Constnium/node_modules/es-abstract/2017/AbstractRelationalComparison.js
2022-06-23 02:27:43 +02:00

63 lines
1.6 KiB
JavaScript

'use strict';
var GetIntrinsic = require('get-intrinsic');
var $Number = GetIntrinsic('%Number%');
var $TypeError = GetIntrinsic('%TypeError%');
var $isNaN = require('../helpers/isNaN');
var $isFinite = require('../helpers/isFinite');
var isPrefixOf = require('../helpers/isPrefixOf');
var ToNumber = require('./ToNumber');
var ToPrimitive = require('./ToPrimitive');
var Type = require('./Type');
// https://262.ecma-international.org/5.1/#sec-11.8.5
// eslint-disable-next-line max-statements
module.exports = function AbstractRelationalComparison(x, y, LeftFirst) {
if (Type(LeftFirst) !== 'Boolean') {
throw new $TypeError('Assertion failed: LeftFirst argument must be a Boolean');
}
var px;
var py;
if (LeftFirst) {
px = ToPrimitive(x, $Number);
py = ToPrimitive(y, $Number);
} else {
py = ToPrimitive(y, $Number);
px = ToPrimitive(x, $Number);
}
var bothStrings = Type(px) === 'String' && Type(py) === 'String';
if (!bothStrings) {
var nx = ToNumber(px);
var ny = ToNumber(py);
if ($isNaN(nx) || $isNaN(ny)) {
return undefined;
}
if ($isFinite(nx) && $isFinite(ny) && nx === ny) {
return false;
}
if (nx === Infinity) {
return false;
}
if (ny === Infinity) {
return true;
}
if (ny === -Infinity) {
return false;
}
if (nx === -Infinity) {
return true;
}
return nx < ny; // by now, these are both nonzero, finite, and not equal
}
if (isPrefixOf(py, px)) {
return false;
}
if (isPrefixOf(px, py)) {
return true;
}
return px < py; // both strings, neither a prefix of the other. shortcut for steps c-f
};