advent-2019-1-a.js

const inputs = ['116860','130144','79347','120725','137692','139037','72089','133224','102168','100679','122298','132969','109196','85162','66316','68461','87608','108091','71061','85477','97748','105766','141169','94553','98932','134376','69822','104858','102584','59682','52092','105784','144100','83695','130436','105447','133102','82770','68684','103878','136774','71462','96828','74743','127523','124145','148013','103862','80052','74095','130394','125589','137576','111299','69311','63144','119014','136084','94348','109511','102493','117791','76202','138442','72724','104579','80285','56847','145460','132255','58264','60460','98995','63343','51207','133619','126155','130707','105010','104589','128527','67715','71823','82517','74115','135483','82230','127410','128969','140127','59133','145973','109430','103608','113203','133402','123971','71761','114178','52940'];

const fuel = (weight) => Math.floor(weight / 3) - 2;

const test = (input, expected) => {
    const actual = fuel(input);
    if (expected !== actual) {
        throw new Error(`Expected [${expected}] but got [${actual}]`);
    }
}

test(12, 2)
test(14, 2)
test(1969, 654)
test(100756, 33583)

console.log("total: ", inputs.reduce((prev, current) => prev + fuel(current), 0))

advent-2019-1-b.js

const inputs = ['116860','130144','79347','120725','137692','139037','72089','133224','102168','100679','122298','132969','109196','85162','66316','68461','87608','108091','71061','85477','97748','105766','141169','94553','98932','134376','69822','104858','102584','59682','52092','105784','144100','83695','130436','105447','133102','82770','68684','103878','136774','71462','96828','74743','127523','124145','148013','103862','80052','74095','130394','125589','137576','111299','69311','63144','119014','136084','94348','109511','102493','117791','76202','138442','72724','104579','80285','56847','145460','132255','58264','60460','98995','63343','51207','133619','126155','130707','105010','104589','128527','67715','71823','82517','74115','135483','82230','127410','128969','140127','59133','145973','109430','103608','113203','133402','123971','71761','114178','52940'];

const fuel = (weight) => Math.floor(weight / 3) - 2;

const fuelCal = (weight) => {
    let totalFuel = fuel(weight),
        tmp = totalFuel;
    while ((fuelWeight = fuel(tmp)) > 0) {
        totalFuel += fuelWeight;
        tmp = fuelWeight;
    }
    return totalFuel;
}

const test = (input, expected) => {
    const actual = fuelCal(input);
    if (expected !== actual) {
        throw new Error(`Expected [${expected}] but got [${actual}]`);
    }
}

test(14, 2)
test(1969, 966)
test(100756, 50346)

console.log("total: ", inputs.reduce((prev, current) => prev + fuelCal(current), 0))