SxsnPC/node_modules/crypto-browserify/test/random-fill.js

'use strict';

var test = require('tape');
var crypto = require('../');
var Buffer = require('safe-buffer').Buffer;

test('get error message', function (t) {
	try {
		var b = crypto.randomFillSync(Buffer.alloc(10));
		t.ok(Buffer.isBuffer(b));
		t.end();
	} catch (err) {
		t.ok((/not supported/).test(err.message), '"not supported" is in error message');
		t.end();
	}
});

test('randomfill', function (t) {
	t.plan(5);
	t.equal(crypto.randomFillSync(Buffer.alloc(10)).length, 10);
	t.ok(Buffer.isBuffer(crypto.randomFillSync(Buffer.alloc(10))));
	crypto.randomFill(Buffer.alloc(10), function (ex, bytes) {
		t.error(ex);
		t.equal(bytes.length, 10);
		t.ok(Buffer.isBuffer(bytes));
		t.end();
	});
});

test('seems random', function (t) {
	var L = 1000;
	var buffer = crypto.randomFillSync(Buffer.alloc(L));

	var mean = Array.prototype.reduce.call(buffer, function (a, b) {
		return a + b;
	}, 0) / L;

	// test that the random numbers are plausably random.
	// Math.random() will pass this, but this will catch
	// terrible mistakes such as this blunder:
	// https://github.com/browserify/crypto-browserify/commit/3267955e1df7edd1680e52aeede9a89506ed2464#commitcomment-7916835

	// this doesn't check that the bytes are in a random *order*
	// but it's better than nothing.

	var expected = 256 / 2;
	var smean = Math.sqrt(mean);

	// console.log doesn't work right on testling, *grumble grumble*
	console.log(JSON.stringify([expected - smean, mean, expected + smean]));
	t.ok(mean < expected + smean);
	t.ok(mean > expected - smean);

	t.end();
});