nstdlib-nightly/lib/sea.mjs

Node.js standard library converted to runtime-agnostic ES modules.

// Source: https://github.com/nodejs/node/blob/65eff1eb/lib/sea.js

import { isSea, getAsset as getAssetInternal } from "nstdlib/stub/binding/sea";
import { TextDecoder } from "nstdlib/lib/internal/encoding";
import { validateString } from "nstdlib/lib/internal/validators";
import { codes as __codes__ } from "nstdlib/lib/internal/errors";
import { Blob } from "nstdlib/lib/internal/blob";

const {
  ERR_NOT_IN_SINGLE_EXECUTABLE_APPLICATION,
  ERR_SINGLE_EXECUTABLE_APPLICATION_ASSET_NOT_FOUND,
} = __codes__;

/**
 * Look for the asset in the injected SEA blob using the key. If
 * no matching asset is found an error is thrown. The returned
 * ArrayBuffer should not be mutated or otherwise the process
 * can crash due to access violation.
 * @param {string} key
 * @returns {ArrayBuffer}
 */
function getRawAsset(key) {
  validateString(key, "key");

  if (!isSea()) {
    throw new ERR_NOT_IN_SINGLE_EXECUTABLE_APPLICATION();
  }

  const asset = getAssetInternal(key);
  if (asset === undefined) {
    throw new ERR_SINGLE_EXECUTABLE_APPLICATION_ASSET_NOT_FOUND(key);
  }
  return asset;
}

/**
 * Look for the asset in the injected SEA blob using the key. If the
 * encoding is specified, return a string decoded from it by TextDecoder,
 * otherwise return *a copy* of the original data in an ArrayBuffer. If
 * no matching asset is found an error is thrown.
 * @param {string} key
 * @param {string|undefined} encoding
 * @returns {string|ArrayBuffer}
 */
function getAsset(key, encoding) {
  if (encoding !== undefined) {
    validateString(encoding, "encoding");
  }
  const asset = getRawAsset(key);
  if (encoding === undefined) {
    return ArrayBuffer.prototype.slice.call(asset);
  }
  const decoder = new TextDecoder(encoding);
  return decoder.decode(asset);
}

/**
 * Look for the asset in the injected SEA blob using the key. If
 * no matching asset is found an error is thrown. The data is returned
 * in a Blob. If no matching asset is found an error is thrown.
 * @param {string} key
 * @param {ConstructorParameters<Blob>[1]} [options]
 * @returns {Blob}
 */
function getAssetAsBlob(key, options) {
  const asset = getRawAsset(key);
  return new Blob([asset], options);
}

export { isSea };
export { getAsset };
export { getRawAsset };
export { getAssetAsBlob };