extract method #populate_otp_column

useful for populating column values for pre-existing devise-enabled records

lib/two_factor_authentication/models/two_factor_authenticatable.rb

@@ -12,7 +12,7 @@ def has_one_time_password(options = {})
 
           include InstanceMethodsOnActivation
 
-          before_create { self.otp_column = ROTP::Base32.random_base32 }
+          before_create { populate_otp_column }
 
           if respond_to?(:attributes_protected_by_default)
             def self.attributes_protected_by_default #:nodoc:
@@ -60,6 +60,10 @@ def max_login_attempts?
           second_factor_attempts_count >= self.class.max_login_attempts
         end
 
+        def populate_otp_column
+          self.otp_column = ROTP::Base32.random_base32
+        end
+
       end
     end
   end

spec/lib/two_factor_authentication/models/two_factor_authenticatable_spec.rb

@@ -1,7 +1,6 @@
 require 'spec_helper'
 include AuthenticatedModelHelper
 
-
 describe Devise::Models::TwoFactorAuthenticatable, '#otp_code' do
   let(:instance) { AuthenticatedModelHelper.create_new_user }
   subject { instance.otp_code(time) }
@@ -67,4 +66,26 @@ def do_invoke code, options = {}
     instance = AuthenticatedModelHelper.create_new_user_with_overrides
     expect(instance.send_two_factor_authentication_code).to eq("Code sent")
   end
-end
+end
+
+describe Devise::Models::TwoFactorAuthenticatable, '#populate_otp_column' do
+  let(:instance) { AuthenticatedModelHelper.create_new_user }
+
+  it "populates otp_column on create" do
+    expect(instance.otp_secret_key).to be_nil
+
+    instance.run_callbacks :create # populate_otp_column called via before_create
+
+    expect(instance.otp_secret_key).to match(%r{\w{16}})
+  end
+
+  it "repopulates otp_column" do
+    instance.run_callbacks :create
+    original_key = instance.otp_secret_key
+
+    instance.populate_otp_column
+
+    expect(instance.otp_secret_key).to match(%r{\w{16}})
+    expect(instance.otp_secret_key).to_not eq(original_key)
+  end
+end