@prairielearn/utils

Various shared utilities.

Usage

extractZipArchive()

Node-only zip extraction with entry-count, expanded-size, and symlink validation is available from the zip subpath.

import { ZipArchiveValidationError, extractZipArchive } from '@prairielearn/utils/zip';

try {
  await extractZipArchive({
    archivePath: '/tmp/upload.zip',
    destinationDir: '/tmp/extracted',
    maxEntries: 10_000,
    maxExtractedBytes: 500 * 1024 * 1024,
  });
} catch (err) {
  if (err instanceof ZipArchiveValidationError) {
    // Use err.code for control flow or err.message for user-facing errors.
  }
  throw err;
}

Callers must specify both maxEntries and maxExtractedBytes; pass null for either value to explicitly disable that limit.

withResolvers()

A tiny utility for creating Promises with exposed resolve and reject methods, similar to Promise.withResolvers().

Once Promise.withResolvers() is widely supported in browsers, users of this package should switch to it.

import { withResolvers } from '@prairielearn/utils';

const { promise, resolve, reject } = withResolvers<number>();

setTimeout(() => resolve(42), 100);

promise.then((value) => {
  console.log(value); // 42
});