Constnium/node_modules/es-abstract/2018/AbstractEqualityComparison.js
2022-06-23 02:27:43 +02:00

37 lines
1.1 KiB
JavaScript

'use strict';
var ToNumber = require('./ToNumber');
var ToPrimitive = require('./ToPrimitive');
var Type = require('./Type');
// https://ecma-international.org/ecma-262/6.0/#sec-abstract-equality-comparison
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' || xType === 'Symbol') && yType === 'Object') {
return AbstractEqualityComparison(x, ToPrimitive(y));
}
if (xType === 'Object' && (yType === 'String' || yType === 'Number' || yType === 'Symbol')) {
return AbstractEqualityComparison(ToPrimitive(x), y);
}
return false;
};