range-spec.ts

import '../iterablehelpers';
import {
  elementAt,
  first,
  isEmpty,
  last,
  range,
  sequenceEqual,
  toArray,
} from 'ix/iterable/index.js';
import { skip, take } from 'ix/iterable/operators/index.js';

test('Iterable#range produces correct sequence', () => {
  const rangeSequence = range(1, 100);
  let expected = 0;

  for (const item of rangeSequence) {
    expected++;
    expect(expected).toBe(item);
  }

  expect(100).toBe(expected);
});

test('Iterable#range toArray produce correct result', () => {
  const arr = toArray(range(1, 100));

  for (let i = 0; i < arr.length; i++) {
    expect(i + 1).toBe(arr[i]);
  }
});

test('Iterable#range not enumerated after end', () => {
  const rangeEnum = range(1, 1);

  const it = rangeEnum[Symbol.iterator]();

  expect(it.next().done).toBeFalsy();
  expect(it.next().done).toBeTruthy();
  expect(it.next().done).toBeTruthy();
});

test('Iterable#range negative start', () => {
  const start = -5;
  const count = 1;
  const expected = [-5];

  expect(sequenceEqual(expected, range(start, count))).toBeTruthy();
});

test('Iterable#range arbitrary start', () => {
  const start = 12;
  const count = 6;
  const expected = [12, 13, 14, 15, 16, 17];

  expect(sequenceEqual(expected, range(start, count))).toBeTruthy();
});

test('Iterable#range take', () => {
  expect(sequenceEqual(range(0, 10), range(0, 10).pipe(take(10)))).toBeTruthy();
});

test('Iterable#range take excessive', () => {
  expect(sequenceEqual(range(0, 10), range(0, 10).pipe(take(Infinity)))).toBeTruthy();
});

test('Iterable#range skip', () => {
  expect(sequenceEqual(range(10, 10), range(0, 20).pipe(skip(10)))).toBeTruthy();
});

test('Iterable#range skip excessive', () => {
  expect(isEmpty(range(0, 10).pipe(skip(20)))).toBeTruthy();
});

test('Iterable#range skip take can be only one', () => {
  expect(sequenceEqual([1], range(1, 10).pipe(take(1)))).toBeTruthy();
  expect(sequenceEqual([2], range(1, 10).pipe(skip(1), take(1)))).toBeTruthy();
  expect(sequenceEqual([3], range(1, 10).pipe(take(3), skip(2)))).toBeTruthy();
  expect(sequenceEqual([1], range(1, 10).pipe(take(3), take(1)))).toBeTruthy();
});

test('Iterable#range elementAt', () => {
  expect(4).toBe(elementAt(range(0, 10), 4));
});

test('Iterable#range elementAt excessive', () => {
  expect(undefined).toBe(elementAt(range(52, 10), 100));
});

test('Iterable#range first', () => {
  expect(57).toBe(first(range(57, 1000000000)));
});

test('Iterable#range last', () => {
  expect(156).toBe(last(range(57, 100)));
});