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.tip

ยท one of the small things

Set has union and difference now

You can stop spreading and filtering to do set operations.

const a = new Set([1, 2, 3]);
const b = new Set([2, 3, 4]);
a.union(b);          // {1, 2, 3, 4}
a.intersection(b);   // {2, 3}
a.difference(b);     // {1}
a.isSubsetOf(b);     // false

They shipped in Node 22 and in current browsers. The method names are the maths names, so the code reads the way you meant it.

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