"""Thin CLI smoke coverage for `giant rollout` (issues.md Issue 5) — confirms
the CheckpointCompatibilityError raised by giant.checkpoint_io.load_for_inference
surfaces as a clean typer.Exit(1) with the expected message, end-to-end
through the CLI, not just at the giant.checkpoint_io unit level."""

from __future__ import annotations

import torch
from typer.testing import CliRunner

from giant.cli import app

runner = CliRunner()


def test_rollout_exits_1_on_checkpoint_missing_model_config(tmp_path):
    checkpoint = tmp_path / "bad.pt"
    torch.save({"sec_decoder": {}, "normalizer": {"sec_phys": {}}}, checkpoint)

    result = runner.invoke(
        app,
        [
            "rollout",
            "dummy.parquet",
            "--checkpoint",
            str(checkpoint),
            "--geometry",
            "dummy_geometry.pkl",
        ],
    )

    assert result.exit_code == 1
    assert "checkpoint has no model_config" in result.output