Source code for util.number_interval_generator_test

import statistics

import pytest

from util.number_interval_generator import (NumberInterval, NumberIntervalGenerator, POSITIVE_INFINITY)

NUMBER_OF_RANDOM_INTERVALS = 1_000




def test_equal_method():
    number_interval_1 = NumberInterval(10, 20)
    number_interval_2 = NumberInterval(10, 20)
    assert number_interval_1 == number_interval_2

    number_interval_3 = NumberInterval(10, 20)
    number_interval_4 = NumberInterval(10, 21)
    assert number_interval_3 != number_interval_4





def get_random_intervals(
        mean: int, standard_deviation: int, _lower_number_min_value: int = 0
) -> list[NumberInterval]:
    lower_number_bounds: NumberInterval = NumberInterval(
            lower_bound=_lower_number_min_value, upper_bound=POSITIVE_INFINITY
    )
    number_interval_generator = NumberIntervalGenerator(
            mean=mean,
            standard_deviation=standard_deviation,
            lower_number_bounds=lower_number_bounds,
    )
    return [
            number_interval_generator.generate_interval()
            for _ in range(NUMBER_OF_RANDOM_INTERVALS)
    ]





def get_random_numbers(
        mean: int, standard_deviation: int, _lower_number_min_value: int = 0
) -> list[int]:
    return [
            text_length.lower_bound
            for text_length in get_random_intervals(
                    mean=mean,
                    standard_deviation=standard_deviation,
                    _lower_number_min_value=_lower_number_min_value,
            )
    ]





@pytest.mark.parametrize(
        "text_length_mean,text_length_standard_deviation",
        [
                (1_000, 100),
                (100, 50),
                (200, 10),
        ],
)
def test_random_interval_distribution(text_length_mean, text_length_standard_deviation):
    random_numbers = get_random_numbers(
            mean=text_length_mean, standard_deviation=text_length_standard_deviation
    )

    actual_mean = statistics.mean(random_numbers)
    actual_standard_deviation = statistics.stdev(random_numbers)

    assert abs(text_length_mean - actual_mean) < text_length_mean / 2
    assert (
            abs(text_length_standard_deviation - actual_standard_deviation)
            < text_length_standard_deviation / 2
    )





@pytest.mark.parametrize("lower_number_min_value", [10, 100])
def test_random_numbers_intervals_are_in_bound(lower_number_min_value):
    mean = 200
    stddev = 1_000
    random_numbers = get_random_numbers(
            mean, stddev, _lower_number_min_value=lower_number_min_value
    )

    assert min(random_numbers) >= lower_number_min_value





def test_text_length_upper_bound():
    mean = 100
    standard_deviation = 100
    random_text_lengths = get_random_intervals(mean, standard_deviation)
    for random_text_length in random_text_lengths:
        if random_text_length.lower_bound >= 40:
            assert random_text_length.upper_bound - random_text_length.lower_bound >= 10
        if random_text_length.lower_bound >= 200:
            assert random_text_length.upper_bound - random_text_length.lower_bound >= 20
            assert (
                    random_text_length.upper_bound - random_text_length.lower_bound <= 200
            )