Add test_et_jsonizer.py

Author: TaekyungHeo

tests/test_et_jsonizer.py

@@ -0,0 +1,21 @@
+import pytest
+from chakra.et_jsonizer import main
+from unittest.mock import patch, mock_open
+
+def test_run_with_valid_input():
+    test_args = ["et_jsonizer.py", "--input_filename", "valid_input.et", "--output_filename", "output.json"]
+    with patch('sys.argv', test_args), \
+         patch('chakra.et_jsonizer.open_file_rd') as mock_open_file_rd, \
+         patch('builtins.open', mock_open()):
+        main()  # No assertion needed; we're checking if it runs without error
+
+def test_missing_arguments():
+    with pytest.raises(SystemExit):
+        with patch('sys.argv', ['et_jsonizer.py']):
+            main()
+
+def test_missing_file_path():
+    test_args = ["et_jsonizer.py", "--input_filename", "nonexistent_input.et", "--output_filename", "output.json"]
+    with patch('sys.argv', test_args):
+        with pytest.raises(FileNotFoundError):
+            main()