Automatically choose the latest versions of all packages when running yarn --flat

yarn-flat-auto.js

#!/usr/bin/env node
# run this before using: yarn add --dev node-pty semver

const os = require("os")
const pty = require("node-pty")

const semver = require("semver")

function semverComparator(a, b) {
  if (semver.lt(a, b)) {
    return -1
  } else if (semver.gt(a, b)) {
    return 1
  } else {
    return 0
  }
}

const proc = pty.spawn("yarn", ["install", "--flat"], {
  name: "xterm-color",
  cols: 80,
  rows: 30,
  env: process.env,
})

let buff = ""

proc.on("data", function(data) {
  buff += data.toString()
  if (buff.match(/Answer\?:/g)) {
    const packageName = buff.match(/suitable version for "(\S+)"/)[1]
    const versions = buff
      .split(/\r?\n/g)
      .filter(line => line.match("which resolved to"))
      .map(line => line.match(/"(\S+)"$/)[1])
    const sorted = versions.slice(0).sort(semverComparator)
    const highestVersion = sorted[sorted.length - 1]
    const choice = versions.indexOf(highestVersion) + 1
    console.log(`Choosing ${packageName}@${highestVersion}`)
    proc.write(choice.toString() + "\r\n")
    buff = ""
  }
})

proc.on("error", err => {
  console.error(err)
})

I made some changes to get it working on my Windows environment with a large project.

const pty = require("node-pty");
const semver = require("semver");

function semverComparator(a, b) {
  if (semver.lt(a, b)) {
    return -1;
  } else if (semver.gt(a, b)) {
    return 1;
  } else {
    return 0;
  }
}

const proc = pty.spawn(`yarn${process.platform === "win32" ? ".cmd" : ""}`, ["install", "--flat"], {
  name: "xterm-color",
  cols: 8000,
  rows: 9001,
  env: process.env,
});

let buff = "";

function onAnswer() {
  const packageName = buff.match(/suitable version for "(\S+)"/)[1];
  const versions = buff
    .split(/\r?\n/g)
    .filter((line) => line.match("which resolved to"))
    .map((line) => line.match(/o "(\S+)"/)[1]);
  if (!versions || versions.length < 2) {
    throw new Error("No versions found!");
  }
  const sorted = versions.slice(0).sort(semverComparator);
  const highestVersion = sorted[sorted.length - 1];
  const choice = versions.indexOf(highestVersion) + 1;
  console.log(`Choosing ${packageName}@${highestVersion}`);
  buff = "";
  proc.write(choice.toString() + "\r\n");
}

let receivedInput = false;
let outputMode = false;
let answerFound = false;
let idlingTimeout;
proc.onData(function (data) {
  if (outputMode) {
    console.log(data);
  } else {
    buff += data.toString();
    if (buff.match(/Answer\?:/g)) {
      if (!answerFound) {
        answerFound = true;
        console.clear();
      }
      receivedInput = true;
      if (idlingTimeout) {
        clearTimeout(idlingTimeout);
      }
      idlingTimeout = setTimeout(onAnswer, 500);
    } else if (buff.match("Fetching packages")) {
      outputMode = true;
    } else if (!answerFound) {
      console.log(data);
    }
  }
});

proc.on("error", (err) => {
  console.error(err);
});

proc.onExit(function (_e) {
  process.exit(1);
});