Extract samples without replacement using TypeScript.

getSamplesWithoutReplacement.ts

/**
* Extract n samples from list without replacement in O(|list|)
* @param {Object[]} list - array containing elements
* @param {number} n - size of the extraction
* @returns {Object[]} new array contains extracted elements
*/
function getSamplesWithoutReplacement<T>(list: T[], n: number): T[] {
    if (n <= 0) return []
    
    list = [...list]
    if (n >= list.length) return list
    
    for (let k = 0; k < n; ++k) {
        const target = Math.floor(Math.random() * (list.length - k)) + k;
        [list[k], list[target]] = [list[target], list[k]]
    }
    list.length = n
    return list
}

Also you can use this function for permutating list. It's special case of n = list.length.

function permutateList<T>(list: T[]): T[] {
    list = [...list];

    for (let k = 0; k < list.length; ++k) {
        const target = Math.floor(Math.random() * (list.length - k)) + k;
        [list[k], list[target]] = [list[target], list[k]];
    }
    return list;
}