49 lines
1.1 KiB
JavaScript
49 lines
1.1 KiB
JavaScript
import Random from './Random.js';
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describe('Random', () => {
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let random = null;
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beforeEach(() => {
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random = new Random();
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random.reset();
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});
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describe('.nextFloat', () => {
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it('produces values between 0 and 1', () => {
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for(let i = 0; i < 1000; ++ i) {
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const v = random.nextFloat();
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expect(v).not.toBeLessThan(0);
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expect(v).toBeLessThan(1);
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}
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});
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it('produces the same sequence when reset', () => {
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const values = [];
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for(let i = 0; i < 1000; ++ i) {
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values.push(random.nextFloat());
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}
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random.reset();
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for(let i = 0; i < 1000; ++ i) {
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expect(random.nextFloat()).toEqual(values[i]);
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}
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});
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it('produces a roughly uniform range of values', () => {
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const samples = 10000;
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const granularity = 10;
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const buckets = [];
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buckets.length = granularity;
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buckets.fill(0);
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for(let i = 0; i < samples; ++ i) {
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const v = random.nextFloat() * granularity;
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++ buckets[Math.floor(v)];
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}
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const threshold = (samples / granularity) * 0.9;
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for(let i = 0; i < granularity; ++ i) {
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expect(buckets[i]).not.toBeLessThan(threshold);
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}
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});
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});
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});
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