random.mjs

/** nodejs doesnt support window.crypt */
import {expect} from "chai"
import {getGlobal} from "../../../../application/source/types/global.mjs";
import * as Crypto from "@peculiar/webcrypto";
import {random} from "../../../../application/source/math/random.mjs";

const global = getGlobal();

if (!global['crypto']) {
    global['crypto'] = new Crypto.Crypto();
}

describe('Math', function () {

    describe('.random()', function () {


        it('a greater b should throw error ', function () {
            expect(() => random(10, 2)).to.throw(Error);
        });

        it(' should return a number ', function () {
            let r = random();
            expect(r).that.is.a('number');
        });

        it(' should return a number ', function () {
            expect(() => random(5, 6)).to.throw(Error);
        });
        
        it(' should throw Error we cannot generate numbers larger than 53 bits.', function () {
            expect(() => random(-999999999, 99999999999999999999)).to.throw(Error);
        });

        [
            [1, 100],
            [500, 600],
            [100, 1000]
        ].forEach(function (data) {

            let a = data.shift()
            let b = data.shift()

            let r = random(a, b);

            it(r + ' should return value between ' + a + ' ' + b, function () {
                expect(r >= a).to.be.true;
                expect(r <= b).to.be.true;
            });
        });

        [
            [1, 100],
            [500, 600],
            [100, 1000]
        ].forEach(function (data) {

            let a = data.shift()
            let b = data.shift()

            let sum = 0;
            const rounds = 500

            for (let i = 0, max = rounds; i < max; i++) {
                sum += random(a, b);
            }

            let avg = sum / rounds;

            it(avg + ' should between ' + a + ' ' + b, function () {
                expect(avg > a).to.be.true
                expect(avg < b).to.be.true
            })


        })


    })


})