1 files changed, 33 insertions, 0 deletions
diff --git a/test/prism/magic_comment_test.rb b/test/prism/magic_comment_test.rb
new file mode 100644
index 0000000000..9e2e92af92
--- /dev/null
+++ b/test/prism/magic_comment_test.rb
@@ -0,0 +1,33 @@
+# frozen_string_literal: true
+
+require_relative "test_helper"
+
+return if RUBY_ENGINE != "ruby"
+
+module Prism
+  class MagicCommentTest < TestCase
+    examples = [
+      "# encoding: ascii",
+      "# coding: ascii",
+      "# eNcOdInG: ascii",
+      "# CoDiNg: ascii",
+      "# \s\t\v encoding \s\t\v : \s\t\v ascii \s\t\v",
+      "# -*- encoding: ascii -*-",
+      "# -*- coding: ascii -*-",
+      "# -*- eNcOdInG: ascii -*-",
+      "# -*- CoDiNg: ascii -*-",
+      "# -*- \s\t\v encoding \s\t\v : \s\t\v ascii \s\t\v -*-",
+      "# -*- foo: bar; encoding: ascii -*-",
+      "# coding \t \r  \v   :     \t \v    \r   ascii-8bit",
+      "# vim: filetype=ruby, fileencoding=windows-31j, tabsize=3, shiftwidth=3"
+    ]
+
+    examples.each.with_index(1) do |example, index|
+      define_method(:"test_magic_comment_#{index}") do
+        expected = RubyVM::InstructionSequence.compile(%Q{#{example}\n""}).eval.encoding
+        actual = Prism.parse(example).encoding
+        assert_equal expected, actual
+      end
+    end
+  end
+end