The shallow function does not correctly compare Set type data.

[qingzhoufeihu]

Bug Description

`const Set1 = new Set([{ a: 1 }]);
const Set2 = new Set([{ a: 1 }]);

console.log(shallow(Set1, Set2));`

The reason it returns false here is that one of the values is undefined, not because the values are different or the references are different.

const compareEntries = (valueA, valueB) => {
const mapA = valueA instanceof Map ? valueA : new Map(valueA.entries());
const mapB = valueB instanceof Map ? valueB : new Map(valueB.entries());
if (mapA.size !== mapB.size) return false;
for (const [key, value] of mapA) {
console.log("mapB.get(key)", mapB.get(key));// undefined
if (!Object.is(value, mapB.get(key))) return false;
}
return true;
};

Reproduction Link

https://stackblitz.com/edit/vitejs-vite-hbcg6a?file=src%2Fcounter.js

[dai-shi]

It's because { a: 1 } !== { a: 1 }. It's a shallow comparison, not a deep comparison.

[dbritto-dev]

@qingzhoufeihu as @dai-shi said it's shallow comparison, please keep that in mind