chunk array elements over a predicate function

chunk.js

var data = [1, 2, 3, 13, 5, 6, 7, 8, 9, 10, 11];
var predicate = element => element % 2 === 0;

function chunk(predicate, data) {
    return data.map(predicate).reduce((prev, curr, i, arr) => {
        if (curr) {
            if (prev.length) {
                let first = prev[prev.length - 1][1];
                prev.push([first, i + 1]);
            } else {
                prev.push([0, i + 1]);
            }
        } else if (!curr && (i === arr.length - 1)) {
            let first = prev[prev.length - 1][1];
            prev.push([first, i + 1]);
        }
        return prev;
    }, []).map(([first, last]) => data.slice(first, last));
}

const r=chunk(predicate, data);
console.log(r);

function chunk(predicate, data) {
    return data.reduce(function (prev, curr, i, arr) {
        var t=predicate(curr)
        if (t) {
            var first = prev.length?prev[prev.length - 1][1]:0;
            prev.push([first, i + 1]);
        } else if (!t && (i == arr.length - 1)) {
            var first = prev[prev.length - 1][1];
            prev.push([first, i + 1]);
        }
        return prev;
    }, []).map(function (indexes) {
        var first = indexes[0];
        var last = indexes[1];
        return data.slice(first, last);
    });
}