Async patterns

The native addon executes compression and decompression on libuv worker threads, so calls don't block the event loop. The TypeScript API is synchronous in shape (it doesn't return Promises), but the underlying work runs in parallel with whatever else your event loop is doing.

For Promise-style parallelism, wrap the synchronous calls in Promise.all across an array of files:

import { read } from "mscompress";

const files = ["a.mzML", "b.mzML", "c.mzML"];
await Promise.all(files.map(async path => {
  const f = read(path);
  try {
    f.compress(path.replace(".mzML", ".msz"));
  } finally {
    f.close();
  }
}));

Resource cleanup

Always call close(). If your TypeScript target supports using declarations (ES2024+), prefer them:

using f = read("data.msz");
// f.close() runs at scope exit

Otherwise, use try { ... } finally { f.close(); }.