Function serializeEnvelope

packages/core/src/utils/envelope.ts:92–127

(envelope: Envelope)

 * Serializes an envelope.
 */
export function serializeEnvelope(envelope: Envelope): string | Uint8Array {
  const [envHeaders, items] = envelope;
  // Initially we construct our envelope as a string and only convert to binary chunks if we encounter binary data
  let parts: string | Uint8Array[] = JSON.stringify(envHeaders);

  function append(next: string | Uint8Array): void {
    if (typeof parts === 'string') {
      parts = typeof next === 'string' ? parts + next : [encodeUTF8(parts), next];
    } else {
      parts.push(typeof next === 'string' ? encodeUTF8(next) : next);
    }
  }

  for (const item of items) {
    const [itemHeaders, payload] = item;

    append(`\n${JSON.stringify(itemHeaders)}\n`);

    if (typeof payload === 'string' || payload instanceof Uint8Array) {
      append(payload);
    } else {
      let stringifiedPayload: string;
      try {
        stringifiedPayload = JSON.stringify(payload);
      } catch {
        // In case, despite all our efforts to keep `payload` circular-dependency-free, `JSON.stringify()` still
        // fails, we try again after normalizing it again with infinite normalization depth. This of course has a
        // performance impact but in this case a performance hit is better than throwing.
        stringifiedPayload = JSON.stringify(normalize(payload));
      }
      append(stringifiedPayload);
    }
  }

  return typeof parts === 'string' ? parts : concatBuffers(parts);
}

function concatBuffers(buffers: Uint8Array[]): Uint8Array {
  const totalLength = buffers.reduce((acc, buf) => acc + buf.length, 0);