refactor: simplify error handling

app/controllers/google/callbacks_controller.rb

@@ -19,7 +19,7 @@ class Google::CallbacksController < OauthCallbackController
     missing_scopes = required_scopes - granted_scopes
     return if missing_scopes.empty?
 
-    raise CustomExceptions::OAuth::InsufficientScopes.new({ missing_scopes: missing_scopes })
+    raise StandardError, I18n.t('errors.oauth.insufficient_scopes', scopes: missing_scopes.join(', '))
   end
 
   def provider_name
@@ -38,10 +38,9 @@ class Google::CallbacksController < OauthCallbackController
   def handle_error(exception)
     ChatwootExceptionTracker.new(exception).capture_exception
 
-    error_code = exception.respond_to?(:code) ? exception.code : 'OAUTH_ERR'
-    error_message = exception.message || I18n.t('errors.oauth.authorization_failed', provider: 'Google')
-
+    error_message = exception.message || I18n.t('errors.oauth.authorization_failed')
     redirect_url = "#{ENV.fetch('FRONTEND_URL', 'http://localhost:3000')}/app/accounts/#{account.id}/settings/inboxes/new/email"
-    redirect_to "#{redirect_url}?error=#{CGI.escape(error_message)}&code=#{error_code}"
+
+    redirect_to "#{redirect_url}?error=#{CGI.escape(error_message)}"
   end
 end

config/locales/en.yml

@@ -50,7 +50,7 @@ en:
       failed: Signup failed
     oauth:
       insufficient_scopes: 'Insufficient permissions granted. Missing scopes: %{scopes}'
-      authorization_failed: 'Authorization failed for %{provider}'
+      authorization_failed: 'Authorization failed'
     data_import:
       data_type:
         invalid: Invalid data type

lib/custom_exceptions/oauth.rb

@@ -1,21 +0,0 @@
-# frozen_string_literal: true
-
-module CustomExceptions::OAuth
-  class InsufficientScopes < CustomExceptions::Base
-    def message
-      I18n.t('errors.oauth.insufficient_scopes', scopes: @data[:missing_scopes].join(', '))
-    end
-
-    def code
-      'SCOPE_ERR'
-    end
-
-    def to_hash
-      {
-        message: message,
-        code: code,
-        missing_scopes: @data[:missing_scopes]
-      }
-    end
-  end
-end

spec/controllers/google/callbacks_controller_spec.rb

@@ -73,7 +73,20 @@ RSpec.describe 'Google::CallbacksController', type: :request do
       expect(inbox.name).to eq email.split('@').first.parameterize.titleize
     end
 
-    it 'redirects to google app in case of error' do
+    it 'redirects to custom error URL when insufficient scopes are granted' do
+      stub_request(:post, 'https://accounts.google.com/o/oauth2/token')
+        .with(body: { 'code' => code, 'grant_type' => 'authorization_code',
+                      'redirect_uri' => "#{ENV.fetch('FRONTEND_URL', 'http://localhost:3000')}/google/callback" })
+        .to_return(status: 200, body: response_body_insufficient_scopes.to_json, headers: { 'Content-Type' => 'application/json' })
+
+      get google_callback_url, params: { code: code }
+
+      expect(response).to redirect_to(/#{Regexp.escape("#{ENV.fetch('FRONTEND_URL', 'http://localhost:3000')}/app/accounts/#{account.id}/settings/inboxes/new/email")}/)
+      expect(response.location).to include('error=')
+      expect(Redis::Alfred.get(cache_key).to_i).to eq account.id
+    end
+
+    it 'redirects to custom error URL in case of OAuth error' do
       stub_request(:post, 'https://accounts.google.com/o/oauth2/token')
         .with(body: { 'code' => code, 'grant_type' => 'authorization_code',
                       'redirect_uri' => "#{ENV.fetch('FRONTEND_URL', 'http://localhost:3000')}/google/callback" })
@@ -81,7 +94,8 @@ RSpec.describe 'Google::CallbacksController', type: :request do
 
       get google_callback_url, params: { code: code }
 
-      expect(response).to redirect_to '/'
+      expect(response).to redirect_to(/#{Regexp.escape("#{ENV.fetch('FRONTEND_URL', 'http://localhost:3000')}/app/accounts/#{account.id}/settings/inboxes/new/email")}/)
+      expect(response.location).to include('error=')
       expect(Redis::Alfred.get(cache_key).to_i).to eq account.id
     end
   end