Clear all 2FA-related fields when user disables the feature

app/controllers/profiles/two_factor_auths_controller.rb

@@ -28,8 +28,13 @@ class Profiles::TwoFactorAuthsController < Profiles::ApplicationController
   end
 
   def destroy
-    current_user.otp_required_for_login = false
-    current_user.save!
+    current_user.update_attributes({
+      otp_required_for_login:    false,
+      encrypted_otp_secret:      nil,
+      encrypted_otp_secret_iv:   nil,
+      encrypted_otp_secret_salt: nil,
+      otp_backup_codes:          nil
+    })
 
     redirect_to profile_account_path
   end

spec/controllers/profiles/two_factor_auths_controller_spec.rb

+require 'spec_helper'
+
+describe Profiles::TwoFactorAuthsController do
+  before do
+    # `user` should be defined within the action-specific describe blocks
+    sign_in(user)
+
+    allow(subject).to receive(:current_user).and_return(user)
+  end
+
+  describe 'GET new' do
+    let(:user) { create(:user) }
+
+    it 'generates otp_secret' do
+      expect { get :new }.to change { user.otp_secret }
+    end
+
+    it 'assigns qr_code' do
+      code = double('qr code')
+      expect(subject).to receive(:build_qr_code).and_return(code)
+
+      get :new
+      expect(assigns[:qr_code]).to eq code
+    end
+  end
+
+  describe 'POST create' do
+    let(:user) { create(:user) }
+    let(:pin)  { 'pin-code' }
+
+    def go
+      post :create, pin_code: pin
+    end
+
+    context 'with valid pin' do
+      before do
+        expect(user).to receive(:valid_otp?).with(pin).and_return(true)
+      end
+
+      it 'sets otp_required_for_login' do
+        go
+
+        user.reload
+        expect(user.otp_required_for_login).to eq true
+      end
+
+      it 'presents plaintext codes for the user to save' do
+        expect(user).to receive(:generate_otp_backup_codes!).and_return(%w(a b c))
+
+        go
+
+        expect(assigns[:codes]).to match_array %w(a b c)
+      end
+
+      it 'renders create' do
+        go
+        expect(response).to render_template(:create)
+      end
+    end
+
+    context 'with invalid pin' do
+      before do
+        expect(user).to receive(:valid_otp?).with(pin).and_return(false)
+      end
+
+      it 'assigns error' do
+        go
+        expect(assigns[:error]).to eq 'Invalid pin code'
+      end
+
+      it 'assigns qr_code' do
+        code = double('qr code')
+        expect(subject).to receive(:build_qr_code).and_return(code)
+
+        go
+        expect(assigns[:qr_code]).to eq code
+      end
+
+      it 'renders new' do
+        go
+        expect(response).to render_template(:new)
+      end
+    end
+  end
+
+  describe 'POST codes' do
+    let(:user) { create(:user, :two_factor) }
+
+    it 'presents plaintext codes for the user to save' do
+      expect(user).to receive(:generate_otp_backup_codes!).and_return(%w(a b c))
+
+      post :codes
+      expect(assigns[:codes]).to match_array %w(a b c)
+    end
+
+    it 'persists the generated codes' do
+      post :codes
+
+      user.reload
+      expect(user.otp_backup_codes).not_to be_empty
+    end
+  end
+
+  describe 'DELETE destroy' do
+    let(:user)   { create(:user, :two_factor) }
+    let!(:codes) { user.generate_otp_backup_codes! }
+
+    it 'clears all 2FA-related fields' do
+      expect(user.otp_required_for_login).to eq true
+      expect(user.otp_backup_codes).not_to be_nil
+      expect(user.encrypted_otp_secret).not_to be_nil
+
+      delete :destroy
+
+      expect(user.otp_required_for_login).to eq false
+      expect(user.otp_backup_codes).to be_nil
+      expect(user.encrypted_otp_secret).to be_nil
+    end
+
+    it 'redirects to profile_account_path' do
+      delete :destroy
+
+      expect(response).to redirect_to(profile_account_path)
+    end
+  end
+end