tests.js

/* jshint node: true, mocha: true, browser: true */

'use strict';

const assert = require('assert');
const superscript = require('./server');

const ONE_SECOND = 1000,
    HALF_A_SECOND = ONE_SECOND / 2,
    TENTH_OF_A_SECOND = ONE_SECOND / 10,
    HUNDREDTH_OF_A_SECOND = ONE_SECOND / 100;

let timer;

if ('undefined' !== typeof setTimeout) timer = setTimeout;
else if ('undefined' !== typeof window && 'undefined' !== typeof window.setTimeout) timer = window.setTimeout;
else throw new Error('superscript[tests]: cannot use “setTimeout()” nor “window.setTimeout()”');

describe('“hold()”', () => {
    var checks, start;

    const reset = () => {
        start = new Date().getTime();
        checks = 0;
    };

    const oneSecondHasElapsed = () => {
        checks++;

        return new Date().getTime() - start >= ONE_SECOND;
    };

    const yes = () => true;

    it('should work', (done) => {
        reset();
        superscript.hold(oneSecondHasElapsed, done);
    });

    it('should invoke callback immediately if check passes', (done) => {
        const checkImmediacy = () => done(1 < checks ? 'checked condition more than once' : null);
        reset();
        superscript.hold(yes, checkImmediacy);
    });

    it('should honour custom interval', (done) => {
        const FOUR_HERTZ = 250;
        const checkAccuracy = () => {
            const DELTA = new Date().getTime() - start - ONE_SECOND;
            if (0 >= DELTA) done('ran callback too soon');
            else if (DELTA >= FOUR_HERTZ) done('ran callback too late');
            else if (5 > checks) done('did not checked condition often enough');
            else if (5 < checks) done('checked condition too often');
            else done();
        };
        reset();
        superscript.hold(oneSecondHasElapsed, checkAccuracy, FOUR_HERTZ);
    });

    it('should pass along parameters to callback', (done) => {
        const x = '1',
            y = '2',
            z = '3';
        const checkParams = (a, b, c) => done(a === x && b === y && c === z ? null : 'callback did not receive right parameters');
        reset();
        superscript.hold(yes, checkParams, null, x, y, z);
    });
});

describe('“debounce()”', () => {
    let checks, start;

    it('should work', (done) => {
        const cushioned = superscript.debounce(() => {
            done(assert(Math.abs(new Date().getTime() - start - ONE_SECOND) < HUNDREDTH_OF_A_SECOND));
        }, HALF_A_SECOND);
        start = new Date().getTime();
        for (let i = 1; 6 > i; i++) timer(cushioned, i * TENTH_OF_A_SECOND);
    });

    it('should delay (but not mute) scattered events', (done) => {
        const cushioned = superscript.debounce(() => {
            assert(Math.abs(new Date().getTime() - start - HALF_A_SECOND) < HUNDREDTH_OF_A_SECOND);
            if (2 < ++checks) done();
            else start = new Date().getTime();
        }, TENTH_OF_A_SECOND);
        checks = 0;
        timer(() => {
            start = new Date().getTime();
        }, TENTH_OF_A_SECOND);
        for (let i = 1; 4 > i; i++) timer(cushioned, i * HALF_A_SECOND);
    });
});

describe('“palette()”', () => {
    const GAMUT = 23,
        RGB_REGEX = /[\dabcdef]{6}/i;

    var p;

    it('should work', (done) => {
        p = new superscript.Palette(GAMUT);
        if (!p) done('does not work');
        else if (GAMUT !== p.n) done('wrong size of palette');
        else if ('number' !== typeof p.get(0) || 'number' !== typeof p.get(GAMUT - 1)) done('cannot retrieve colours');
        else if (!p.get(parseInt(GAMUT / 2), true).match(RGB_REGEX)) done('RGB colour is incorrect');
        else done();
    });
});