diff --git a/tests/test_jasinta.py b/tests/test_jasinta.py
new file mode 100644
--- /dev/null
+++ b/tests/test_jasinta.py
@@ -0,0 +1,22 @@
+from unittest import TestCase
+from unittest.mock import MagicMock
+
+from pyjsparser import parse
+
+from jasinta import interpret
+import std as jasinta_std
+
+
+class TestBasicAddition(TestCase):
+	def setUp(self):
+		self.mock_print = MagicMock()
+		jasinta_std.lib["document"]["write"] = self.mock_print
+
+	def test_interpret(self):
+		s = """var a=3;
+var b=1;
+var c=a+b;
+document.write(c);"""
+
+		interpret(parse(s))
+		self.mock_print.assert_called_with(4.0)