The implementation of this LRU cache does not enforce the documented behavior:

maxSize
Required
Type: number

The maximum number of items before evicting the least recently used items.

Running this code snippet produces true in the console:

const m = new QuickLRU({
    maxSize: 2
});
m.set("key1", "value1");
m.set("key2", "value2");
m.set("key3", "value3");
console.log(m.has("key1"));

The cache should only be able to store 2 items and when adding a total of 3 items to the list, the first key-value pair (key1-value1) should be evicted. However, from the result of executing the code, you can see that key1 is still in the cache.