bun.sh/test/js/node/cluster/upstream/parallel/test-cluster-fork-windowsHide.js

"use strict";
const common = require("../common");
if (common.isWindows) return; // TODO: bun
const assert = require("assert");
const child_process = require("child_process");
const cluster = require("cluster");

if (!process.argv[2]) {
  // It seems Windows only allocate new console window for
  // attaching processes spawned by detached processes. i.e.
  // - If process D is spawned by process C with `detached: true`,
  //   and process W is spawned by process D with `detached: false`,
  //   W will get a new black console window popped up.
  // - If D is spawned by C with `detached: false` or W is spawned
  //   by D with `detached: true`, no console window will pop up for W.
  //
  // So, we have to spawn a detached process first to run the actual test.
  const primary = child_process.spawn(process.argv[0], [process.argv[1], "--cluster"], {
    detached: true,
    stdio: ["ignore", "ignore", "ignore", "ipc"],
  });

  const messageHandlers = {
    workerOnline: common.mustCall(),
    mainWindowHandle: common.mustCall(msg => {
      assert.match(msg.value, /0\s*/);
    }),
    workerExit: common.mustCall(msg => {
      assert.strictEqual(msg.code, 0);
      assert.strictEqual(msg.signal, null);
    }),
  };

  primary.on("message", msg => {
    const handler = messageHandlers[msg.type];
    assert.ok(handler);
    handler(msg);
  });

  primary.on(
    "exit",
    common.mustCall((code, signal) => {
      assert.strictEqual(code, 0);
      assert.strictEqual(signal, null);
    }),
  );
} else if (cluster.isPrimary) {
  cluster.setupPrimary({
    silent: true,
    windowsHide: true,
  });

  const worker = cluster.fork();
  worker.on("exit", (code, signal) => {
    process.send({ type: "workerExit", code: code, signal: signal });
  });

  worker.on("online", msg => {
    process.send({ type: "workerOnline" });

    let output = "0";
    if (process.platform === "win32") {
      output = child_process.execSync(
        "powershell -NoProfile -c " + `"(Get-Process -Id ${worker.process.pid}).MainWindowHandle"`,
        { windowsHide: true, encoding: "utf8" },
      );
    }

    process.send({ type: "mainWindowHandle", value: output });
    worker.send("shutdown");
  });
} else {
  cluster.worker.on("message", msg => {
    cluster.worker.disconnect();
  });
}