From 6ac0e9cd2f88ee332cf4f0f66f5672a714379879 Mon Sep 17 00:00:00 2001
From: Mike Angell <mike.angell@shopify.com>
Date: Thu, 19 Sep 2019 20:58:57 +1000
Subject: [PATCH] Add frozen test to static registers

---
 test/unit/static_registers_unit_test.rb | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/test/unit/static_registers_unit_test.rb b/test/unit/static_registers_unit_test.rb
index 86aedbf..125440f 100644
--- a/test/unit/static_registers_unit_test.rb
+++ b/test/unit/static_registers_unit_test.rb
@@ -135,6 +135,24 @@ class StaticRegistersUnitTest < Minitest::Test
     assert_equal true, static_register.key?(true)
   end
 
+  def test_static_register_can_be_frozen
+    static_register = set_with_static
+
+    static = static_register.static.freeze
+
+    assert_raises(RuntimeError) do
+      static["two"] = "foo"
+    end
+
+    assert_raises(RuntimeError) do
+      static["unknown"] = "foo"
+    end
+
+    assert_raises(RuntimeError) do
+      static.delete("two")
+    end
+  end
+
   def test_new_static_retains_static
     static_register = StaticRegisters.new(nil => true, 1 => :one, :one => "one", "two" => 3, false => nil)
     static_register["one"] = 1