string dibagi menjadi tiga kombinasi non kosong JS

const string = "abcd";

const array = string.split("");

const output = array.reduce((carry, _, idx, arr) => {
    if (idx < arr.length - 1) {
        const str = arr[idx] + arr[idx + 1];
        const subArray = [...arr];
        subArray.splice(idx, 2, str);
        carry.push(subArray);
    }
    return carry;
}, []);

console.log(output);
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