// Containment proof for the TypeScript engine: this page imports the host tagged
// ?nib-selftest=ts-engine-off — the query rides to the kernel worker, whose strip
// init fails (as it would under a CSP without 'wasm-unsafe-eval'; this Chromium
// does not bind that directive to module workers, so the genuine failure cannot be
// staged). The kernel must still boot — plain JS keeps running — while every .ts
// load fails with the named ERR_NIB_TS_ENGINE.
import { boot } from "@nibling/kernel-off";

const out = document.getElementById("out");
const errEl = document.getElementById("err");
const exitEl = document.getElementById("exit");
const dec = new TextDecoder();

try {
  const runtime = await boot();
  runtime.writeTree({
    "/app/plain.js": "module.exports = 'plain js still runs';\n",
    "/app/js-main.cjs": "const tag = require('./plain.js');\nconsole.log(tag);\n",
    "/app/stripped.ts": "const tag: string = 'never';\nmodule.exports = tag;\n",
    "/app/ts-main.cjs": "const t = require('./stripped.ts');\nconsole.log(t);\n",
  });

  const codes = [];
  for (const plan of [
    { label: "js", entry: "/app/js-main.cjs" },
    { label: "ts", entry: "/app/ts-main.cjs" },
  ]) {
    const proc = runtime.exec(plan.entry);
    const drained = Promise.all([
      proc.stdout.pipeTo(new WritableStream({
        write: (c) => { out.textContent += dec.decode(c); },
      })),
      proc.stderr.pipeTo(new WritableStream({
        write: (c) => { errEl.textContent += dec.decode(c); },
      })),
    ]);
    const code = await proc.exited;
    await drained;
    codes.push(`${plan.label}=${code}`);
  }
  exitEl.textContent = codes.join(" ");
} catch (e) {
  errEl.textContent = "BOOT FAILED: " + (e?.message ?? String(e));
  exitEl.textContent = "?";
}