1 files changed, 31 insertions, 0 deletions
diff --git a/test/fiddle/test_c_union_entity.rb b/test/fiddle/test_c_union_entity.rb
new file mode 100644
index 0000000000..d27c9edb52
--- /dev/null
+++ b/test/fiddle/test_c_union_entity.rb
@@ -0,0 +1,31 @@
+require_relative 'helper'
+
+require 'fiddle/struct'
+
+module Fiddle
+  class TestCUnionEntity < TestCase
+    def test_class_size
+      size = CUnionEntity.size([TYPE_DOUBLE, TYPE_CHAR])
+
+      assert_equal SIZEOF_DOUBLE, size
+    end
+
+    def test_class_size_with_count
+      size = CUnionEntity.size([[TYPE_DOUBLE, 2], [TYPE_CHAR, 20]])
+
+      assert_equal SIZEOF_CHAR * 20, size
+    end
+
+    def test_set_ctypes
+      union = CUnionEntity.malloc [TYPE_INT, TYPE_LONG]
+      union.assign_names %w[int long]
+
+      # this test is roundabout because the stored ctypes are not accessible
+      union['long'] = 1
+      assert_equal 1, union['long']
+
+      union['int'] = 1
+      assert_equal 1, union['int']
+    end
+  end
+end