integer/test/12.from-string.js

Native 64-bit integers with overflow protection.

'use strict';
const expect = require('chai').expect;
const Integer = require('../.');
const fromString = Integer.fromString;

function equal(a, b) {
	expect(a).to.be.an.instanceof(Integer);
	expect(a.toString()).to.equal(b);
}

describe('Integer.fromString()', function () {
	it('should work with a base-10 string argument', function () {
		equal(fromString('0'), '0');
		equal(fromString('123'), '123');
		equal(fromString('-123'), '-123');
		equal(fromString('1'), '1');
		equal(fromString('2'), '2');
		equal(fromString('-1'), '-1');
		equal(fromString('-2'), '-2');
		equal(fromString('0005'), '5');
		equal(fromString('0000'), '0');
		equal(fromString('-0000'), '0');
		equal(fromString('450.'), '450');
		equal(fromString('500.00'), '500');
		equal(fromString('0.0'), '0');
		equal(fromString('.0'), '0');
		equal(fromString('0.'), '0');
		equal(fromString('-.0'), '0');
		equal(fromString('-0.'), '0');
		equal(fromString('9223372036854775807'), '9223372036854775807');
		equal(fromString('-9223372036854775808'), '-9223372036854775808');
	});
	it('should throw when the argument is an unaccepted type', function () {
		expect(() => fromString()).to.throw(TypeError);
		expect(() => fromString(undefined)).to.throw(TypeError);
		expect(() => fromString(null)).to.throw(TypeError);
		expect(() => fromString([])).to.throw(TypeError);
		expect(() => fromString(new String('123'))).to.throw(TypeError);
		expect(() => fromString(123)).to.throw(TypeError);
		expect(() => fromString(Integer(123))).to.throw(TypeError);
	});
	it('should throw when the argument is a string with non-integer characters', function () {
		expect(() => fromString('a')).to.throw(TypeError);
		expect(() => fromString('100g')).to.throw(TypeError);
		expect(() => fromString('5.5')).to.throw(TypeError);
		expect(() => fromString('5.00050')).to.throw(TypeError);
		expect(() => fromString('5.0000000000000000000001')).to.throw(TypeError);
		expect(() => fromString('5..')).to.throw(TypeError);
		expect(() => fromString('5.0.')).to.throw(TypeError);
		expect(() => fromString('5.0.0')).to.throw(TypeError);
		expect(() => fromString('.')).to.throw(TypeError);
		expect(() => fromString('-.')).to.throw(TypeError);
		expect(() => fromString(' . ')).to.throw(TypeError);
		expect(() => fromString(' -. ')).to.throw(TypeError);
		expect(() => fromString('.p')).to.throw(TypeError);
		expect(() => fromString(' .p ')).to.throw(TypeError);
		expect(() => fromString(' -.. ')).to.throw(TypeError);
		expect(() => fromString('.-')).to.throw(TypeError);
		expect(() => fromString('Infinity')).to.throw(TypeError);
	});
	it('should throw when the argument is a string of a number larger than 64 bits', function () {
		expect(() => fromString('9223372036854775808')).to.throw(RangeError);
		expect(() => fromString('-9223372036854775809')).to.throw(RangeError);
		expect(() => fromString('18446744073709551614')).to.throw(RangeError);
		expect(() => fromString('18446744073709551616')).to.throw(RangeError);
		expect(() => fromString('340282366920938463463374607431768211454')).to.throw(RangeError);
		expect(() => fromString('340282366920938463463374607431768211456')).to.throw(RangeError);
	});
	it('should accept valid strings with whitespace padding', function () {
		equal(fromString('   123    '), '123');
		equal(fromString('\t-123   '), '-123');
		equal(fromString('  0005   '), '5');
		equal(fromString(' 0000 '), '0');
		equal(fromString('\n-0000\t'), '0');
		equal(fromString(' \n450.\t\t'), '450');
		equal(fromString(' \n500.00\t \n '), '500');
		equal(fromString('450. '), '450');
		equal(fromString('  -.0  '), '0');
		equal(fromString('  -0.  '), '0');
	});
