Add support for invite codes in the registration API (#27805)

spec/requests/invite_spec.rb

@@ -0,0 +1,27 @@
+# frozen_string_literal: true
+
+require 'rails_helper'
+
+describe 'invites' do
+  let(:invite) { Fabricate(:invite) }
+
+  context 'when requesting a JSON document' do
+    it 'returns a JSON document with expected attributes' do
+      get "/invite/#{invite.code}", headers: { 'Accept' => 'application/activity+json' }
+
+      expect(response).to have_http_status(200)
+      expect(response.media_type).to eq 'application/json'
+
+      expect(body_as_json[:invite_code]).to eq invite.code
+    end
+  end
+
+  context 'when not requesting a JSON document' do
+    it 'returns an HTML page' do
+      get "/invite/#{invite.code}"
+
+      expect(response).to have_http_status(200)
+      expect(response.media_type).to eq 'text/html'
+    end
+  end
+end