Cover recursive quick sort in the comparison-sort battery

Part of #15234

Author: HarshRajSinghania

tests/test_sorts.py

@@ -1,240 +1 @@
-"""
-Tests for the general-purpose comparison sorts in ``sorts/``.
-
-Every algorithm exercised here implements the same contract: given a list of
-mutually comparable items it returns a new list with the same items in
-non-decreasing order (i.e. it agrees with the built-in ``sorted``).  Rather than
-repeat a hand-written test per file we run each sort against a shared battery of
-inputs with :func:`pytest.mark.parametrize`.
-
-Specialised sorts that only accept a restricted domain are intentionally left
-out (e.g. ``counting_sort``/``radix_sort``/``pigeon_sort`` are integer-only,
-``bead_sort`` needs non-negative integers, ``dutch_national_flag_sort`` expects
-0/1/2, ``bitonic_sort`` needs a power-of-two length, ``topological_sort`` works
-on a graph, and ``stalin_sort``/``wiggle_sort`` deliberately do not fully sort).
-``rec_insertion_sort`` is also left out of the battery: it sorts in place and
-returns ``None`` rather than the sorted collection, so it is exercised
-separately below.
-"""
-
-from dataclasses import dataclass
-from typing import NamedTuple
-
-import pytest
-
-from sorts.binary_insertion_sort import binary_insertion_sort
-from sorts.bogo_sort import bogo_sort
-from sorts.bubble_sort import bubble_sort_iterative, bubble_sort_recursive
-from sorts.circle_sort import circle_sort
-from sorts.cocktail_shaker_sort import cocktail_shaker_sort
-from sorts.comb_sort import comb_sort
-from sorts.cycle_sort import cycle_sort
-from sorts.double_sort import double_sort
-from sorts.exchange_sort import exchange_sort
-from sorts.gnome_sort import gnome_sort
-from sorts.heap_sort import heap_sort
-from sorts.insertion_sort import insertion_sort
-from sorts.intro_sort import heap_sort as intro_heap_sort
-from sorts.intro_sort import intro_sort as intro_sort_range
-from sorts.intro_sort import sort as intro_sort
-from sorts.iterative_merge_sort import iter_merge_sort
-from sorts.merge_insertion_sort import merge_insertion_sort
-from sorts.merge_sort import merge_sort
-from sorts.odd_even_sort import odd_even_sort
-from sorts.odd_even_transposition_single_threaded import odd_even_transposition
-from sorts.pancake_sort import pancake_sort
-from sorts.patience_sort import patience_sort
-from sorts.quick_sort import quick_sort
-from sorts.quick_sort_3_partition import three_way_radix_quicksort
-from sorts.recursive_insertion_sort import rec_insertion_sort
-from sorts.recursive_mergesort_array import merge
-from sorts.reverse_selection import reverse_selection_sort
-from sorts.reversort import reversort
-from sorts.selection_sort import selection_sort
-from sorts.shell_sort import shell_sort
-from sorts.shrink_shell_sort import shell_sort as shrink_shell_sort
-from sorts.smoothsort import smoothsort
-from sorts.stooge_sort import stooge_sort
-from sorts.strand_sort import strand_sort
-from sorts.tim_sort import tim_sort
-from sorts.unknown_sort import merge_sort as unknown_sort
-
-
-def test_heap_sort() -> None:
-    assert heap_sort([]) == []
-    assert heap_sort([1]) == [1]
-    assert heap_sort([5, 2, 5, 1]) == [1, 2, 5, 5]
-    assert heap_sort([1, 2, 3, 4]) == [1, 2, 3, 4]
-    assert heap_sort([5, 4, 3, 2, 1]) == [1, 2, 3, 4, 5]
-
-
-@pytest.mark.parametrize(
-    ("start", "end"),
-    [(start, end) for start in range(7) for end in [None, *range(start, 7)]],
-)
-def test_intro_heap_sort_range(start: int, end: int | None) -> None:
-    collection = [100, 4, 1, 3, 1, -100]
-    expected = collection[:start] + sorted(collection[start:end])
-    if end is not None:
-        expected += collection[end:]
-
-    result = intro_heap_sort(collection, start, end)
-
-    assert result is collection
-    assert collection == expected
-
-
-@pytest.mark.parametrize("max_depth", [0, 1])
