Fixes RST headline lenghts

headline-fixer.mjs

import glob from "glob";
import { promises as fs } from "fs";

let changed = false;

Promise.all(
  glob.sync("./**/*.rst").map((s) =>
    fs.readFile(s, "utf-8").then((rst) => {
      const lines = rst.split("\n");
      lines.forEach((line, n) => {
        const m = /^[#\*=-]+$/.exec(line);
        if (m) {
          lines[n] = m[0][0].repeat(lines[n - 1].length);
        }
      });
      const updated = lines.join("\n");
      if (updated.localeCompare(rst) !== 0) {
        changed = true;
        console.error(`Rewritten ${s}`);
        return fs.writeFile(s, updated, "utf-8");
      }
    })
  )
).then(() => {
  if (changed) {
    process.exit(1);
  }
});