30 lines
1.0 KiB
TypeScript
30 lines
1.0 KiB
TypeScript
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import { describe, it, expect } from 'vitest';
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import { nextSlideshowSpeed, SLIDESHOW_SPEEDS, type SlideshowSpeed } from '@/lib/slideshow';
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describe('nextSlideshowSpeed', () => {
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it('cycles off → 3s → 5s → 10s → off', () => {
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expect(nextSlideshowSpeed(null)).toBe(3);
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expect(nextSlideshowSpeed(3)).toBe(5);
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expect(nextSlideshowSpeed(5)).toBe(10);
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expect(nextSlideshowSpeed(10)).toBeNull();
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});
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it('returns to off after one full cycle, so the key always lets go', () => {
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let speed: SlideshowSpeed = null;
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for (let i = 0; i < SLIDESHOW_SPEEDS.length; i++) speed = nextSlideshowSpeed(speed);
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expect(speed).toBeNull();
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});
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it('never yields a speed outside the advertised set', () => {
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let speed: SlideshowSpeed = null;
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for (let i = 0; i < 20; i++) {
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speed = nextSlideshowSpeed(speed);
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expect(SLIDESHOW_SPEEDS).toContain(speed);
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}
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});
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it('re-enters the cycle from an unrecognised value rather than sticking', () => {
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expect(nextSlideshowSpeed(7 as SlideshowSpeed)).toBe(3);
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});
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});
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