Reject invalid cookbook CLI state (#1531)

tests/test_cookbook_cli_state.py

@@ -0,0 +1,30 @@
+import importlib.machinery
+import importlib.util
+import io
+from pathlib import Path
+
+import pytest
+
+
+ROOT = Path(__file__).resolve().parents[1]
+
+
+def _load_cli():
+    path = ROOT / "scripts" / "odysseus-cookbook"
+    loader = importlib.machinery.SourceFileLoader("odysseus_cookbook_cli", str(path))
+    spec = importlib.util.spec_from_loader(loader.name, loader)
+    module = importlib.util.module_from_spec(spec)
+    loader.exec_module(module)
+    return module
+
+
+def test_state_set_rejects_non_object_json(tmp_path, monkeypatch, capsys):
+    cli = _load_cli()
+    cli._STATE_PATH = tmp_path / "cookbook_state.json"
+    monkeypatch.setattr(cli.sys, "stdin", io.StringIO("[]"))
+
+    with pytest.raises(SystemExit):
+        cli.cmd_state_set(type("Args", (), {})())
+
+    assert "expected a JSON object" in capsys.readouterr().err
+    assert not cli._STATE_PATH.exists()