end

lib/tasks/sign_up_constraint.rake

@@ -14,17 +14,19 @@ namespace :sign_up_constraint do
     domain = args[:domain]
     domain = domain.strip.gsub(/\./, '\\.')
 
-    add_email_constraint(domain)
+    add_check_constraint(
+      'users',
+      'email_must_be_company_email',
+      "email ~* '^[A-Za-z0-9._%-+]+@#{domain}'"
+    )
     puts "Created the following domain constraint: #{args[:domain]}"
   end
 
   desc 'Remove email domain constraint from the users table.'
   task remove_domain: :environment do
-    ActiveRecord::Base.connection.execute(
-      'ALTER TABLE ' \
-         'users ' \
-      'DROP CONSTRAINT IF EXISTS email_must_be_company_email; '
-    )
+    include DatabaseHelper
+
+    drop_constraint('users', 'email_must_be_company_email')
     puts 'Email constraint has been removed'
   end
 end