@thi.ng/server/utils/formdata.js

Minimal HTTP server with declarative routing, static file serving and freely extensible via pre/post interceptors

import { isArray, isProtoPath } from "@thi.ng/checks";
import { illegalArgs } from "@thi.ng/errors";
import { setInUnsafe, updateInUnsafe } from "@thi.ng/paths";
const parseSearchParams = (params) => {
  let acc = {};
  for (const [k, v] of params) {
    if (k.includes("[")) acc = parseObjectVal(acc, k, v);
    else if (!isProtoPath(k)) acc[k] = v;
  }
  return acc;
};
const parseQuerystring = (url) => {
  const idx = url.indexOf("?");
  return idx >= 0 ? parseFormData(url.substring(idx + 1)) : {};
};
const parseRequestFormData = async (req) => {
  let body = "";
  for await (let chunk of req) body += chunk.toString();
  return parseFormData(body);
};
const parseFormData = (body) => body.split("&").reduce((acc, x) => {
  x = decodeURIComponent(x.replace(/\+/g, " "));
  const idx = x.indexOf("=");
  if (idx < 1) return acc;
  const k = x.substring(0, idx);
  const v = x.substring(idx + 1);
  if (k.includes("[")) return parseObjectVal(acc, k, v);
  if (!isProtoPath(k)) acc[k] = v;
  return acc;
}, {});
const parseObjectVal = (acc, key, val) => {
  const parts = key.split("[");
  if (!parts[0]) __illegal(key);
  const path = [parts[0]];
  for (let i = 1, n = parts.length - 1; i <= n; i++) {
    const p = parts[i];
    if (p === "]") {
      if (i < n) __illegal(key);
      return !isProtoPath(path) ? updateInUnsafe(
        acc,
        path,
        (curr) => isArray(curr) ? [...curr, val] : [val]
      ) : acc;
    }
    const idx = p.indexOf("]");
    if (idx < 0 || idx < p.length - 1) __illegal(key);
    path.push(p.substring(0, p.length - 1));
  }
  return !isProtoPath(path) ? setInUnsafe(acc, path, val) : acc;
};
const __illegal = (key) => illegalArgs("invalid form param: " + key);
export {
  parseFormData,
  parseQuerystring,
  parseRequestFormData,
  parseSearchParams
};