Add affinity_parallelism_model/tests/test_core.py

affinity_parallelism_model/tests/test_core.py

@@ -0,0 +1,59 @@
+import pytest
+import math
+import random
+
+from affinity_parallelism_model import core
+
+@pytest.fixture(autouse=True)
+def set_seed():
+    random.seed(1234)
+
+
+def test_simulate_effects_keys_and_types():
+    result = core.simulate_effects(4, 'randomized')
+    # Check result type
+    assert isinstance(result, dict)
+    # Required keys
+    assert set(result.keys()) == {'bandwidth', 'retry_tail'}
+    # Type validation for fields
+    assert isinstance(result['bandwidth'], float)
+    assert isinstance(result['retry_tail'], float)
+
+
+def test_simulate_effects_value_ranges():
+    # Parallelism levels and affinity types to test
+    for parallelism, affinity in [(1, 'randomized'), (8, 'enforced')]:
+        result = core.simulate_effects(parallelism, affinity)
+        bandwidth = result['bandwidth']
+        retry_tail = result['retry_tail']
+
+        # Bandwidth should be positive
+        assert bandwidth > 0.0
+        # Retry tail should be finite and within reasonable bounds
+        assert -100.0 < retry_tail < 100.0
+
+
+def test_simulate_effects_invalid_inputs():
+    # Negative parallelism level
+    with pytest.raises(ValueError):
+        core.simulate_effects(-5, 'randomized')
+
+    # Invalid affinity value type
+    with pytest.raises(ValueError):
+        core.simulate_effects(4, 'unsupported_affinity')
+
+
+def test_deterministic_behavior_with_seed():
+    random.seed(999)
+    r1 = core.simulate_effects(4, 'randomized')
+    random.seed(999)
+    r2 = core.simulate_effects(4, 'randomized')
+    # Deterministic output when seed is fixed
+    assert r1 == r2
+
+
+def test_parallelism_scaling_trend():
+    # Higher parallelism generally increases bandwidth
+    low = core.simulate_effects(2, 'enforced')['bandwidth']
+    high = core.simulate_effects(16, 'enforced')['bandwidth']
+    assert high >= low or math.isclose(high, low, rel_tol=1e-3)