Add cli options to output lookml

lkml/__init__.py

@@ -96,6 +96,20 @@ def parse_args(args: Sequence) -> argparse.Namespace:
         help="increase logging verbosity to debug",
     )
 
+    group = parser.add_mutually_exclusive_group()
+    group.add_argument(
+        "--json",
+        action="store_true",
+        default=True,
+        help="return a JSON string (default)",
+    )
+    group.add_argument(
+        "--lookml",
+        action="store_true",
+        default=False,
+        help="return a LookML string",
+    )
+
     return parser.parse_args(args)
 
 
@@ -116,8 +130,15 @@ def cli():
 
     logging.getLogger().setLevel(args.log_level)
 
-    result: dict = load(args.file)
-    args.file.close()
+    try:
+        result: dict = load(args.file)
+
+        if args.lookml:
+            lookml_string = dump(result)
+            print(lookml_string)
+        elif args.json:
+            json_string = json.dumps(result, indent=2)
+            print(json_string)
 
-    json_string = json.dumps(result, indent=2)
-    print(json_string)
+    finally:
+        args.file.close()

tests/test_cli.py

@@ -1,10 +1,11 @@
 import io
-from lkml.tree import ContainerNode, DocumentNode, PairNode, SyntaxToken
-from pathlib import Path
-from unittest.mock import patch
 import logging
 import pytest
 import lkml
+import json
+
+from pathlib import Path
+from unittest.mock import patch
 
 
 @pytest.fixture
@@ -25,15 +26,45 @@ def test_absence_of_debug_flag_is_parsed_to_log_level_warn(lookml_path):
     assert args.log_level == logging.WARN
 
 
-@patch("lkml.load")
-@patch("lkml.parse_args")
-def test_run_cli(mock_parse_args, mock_load, lookml_path):
-    mock_parse_args.return_value.file = io.StringIO()
-    mock_parse_args.return_value.log_level = logging.WARN
-    mock_load.return_value = {"a": "1"}
-    lkml.cli()
-
-
 def test_load_with_bad_argument_raises_type_error():
     with pytest.raises(TypeError):
         lkml.load(stream=100)
+
+
+def test_parse_default_option(lookml_path):
+    args = lkml.parse_args([lookml_path])
+    assert args.json is True
+    assert args.lookml is False
+
+
+def test_parse_options(lookml_path):
+    args = lkml.parse_args([lookml_path, "--json"])
+    assert args.json is True
+
+    args = lkml.parse_args([lookml_path, "--lookml"])
+    assert args.lookml is True
+
+    with pytest.raises(SystemExit):
+        args = lkml.parse_args([lookml_path, "--json", "--lookml"])
+
+
+def test_run_cli_default_option(lookml_path, capsys):
+    with patch("sys.argv", ["file.py", lookml_path]):
+        lkml.cli()
+        captured = capsys.readouterr()
+        assert json.loads(captured.out) is not None
+        assert captured.err == ""
+
+
+def test_run_cli_options(lookml_path, capsys):
+    with patch("sys.argv", ["file.py", "--json", lookml_path]):
+        lkml.cli()
+        captured = capsys.readouterr()
+        assert json.loads(captured.out) is not None
+        assert captured.err == ""
+
+    with patch("sys.argv", ["file.py", "--lookml", lookml_path]):
+        lkml.cli()
+        captured = capsys.readouterr()
+        assert lkml.load(captured.out) is not None
+        assert captured.err == ""