import unittest
from guardrail_space.contract import SafetyContract


class TestSafetyContract(unittest.TestCase):
    def test_pre_post_eval(self):
        c = SafetyContract(
            contract_id="test-001",
            pre_conditions=["state['speed'] <= 1.0"],
            post_conditions=["state['completed'] == True"],
            budgets={"time": 10.0, "energy": 100.0},
            collision_rules=["state['distance_to_obstacle'] >= 0"],
        )
        self.assertTrue(c.evaluate_pre({"speed": 0.5, "distance_to_obstacle": 5}))
        self.assertFalse(c.evaluate_pre({"speed": 2.0, "distance_to_obstacle": 5}))