meteor/v3-docs/docs/generators/changelog/script.js

const _fs = require("fs");
const fs = _fs.promises;
function getPackageVersion(packageName) {
  function getFile(path) {
    try {
      const data = _fs.readFileSync(path, "utf8");
      return [data, null];
    } catch (e) {
      console.error(e);
      return ["", e];
    }
  }

  const [code, error] = getFile(`../../packages/${packageName}/package.js`);
  if (error) return "";
  for (const line of code.split(/\n/)) {
    // verify if the line has a version
    if (!line.includes("version:")) continue;

    //Package.describe({
    //   summary: 'some description.',
    //   version: '1.2.3' <--- this is the line we want, we assure that it has a version in the previous if
    //});
    const [_, versionValue] = line.split(":");
    if (!versionValue) continue;
    const removeQuotes = (v) =>
      v.trim().replace(",", "").replace(/'/g, "").replace(/"/g, "");
    if (versionValue.includes("-"))
      return removeQuotes(versionValue.split("-")[0]);
    return removeQuotes(versionValue);
  }
}

exports.generateChangelog = async () => {
  try {
    console.log("started concatenating files");
    const files = await fs.readdir("./generators/changelog/versions", "utf8");
    const filesStream = files
      .map((file) => {
        console.log(`reading file: ${file}`);
        return {
          fileName: file,
          buf: fs.readFile(`./generators/changelog/versions/${file}`, "utf8"),
        };
      })
      .map(async ({ buf, fileName }, index) => {
        // first file we don't do anything
        // Big file and does not follow the new standard
        if (index === 0) return buf;
        const content = (await buf).toString();
        /**
         * @type {Set<string>}
         */
        const contribuitors = new Set();

        // DSL Replacers
        // [PR #123] -> [PR #123](https://github.com/meteor/meteor/pull/123)
        // [GH meteor/meteor] -> [meteor/meteor](https://github.com/meteor/meteor)
        // package-name@get-version -> package-name@1.3.3

        const file = content
          .replace(
            /\[PR #(\d+)\]/g,
            (_, number) =>
              `[PR](https://github.com/meteor/meteor/pull/${number})`
          )
          .replace(/\[GH ([^\]]+)\]/g, (_, name) => {
            contribuitors.add(name);
            return `[${name}](https://github.com/${name})`;
          })
          .replace(
            /([a-z0-9-]+)@get-version/g,
            (_, name) => `${name}@${getPackageVersion(name)}`
          );

        // already have the contribuitors thanks in the file
        if (
          file.includes("#### Special thanks to") ||
          file.includes("[//]: # (Do not edit this file by hand.)")
        )
          return file;

        // add the contribuitors
        const contribuitorsList = Array.from(contribuitors)
          .map((name) => `- [@${name}](https://github.com/${name}).`)
          .join("\n");

        const doneFile = `${file}\n\n#### Special thanks to\n\n${contribuitorsList}\n\n`;

        //SIDE EFFECTS
        // so that this is not ran every time, we will update the last file.
        // this is for the expensive part of the script
        if (index === files.length - 2)
          await fs.writeFile(
            `./generators/changelog/versions/${fileName}`,
            doneFile
          );
        return doneFile;
      })
      .reverse();
    console.log("Giving some touches to the files");
    const filesContent = await Promise.all(filesStream);
    await fs.writeFile("./history.md", filesContent.join(""));
    console.log("Finished :)");
  } catch (e) {
    console.log(e);
  }
};