Get unstuck

Hint 1: Use artifact evidence as the left side

The required set is shipped minus documented.

Hint 2: A different version is a different identity

Compare the full supplied package URL. Do not strip versions or lowercase case-sensitive components.

Reveal the reference patch and explanation
Fixedinventory.mjsJavaScript
export function missingComponents(shipped, documented) {
  const known = new Set(documented);
  return [...new Set(shipped.filter(id => !known.has(id)))].sort();
}

For shipped=[app@1,parser@2] and documented=[app@1], the missing set is [parser@2]. Documenting parser@1 does not cover parser@2. Repeated shipped observations produce one omission, and z-helper/a-helper results sort to a-helper then z-helper. A development-only documented package is an extra record, not a missing shipped component. An empty result means only that these two supplied sets have no omissions; it does not establish how completely shipped was discovered.

Compare it with your own fix, then rerun the tests. The editor is not changed when you open this explanation.

Inspect the actual test harness

The browser and the lab download run the same cases, including cases that catch common wrong fixes, such as comparing with one fixture value instead of the real rule. The download includes the complete test adapter and cryptographic fixtures.

Download cases.mjs
How the browser sandbox runs your code

Your code runs in QuickJS 2025-09-13 (quickjs-emscripten 0.32.0) inside a Web Worker, isolated from the page, with a 32 MiB memory limit and a 2.5-second time limit. The test cases and the pass or fail verdict run outside that sandbox, so changing built-ins such as Array.prototype.push cannot change the result. The lab download runs the same cases under Node.js, where your code runs directly.

The same as in current Node.js:

  • ES2025 syntax and built-ins, including Set methods such as intersection, iterator helpers, Promise.try, RegExp.escape and the RegExp v flag

Added to the sandbox so that it behaves like Node.js:

  • structuredClone, Array.fromAsync, queueMicrotask, atob and btoa
  • URL and URLSearchParams, parsed by your browser’s own URL implementation
  • TextEncoder and TextDecoder for UTF-8
  • Intl.Collator and a locale-aware String.prototype.localeCompare
  • console.log and related methods, whose output appears with your results

Not available in the browser sandbox:

  • Timers (setTimeout, setInterval), fetch and other network or storage APIs; the exercises are deterministic and offline
  • Node.js modules and globals: import, require, process and Buffer
  • Web Crypto (crypto.getRandomValues, crypto.subtle); each workshop supplies the cryptographic operations it needs
  • Intl other than Collator: toLocaleString and toLocaleDateString ignore the locale, so numbers have no digit grouping and dates use one fixed format in the device’s time zone
  • using declarations, Symbol.dispose and DisposableStack (explicit resource management)
  • Uint8Array.fromBase64 and toBase64, JSON.rawJSON, Atomics and Error.captureStackTrace

Use the lesson in your own system

These are supplied inventory fixtures, not a package scanner. Full package URL normalization, license/vulnerability analysis and artifact discovery belong to dedicated tools. Real completeness claims need evidence of how the artifact inventory was produced.

Your next task: Which build step can reveal vendored or bundled packages that never appear in your manifest?

CycloneDX specification

Related guide: Generate an SBOM for the software you actually release