38 lines
1.1 KiB
JavaScript
38 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;
|
|
};
|