tests/test_stdlib_utils.py

"""Tests for generic package utility helpers."""

from __future__ import annotations

import pytest

import kscrape.utils as ut


def test_deep_get_reads_nested_values_and_returns_default() -> None:
    """Read nested mapping values without exposing missing-key errors."""
    data = {"source": {"request": {"limit": 20}}}

    assert ut.deep_get(data, ("source", "request", "limit")) == 20
    assert ut.deep_get(data, ("source", "missing"), "default") == "default"
    assert ut.deep_get(data, ("source", "request", "limit", "extra")) is None


def test_deep_set_creates_mappings_and_raises_for_empty_keypath() -> None:
    """Create intermediate dictionaries for nested writes."""
    data: dict[str, object] = {}

    ut.deep_set(data, ("source", "request", "limit"), 20)

    assert data == {"source": {"request": {"limit": 20}}}
    with pytest.raises(IndexError):
        ut.deep_set(data, (), "value")


def test_deep_right_merge_does_not_mutate_inputs() -> None:
    """Recursively overlay mapping leaves while retaining both source mappings."""
    base = {"source": {"limit": 20, "rating": "s"}, "asset": "original"}
    overlay = {"source": {"limit": 10}, "asset": "sample"}

    assert ut.deep_right_merge(base, overlay) == {
        "source": {"limit": 10, "rating": "s"},
        "asset": "sample",
    }
    assert base["source"] == {"limit": 20, "rating": "s"}
    assert overlay["source"] == {"limit": 10}


def test_timer_prints_its_label(capsys: pytest.CaptureFixture[str]) -> None:
    """Provide a short timing report for manual diagnostic blocks.

    :param capsys: Captured standard output supplied by pytest.
    :return: None.
    """
    with ut.timer("download check"):
        pass

    assert "download check finished in" in capsys.readouterr().out