index.js

const express = require("express");
const { mf2 } = require("microformats-parser");
const pkg = require("./package.json");
const app = express();
const port = process.env.PORT || 9000;

function getDependencyVersion(dependencyName) {
  const fs = require("fs");
  const lockfile = require("@yarnpkg/lockfile");
  const parsed = lockfile.parse(fs.readFileSync("./yarn.lock", "utf-8"));
  if (parsed.type !== "success") return "unknown";
  const dependency =
    parsed.object[`${dependencyName}@${pkg.dependencies[dependencyName]}`];
  if (dependency === undefined) return "unknown";
  return dependency.version;
}
const mf2version = getDependencyVersion("microformats-parser");

function readExperimental(params) {
  const experimental = {};
  for (const flag of ["lang", "textContent", "metaformats"]) {
    if (params[flag] === "true") experimental[flag] = true;
  }
  return Object.keys(experimental).length > 0 ? { experimental } : {};
}

function htmlToMf2(url, html, experimental, res) {
  try {
    const body = mf2(html, { baseUrl: url, ...experimental });
    res
      .header("content-type", "application/json; charset=UTF-8")
      .send(JSON.stringify(body, null, 2));
  } catch (err) {
    res
      .header("content-type", "application/json; charset=UTF-8")
      .status(500)
      .send(JSON.stringify({ error: err.message }, null, 2));
  }
}

app.set("view engine", "ejs");
app.use(express.static("public"));
app.get("/", async (req, res) => {
  if (req.query.url) {
    const url = req.query.url;
    const experimental = readExperimental(req.query);
    await fetch(url, {
      headers: {
        accept: "text/html, text/mf2+html",
      },
      method: "GET",
    }).then(async (response) => {
      const html = await response.text();
      htmlToMf2(url, html, experimental, res);
    });
  } else {
    res.render("index.html.ejs", {
      site_version: pkg.version,
      mf2_version: mf2version,
    });
  }
});
app.post("/", express.urlencoded({ extended: false }), (req, res) => {
  htmlToMf2(req.body.url, req.body.html, {}, res);
});

app.listen(port, () => {
  console.log(`Example app listening on port ${port}`);
});