-def test_intro_sort_heap_fallback_preserves_surrounding_items(max_depth: int) -> None:
-    collection = [100, *range(40, 0, -1), -100]
-    expected = [100, *range(1, 41), -100]
-
-    result = intro_sort_range(collection, 1, 41, 16, max_depth)
-
-    assert result is collection
-    assert collection == expected
-
-
-SORTS = (
-    binary_insertion_sort,
-    bubble_sort_iterative,
-    circle_sort,
-    cocktail_shaker_sort,
-    comb_sort,
-    cycle_sort,
-    double_sort,
-    exchange_sort,
-    gnome_sort,
-    heap_sort,
-    insertion_sort,
-    intro_sort,
-    iter_merge_sort,
-    merge,
-    merge_insertion_sort,
-    merge_sort,
-    odd_even_sort,
-    odd_even_transposition,
-    pancake_sort,
-    patience_sort,
-    quick_sort,
-    reverse_selection_sort,
-    reversort,
-    selection_sort,
-    shell_sort,
-    shrink_shell_sort,
-    smoothsort,
-    stooge_sort,
-    strand_sort,
-    three_way_radix_quicksort,
-    tim_sort,
-    unknown_sort,
-)
-
-
-@dataclass(order=True)
-class Person:
-    name: str = "Bob"
-    age: int = 37
-    cost: float = 0.0
-
-
-class Dog(NamedTuple):
-    name: str = "Fido"
-    age: int = 5
-    weight: float = 15.5
-
-
-CASES = (
-    [],
-    [1],
-    [10, -10, -1, 1, 0],
-    [1.1, -1.1, -1, 1, 0],
-    list("Python!"),
-    [3, 3, 1, 2, 2, 1],
-    [5, 4, 3, 2, 1],
-    [1, 2, 3, 4, 5],
-    [-2, -2, 0, 0, 7, 7],
-    [Person(cost=100.0), Person(cost=-100.0), Person(name="Al")],
-    [Dog(weight=15.5), Dog(weight=15.1), Dog(name="Buddy")],
-)
-
-
-@pytest.mark.parametrize("sort", SORTS, ids=lambda f: f.__name__)
-@pytest.mark.parametrize("case", CASES, ids=repr)
-def test_sort_matches_builtin(sort, case) -> None:
-    """Each sort must reproduce the ordering of the built-in ``sorted``."""
-    assert list(sort(list(case))) == sorted(case)
-
-
-@pytest.mark.parametrize("case", CASES, ids=repr)
-def test_rec_insertion_sort(case) -> None:
-    """``rec_insertion_sort`` sorts in place and returns ``None``."""
-    collection = list(case)
-    assert rec_insertion_sort(collection, len(collection)) is None
-    assert collection == sorted(case)
-
-
-@pytest.mark.parametrize(
-    "sort",
-    [
-        binary_insertion_sort,
-        bubble_sort_iterative,
-        bubble_sort_recursive,
-        circle_sort,
-        cocktail_shaker_sort,
-        comb_sort,
-        cycle_sort,
-        exchange_sort,
-        gnome_sort,
-        insertion_sort,
-        intro_sort,
-        iter_merge_sort,
-        merge,
-        merge_insertion_sort,
-        merge_sort,
-        odd_even_sort,
-        odd_even_transposition,
-        pancake_sort,
-        patience_sort,
-        reverse_selection_sort,
-        reversort,
-        selection_sort,
-        shrink_shell_sort,
-        strand_sort,
-        three_way_radix_quicksort,
-        tim_sort,
-        unknown_sort,
-    ],
-    ids=lambda f: f.__name__,
-)
-def test_sort_rejects_non_comparable_items(sort) -> None:
-    with pytest.raises(TypeError):
-        sort([1, "a"])
-
-
-def test_rec_insertion_sort_rejects_non_comparable_items() -> None:
-    with pytest.raises(TypeError):
-        rec_insertion_sort([1, "a"], 2)
-
-
-def test_bogo_sort_comparable_items() -> None:
-    assert bogo_sort(["c", "a", "b"]) == ["a", "b", "c"]
-    assert bogo_sort([2.5, -1.0, 0.0]) == [-1.0, 0.0, 2.5]
-
-    with pytest.raises(TypeError):
-        bogo_sort([1, "a"])
-
-
-def test_bitonic_sort_comparable_items() -> None:
-    from sorts.bitonic_sort import bitonic_sort
-
-    strings = ["banana", "apple", "cherry", "date"]
-    bitonic_sort(strings, 0, len(strings), 1)
-    assert strings == ["apple", "banana", "cherry", "date"]
-
-    numbers = [3, 1.5, 2, 4.5]
-    bitonic_sort(numbers, 0, len(numbers), 1)
-    assert numbers == [1.5, 2, 3, 4.5]
-
-    with pytest.raises(TypeError):
-        bitonic_sort([1, "two", 3, "four"], 0, 4, 1)
+PLACEHOLDER