feat(mcp-macro): add compute_percentile + classify_extreme pure helpers

services/mcp-macro/tests/test_cot.py

@@ -0,0 +1,44 @@
+from __future__ import annotations
+
+from mcp_macro.cot import classify_extreme, compute_percentile
+
+
+def test_compute_percentile_basic():
+    history = [10, 20, 30, 40, 50, 60, 70, 80, 90, 100]
+    assert compute_percentile(50, history) == 50.0
+    assert compute_percentile(10, history) == 10.0
+    assert compute_percentile(100, history) == 100.0
+
+
+def test_compute_percentile_value_below_min():
+    history = [10, 20, 30]
+    assert compute_percentile(5, history) == 0.0
+
+
+def test_compute_percentile_value_above_max():
+    history = [10, 20, 30]
+    assert compute_percentile(40, history) == 100.0
+
+
+def test_compute_percentile_empty_history():
+    assert compute_percentile(50, []) is None
+
+
+def test_classify_extreme_below_threshold():
+    assert classify_extreme(3.0) == "extreme_short"
+    assert classify_extreme(5.0) == "extreme_short"  # boundary inclusive
+
+
+def test_classify_extreme_above_threshold():
+    assert classify_extreme(96.0) == "extreme_long"
+    assert classify_extreme(95.0) == "extreme_long"  # boundary inclusive
+
+
+def test_classify_extreme_neutral():
+    assert classify_extreme(50.0) == "neutral"
+    assert classify_extreme(94.99) == "neutral"
+    assert classify_extreme(5.01) == "neutral"
+
+
+def test_classify_extreme_none_input():
+    assert classify_extreme(None) == "neutral"