bench: add dedicated comparator microbenchmark for frozenset fast-path

5 scenarios: primitives, nested dicts, DB rows, deep nesting,
and identity types (frozenset/range/complex/Decimal/OrderedDict).

Author: KRRT7

tests/benchmarks/test_benchmark_comparator.py

@@ -0,0 +1,133 @@
+"""Benchmark comparator type dispatch performance.
+
+Exercises the fast-path frozenset lookup vs isinstance MRO traversal
+across realistic return value shapes: primitives, nested containers,
+and mixed-type structures typical of real optimization verification.
+"""
+
+from __future__ import annotations
+
+from collections import OrderedDict
+from decimal import Decimal
+
+from codeflash.verification.comparator import comparator
+
+# --- Test data: realistic return value shapes ---
+
+# 1. Flat primitives (int, bool, None, str, float, bytes) — the fast-path sweet spot
+_PRIMITIVES_A = [
+    42,
+    True,
+    None,
+    3.14,
+    "hello",
+    b"bytes",
+    0,
+    False,
+    "",
+    1.0,
+    -1,
+    None,
+    True,
+    99,
+    "world",
+    b"\x00\x01",
+    2**31,
+    0.0,
+    False,
+    None,
+]
+_PRIMITIVES_B = list(_PRIMITIVES_A)
+
+# 2. Nested dict of lists (common return value shape: API responses, parsed configs)
+_NESTED_DICT_A = {
+    "users": [{"id": i, "name": f"user_{i}", "active": i % 2 == 0, "score": i * 1.5} for i in range(50)],
+    "metadata": {"total": 50, "page": 1, "has_next": True},
+    "tags": [f"tag_{i}" for i in range(20)],
+    "config": {"timeout": 30, "retries": 3, "debug": False, "threshold": Decimal("0.95")},
+}
+_NESTED_DICT_B = {
+    "users": [{"id": i, "name": f"user_{i}", "active": i % 2 == 0, "score": i * 1.5} for i in range(50)],
+    "metadata": {"total": 50, "page": 1, "has_next": True},
+    "tags": [f"tag_{i}" for i in range(20)],
+    "config": {"timeout": 30, "retries": 3, "debug": False, "threshold": Decimal("0.95")},
+}
+
+# 3. List of tuples (common: database rows, CSV data)
+_ROWS_A = [(i, f"row_{i}", i * 0.1, i % 3 == 0, None if i % 5 == 0 else i) for i in range(200)]
+_ROWS_B = [(i, f"row_{i}", i * 0.1, i % 3 == 0, None if i % 5 == 0 else i) for i in range(200)]
+
+
+# 4. Deeply nested structure (worst case for recursive comparator)
+def _make_deep(depth: int) -> dict:
+    if depth == 0:
+        return {"leaf": True, "value": 42, "items": [1, 2, 3], "label": "end"}
+    return {"level": depth, "child": _make_deep(depth - 1), "siblings": list(range(depth))}
+
+
+_DEEP_A = _make_deep(15)
+_DEEP_B = _make_deep(15)
+
+# 5. Mixed identity types (frozenset, range, slice, OrderedDict, bytes, complex)
+_IDENTITY_TYPES_A = [
+    frozenset({1, 2, 3}),
+    range(100),
+    complex(1, 2),
+    Decimal("3.14"),
+    OrderedDict(a=1, b=2),
+    b"binary",
+    bytearray(b"mutable"),
+    memoryview(b"view"),
+    type(None),
+    True,
+    42,
+    None,
+] * 10
+_IDENTITY_TYPES_B = list(_IDENTITY_TYPES_A)
+
+
+def _compare_all_primitives() -> None:
+    for a, b in zip(_PRIMITIVES_A, _PRIMITIVES_B):
+        comparator(a, b)
+
+
+def _compare_nested_dict() -> None:
+    comparator(_NESTED_DICT_A, _NESTED_DICT_B)
+
+
+def _compare_rows() -> None:
+    comparator(_ROWS_A, _ROWS_B)
+
+
+def _compare_deep() -> None:
+    comparator(_DEEP_A, _DEEP_B)
+
+
+def _compare_identity_types() -> None:
+    for a, b in zip(_IDENTITY_TYPES_A, _IDENTITY_TYPES_B):
+        comparator(a, b)
+
+
+def test_benchmark_comparator_primitives(benchmark) -> None:
+    """20 flat primitive comparisons (int, bool, None, str, float, bytes)."""
+    benchmark(_compare_all_primitives)
+
+
+def test_benchmark_comparator_nested_dict(benchmark) -> None:
+    """Nested dict with 50-element user list, metadata, tags, config."""
+    benchmark(_compare_nested_dict)
+
+
+def test_benchmark_comparator_rows(benchmark) -> None:
+    """200 tuples of (int, str, float, bool, Optional[int])."""
+    benchmark(_compare_rows)
+
+
+def test_benchmark_comparator_deep(benchmark) -> None:
+    """15-level deep nested dict structure."""
+    benchmark(_compare_deep)
+
+
+def test_benchmark_comparator_identity_types(benchmark) -> None:
+    """120 frozenset/range/complex/Decimal/OrderedDict/bytes comparisons."""
+    benchmark(_compare_identity_types)