test: cover I18nBackendTest, test_lookup_returns_nil_for_unknown_key

test/test_i18n_backend.rb

@@ -0,0 +1,53 @@
+require 'minitest/autorun'
+require 'prism'
+require 'tmpdir'
+
+class I18nBackendTest < Minitest::Test
+  def setup
+    @backend = Prism::I18n::Backend.new
+  end
+
+  def test_lookup_returns_nil_for_unknown_key
+    assert_nil @backend.lookup(:en, 'missing.key')
+  end
+
+  def test_store_and_lookup_nested_key
+    @backend.store_translations(:en, 'posts' => { 'title' => 'Title', 'body' => 'Body' })
+    assert_equal 'Title', @backend.lookup(:en, 'posts.title')
+    assert_equal 'Body', @backend.lookup(:en, :'posts.body')
+  end
+
+  def test_store_translations_deep_merges_instead_of_replacing
+    @backend.store_translations(:en, 'posts' => { 'title' => 'Title' })
+    @backend.store_translations(:en, 'posts' => { 'body' => 'Body' })
+    assert_equal 'Title', @backend.lookup(:en, 'posts.title')
+    assert_equal 'Body', @backend.lookup(:en, 'posts.body')
+  end
+
+  def test_locales_lists_every_stored_locale
+    @backend.store_translations(:en, 'hello' => 'Hello')
+    @backend.store_translations(:pl, 'hello' => 'Czesc')
+    assert_equal [:en, :pl], @backend.locales.sort
+  end
+
+  def test_lookup_returns_nil_when_key_path_hits_a_non_hash
+    @backend.store_translations(:en, 'hello' => 'Hello')
+    assert_nil @backend.lookup(:en, 'hello.nested')
+  end
+
+  def test_load_file_reads_json_and_uses_basename_as_locale
+    Dir.mktmpdir do |dir|
+      path = File.join(dir, 'en.json')
+      File.write(path, '{"greeting": "Hi %{name}"}')
+      locale = @backend.load_file(path)
+      assert_equal :en, locale
+      assert_equal 'Hi %{name}', @backend.lookup(:en, 'greeting')
+    end
+  end
+
+  def test_clear_removes_all_translations
+    @backend.store_translations(:en, 'hello' => 'Hello')
+    @backend.clear!
+    assert_empty @backend.locales
+  end
+end