Added test to check simulation with cliffs

Author: SakshiKekre

tests/country/test_us.py

@@ -21,3 +21,23 @@ def test_us_macro_comparison():
     )
 
     sim.calculate_economy_comparison()
+
+def test_us_macro_cliff_impacts():
+    from policyengine import Simulation
+
+    sim = Simulation(
+        scope="macro",
+        country="us",
+        reform={
+            "gov.usda.snap.income.deductions.earned_income": {"2025": 0.05}
+        },
+        include_cliffs=True
+    )
+
+    result = sim.calculate_economy_comparison()
+    cliff_impact = result.model_dump().get('cliff_impact')
+
+    assert cliff_impact is not None, "Expected 'cliff_impact' to be present in the output."
+
+    assert cliff_impact["baseline"]["cliff_gap"] > 0
+    assert cliff_impact["reform"]["cliff_share"] > 0