GoScrobble/web/node_modules/es-abstract/5/AbstractEqualityComparison.js

38 lines
1.1 KiB
JavaScript

'use strict';
var ToNumber = require('./ToNumber');
var ToPrimitive = require('./ToPrimitive');
var Type = require('./Type');
// https://262.ecma-international.org/5.1/#sec-11.9.3
module.exports = function AbstractEqualityComparison(x, y) {
var xType = Type(x);
var yType = Type(y);
if (xType === yType) {
return x === y; // ES6+ specified this shortcut anyways.
}
if (x == null && y == null) {
return true;
}
if (xType === 'Number' && yType === 'String') {
return AbstractEqualityComparison(x, ToNumber(y));
}
if (xType === 'String' && yType === 'Number') {
return AbstractEqualityComparison(ToNumber(x), y);
}
if (xType === 'Boolean') {
return AbstractEqualityComparison(ToNumber(x), y);
}
if (yType === 'Boolean') {
return AbstractEqualityComparison(x, ToNumber(y));
}
if ((xType === 'String' || xType === 'Number') && yType === 'Object') {
return AbstractEqualityComparison(x, ToPrimitive(y));
}
if (xType === 'Object' && (yType === 'String' || yType === 'Number')) {
return AbstractEqualityComparison(ToPrimitive(x), y);
}
return false;
};