Extract "@request.env['devise.mapping'] = Devise.mappings[:user]" to a test helper

Extracted `@request.env['devise.mapping'] = Devise.mappings[:user]` and `Rails.application.env_config['devise.mapping'] = Devise.mappings[:user]`
in our tests into the helper method `set_devise_mapping`

changelogs/unreleased/34549-extract-devise-mappings-into-helper.yml

+---
+title: Extract "@request.env[devise.mapping] = Devise.mappings[:user]" to a test helper
+merge_request: 12742
+author: Jacopo Beschi @jacopo-beschi

spec/controllers/sessions_controller_spec.rb

 require 'spec_helper'
 describe SessionsController do
+  include DeviseHelpers
+
   describe '#new' do
     before do
-      @request.env['devise.mapping'] = Devise.mappings[:user]
+      set_devise_mapping(context: @request)
     end
     context 'when auto sign-in is enabled' do
@@ -34,7 +36,7 @@ describe SessionsController do
   describe '#create' do
     before do
-      @request.env['devise.mapping'] = Devise.mappings[:user]
+      set_devise_mapping(context: @request)
     end
     context 'when using standard authentications' do
@@ -257,7 +259,7 @@ describe SessionsController do
   describe '#new' do
     before do
-      @request.env['devise.mapping'] = Devise.mappings[:user]
+      set_devise_mapping(context: @request)
     end
     it 'redirects correctly for referer on same host with params' do

spec/features/oauth_login_spec.rb

 require 'spec_helper'
 feature 'OAuth Login', js: true do
+  include DeviseHelpers
+
   def enter_code(code)
     fill_in 'user_otp_attempt', with: code
     click_button 'Verify code'
@@ -8,7 +10,7 @@ feature 'OAuth Login', js: true do
   def stub_omniauth_config(provider)
     OmniAuth.config.add_mock(provider, OmniAuth::AuthHash.new(provider: provider.to_s, uid: "12345"))
-    Rails.application.env_config['devise.mapping'] = Devise.mappings[:user]
+    set_devise_mapping(context: Rails.application)
     Rails.application.env_config['omniauth.auth'] = OmniAuth.config.mock_auth[provider]
   end

spec/javascripts/fixtures/u2f.rb

@@ -10,10 +10,12 @@ context 'U2F' do
   end
   describe SessionsController, '(JavaScript fixtures)', type: :controller do
+    include DeviseHelpers
+
     render_views
     before do
-      @request.env['devise.mapping'] = Devise.mappings[:user]
+      set_devise_mapping(context: @request)
     end
     it 'u2f/authenticate.html.raw' do |example|

spec/support/devise_helpers.rb

+module DeviseHelpers
+  # explicitly tells Devise which mapping to use
+  # this is needed when we are testing a Devise controller bypassing the router
+  def set_devise_mapping(context:)
+    env =
+      if context.respond_to?(:env_config)
+        context.env_config
+      elsif context.respond_to?(:env)
+        context.env
+      end
+
+    env['devise.mapping'] = Devise.mappings[:user] if env
+  end
+end

spec/support/login_helpers.rb

 module LoginHelpers
+  include DeviseHelpers
+
   # Internal: Log in as a specific user or a new user of a specific role
   #
   # user_or_role - User object, or a role to create (e.g., :admin, :user)
@@ -106,7 +108,7 @@ module LoginHelpers
   end
   def stub_omniauth_saml_config(messages)
-    Rails.application.env_config['devise.mapping'] = Devise.mappings[:user]
+    set_devise_mapping(context: Rails.application)
     Rails.application.routes.disable_clear_and_finalize = true
     Rails.application.routes.draw do
       post '/users/auth/saml' => 'omniauth_callbacks#saml'