test: add checkout parse-cli-api test

tests/unit/command/test_checkout.py

@@ -0,0 +1,21 @@
+from dvc.cli import parse_args
+from dvc.command.checkout import CmdCheckout
+
+
+def test_checkout(tmp_dir, dvc, mocker):
+    cli_args = parse_args(
+        ["checkout", "foo.dvc", "bar.dvc", "--relink", "--with-deps"]
+    )
+    assert cli_args.func == CmdCheckout
+
+    cmd = cli_args.func(cli_args)
+    m = mocker.patch("dvc.repo.Repo.checkout")
+
+    assert cmd.run() == 0
+    m.assert_called_once_with(
+        targets=["foo.dvc", "bar.dvc"],
+        force=False,
+        recursive=False,
+        relink=True,
+        with_deps=True,
+    )