Extracts HTTP headers from curl command-line args

curl-to-headers.ts

// convert headers object to object
Array.from(headers).reduce((a: { [k: string]: string }, kv) => (a[kv[0]] = kv[1], a), {})

// parse curl-compatible -H arguments in command-line into object
function seq(first: number, last: number): number[] {
  if (first < last) {
    return [first].concat(seq(first + 1, last));
  } else if (first > last) {
    return [last].concat(seq(first, last - 1));
  } else {
    return [first];
  }
}

const headers = seq(2, process.argv.length - 1)
  .filter(n => process.argv[n] === "-H")
  .map(n => process.argv[n + 1])
  .map(s => {
    const [h, ...v] = s.split(": ");
    return [h, v.join("")];
  })
  .reduce((a: {[key: string]: any}, kv) => {
    a[kv[0]] = kv[1];
    return a;
  }, {});