test: cover I18nBackendTest, test_lookup_returns_nil_for_unknown_key

test/test_i18n_controller.rb

@@ -0,0 +1,85 @@
+require 'minitest/autorun'
+require 'prism'
+require 'support'
+
+class GreetingsController < Prism::Controller
+  def show
+    html(t('hello'))
+  end
+
+  def remember
+    session[:locale] = params['locale']
+    html(t('hello'))
+  end
+
+  def stamp
+    html(l(Time.utc(2026, 3, 5, 8, 30, 0)))
+  end
+end
+
+class GreetingsApp < Prism::Application
+  enable_sessions secret: 'i18n-controller-test-secret'
+
+  get '/greet', to: 'greetings#show'
+  get '/greet/remember', to: 'greetings#remember'
+  get '/greet/stamp', to: 'greetings#stamp'
+end
+
+class I18nControllerTest < Minitest::Test
+  include TestSupport
+
+  def setup
+    Prism::I18n.reset!
+    Prism::I18n.store_translations(:en, 'hello' => 'Hello')
+    Prism::I18n.store_translations(:pl, 'hello' => 'Czesc')
+  end
+
+  def teardown
+    Prism::I18n.reset!
+  end
+
+  def call(method, path, **opts)
+    GreetingsApp.call(env_for(method, path, **opts))
+  end
+
+  def test_defaults_to_default_locale_with_no_hints
+    _, _, body = call('GET', '/greet')
+    assert_equal 'Hello', body.join
+  end
+
+  def test_locale_query_param_overrides_default
+    _, _, body = call('GET', '/greet?locale=pl')
+    assert_equal 'Czesc', body.join
+  end
+
+  def test_unknown_locale_query_param_is_ignored
+    _, _, body = call('GET', '/greet?locale=de')
+    assert_equal 'Hello', body.join
+  end
+
+  def test_accept_language_header_is_used_when_no_param_given
+    _, _, body = call('GET', '/greet', headers: { 'Accept-Language' => 'pl,en;q=0.5' })
+    assert_equal 'Czesc', body.join
+  end
+
+  def test_locale_param_wins_over_accept_language_header
+    _, _, body = call('GET', '/greet?locale=en', headers: { 'Accept-Language' => 'pl' })
+    assert_equal 'Hello', body.join
+  end
+
+  def test_session_locale_is_sticky_across_requests
+    status, headers, body = call('GET', '/greet/remember?locale=pl')
+    assert_equal 200, status
+    assert_equal 'Czesc', body.join
+    line = headers['Set-Cookie'].split("\n").find { |c| c.start_with?('prism.session=') }
+    cookie = line.split(';').first
+
+    _, _, body = call('GET', '/greet', cookies: cookie)
+    assert_equal 'Czesc', body.join
+  end
+
+  def test_localize_helper_formats_time_in_view
+    _, _, body = call('GET', '/greet/stamp')
+    assert_equal '2026-03-05 08:30:00', body.join
+  end
+end