pagination page generator

a.js

const PAGES_ON_ENDS = 3

function getPages (currentPage, perPage, total) {
    let maxPage = Math.floor(total / perPage)
    let lower = Math.max(currentPage - PAGES_ON_ENDS, 0)
    let upper = Math.min(currentPage + PAGES_ON_ENDS, maxPage)

    return Array.from(Array(upper - lower + 1), (_, i) => lower + i)
}

b.js

const PAGES_ON_ENDS = 3

function getPages (currentPage, perPage, total) {
    let maxPage = Math.floor(total / perPage)
    let arr = []

    let lower = Math.max(currentPage - PAGES_ON_ENDS, 0)
    let upper = Math.min(currentPage + PAGES_ON_ENDS, maxPage)

    for (let i = lower; i <= upper; i++) {
        arr.push(i)
    }

    return arr
}