	it('should throw when the argument is a string containing invalid whitespace', function () {
		expect(() => fromString('1 23')).to.throw(TypeError);
		expect(() => fromString(' - 123')).to.throw(TypeError);
		expect(() => fromString('000 5')).to.throw(TypeError);
		expect(() => fromString('00 00')).to.throw(TypeError);
		expect(() => fromString('- 0000')).to.throw(TypeError);
		expect(() => fromString('450 .')).to.throw(TypeError);
		expect(() => fromString('450. 0')).to.throw(TypeError);
		expect(() => fromString('500 . 00')).to.throw(TypeError);
		expect(() => fromString('- .0')).to.throw(TypeError);
		expect(() => fromString('-. 0')).to.throw(TypeError);
		expect(() => fromString('-0 .')).to.throw(TypeError);
		expect(() => fromString('- 0.')).to.throw(TypeError);
		expect(() => fromString('')).to.throw(TypeError);
		expect(() => fromString('   \r\t ')).to.throw(TypeError);
	});
	it('should work with strings of other bases', function () {
		equal(fromString('zz', 36), '1295');
		equal(fromString('-1010101', 2), '-85');
		equal(fromString('fffef29edabcdf', 16), '72056437061893343');
		equal(fromString('   zZ.00000   ', 36), '1295');
		equal(fromString('\t\t-1010101.', 2), '-85');
		equal(fromString(' -fFFef29eDabCdf.   ', 16), '-72056437061893343');
		expect(() => fromString('10121', 2)).to.throw(TypeError);
		expect(() => fromString('zz', 35)).to.throw(TypeError);
		expect(() => fromString('z{', 36)).to.throw(TypeError);
		expect(() => fromString('z[', 36)).to.throw(TypeError);
		expect(() => fromString('`a', 36)).to.throw(TypeError);
		expect(() => fromString('gffef29edabcdf', 16)).to.throw(TypeError);
		expect(() => fromString('5.0.0', 36)).to.throw(TypeError);
		expect(() => fromString('.', 36)).to.throw(TypeError);
		expect(() => fromString('-.', 36)).to.throw(TypeError);
		expect(() => fromString('.{', 36)).to.throw(TypeError);
		expect(() => fromString(' .{ ', 36)).to.throw(TypeError);
		expect(() => fromString(' -.. ', 36)).to.throw(TypeError);
		expect(() => fromString('.-', 36)).to.throw(TypeError);
	});
	it('should only allow bases within 2 - 36', function () {
		expect(() => fromString('0', 1)).to.throw(RangeError);
		expect(() => fromString('0', 37)).to.throw(RangeError);
		expect(() => fromString('0', {})).to.throw(TypeError);
		expect(() => fromString('0', new Number(10))).to.throw(TypeError);
		expect(() => fromString('0', '10')).to.throw(TypeError);
		expect(() => fromString('0', Integer(10))).to.throw(TypeError);
		expect(() => fromString('0', -1)).to.throw(TypeError);
		expect(() => fromString('0', 0xffffffff + 10)).to.throw(TypeError);
		expect(() => fromString('0', 0x7fffffff + 10)).to.throw(RangeError);
	});
	it('should accept default values as an alternative to throwing exceptions', function () {
		expect(() => fromString(undefined, 36, '0')).to.throw(TypeError);
		expect(() => fromString(123, 36, '0')).to.throw(TypeError);
		expect(() => fromString(Integer(123), 36, '0')).to.throw(TypeError);
		equal(fromString('a', 10, '123'), '123');
		equal(fromString('5.0000000000000000000001', 36, Integer(456)), '456');
		equal(fromString('', 36, '-zz'), '-1295');
		equal(fromString('2', 2, '10101'), '21');
		equal(fromString('9223372036854775808', 10, Integer(555)), '555');
		expect(fromString('18446744073709551616', 10, Integer.ONE)).to.equal(Integer.ONE);
	});
	it('should throw when the default value is not valid', function () {
		expect(() => fromString('', 10, 123)).to.throw(TypeError);
		expect(() => fromString('', 10, new String('123'))).to.throw(TypeError);
		expect(() => fromString('', 10, '2.2')).to.throw(TypeError);
		expect(() => fromString('', 2, '\t-.\t')).to.throw(TypeError);
		expect(() => fromString('', 16, 'g')).to.throw(TypeError);
		expect(() => fromString('', 36, '')).to.throw(TypeError);
	});
});