Fix broken OmniAuth login

Gemfile

@@ -52,6 +52,7 @@ gem 'will_paginate-bootstrap4', '~> 0.2.2'
 
 gem 'devise', '~> 4.8.0'
 gem 'omniauth'
+gem 'omniauth-rails_csrf_protection'
 gem 'omniauth-github'
 
 # Use ActiveModel has_secure_password

Gemfile.lock

@@ -160,6 +160,9 @@ GEM
     omniauth-oauth2 (1.7.1)
       oauth2 (~> 1.4)
       omniauth (>= 1.9, < 3)
+    omniauth-rails_csrf_protection (1.0.0)
+      actionpack (>= 4.2)
+      omniauth (~> 2.0)
     orm_adapter (0.5.0)
     popper_js (1.16.0)
     public_suffix (4.0.6)
@@ -278,6 +281,7 @@ DEPENDENCIES
   mysql2 (~> 0.5.2)
   omniauth
   omniauth-github
+  omniauth-rails_csrf_protection
   puma (~> 5.0)
   rails (= 6.1.3.2)
   rails-controller-testing

app/views/layouts/_header.html.erb

@@ -32,9 +32,9 @@
           <% else %>
             <li class="nav-item">
               <% if Rails.env.development? %>
-                <%= link_to t('application.sign_in_with_github'), user_developer_omniauth_authorize_path, class: 'nav-link' %>
+                <%= link_to t('application.sign_in_with_github'), user_developer_omniauth_authorize_path, method: :post, class: 'nav-link' %>
               <% else %>
-                <%= link_to t('application.sign_in_with_github'), user_github_omniauth_authorize_path, class: 'nav-link' %>
+                <%= link_to t('application.sign_in_with_github'), user_github_omniauth_authorize_path, method: :post, class: 'nav-link' %>
               <% end %>
             </li>
           <% end %>

test/integration/translator_flow_test.rb

@@ -8,7 +8,7 @@ class TranslatorFlowTest < ActionDispatch::IntegrationTest
   end
 
   test "can login via github" do
-    get '/users/auth/github'
+    post '/users/auth/github'
     assert_response :redirect
     follow_redirect!
     follow_redirect!