nstdlib-nightly/lib/internal/test_runner/reporter/v8-serializer.mjs

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

// Source: https://github.com/nodejs/node/blob/65eff1eb/lib/internal/test_runner/reporter/v8-serializer.js

import { DefaultSerializer } from "nstdlib/lib/v8";
import { Buffer } from "nstdlib/lib/buffer";
import { serializeError } from "nstdlib/lib/internal/error_serdes";

export default (async function* v8Reporter(source) {
  const serializer = new DefaultSerializer();
  serializer.writeHeader();
  const headerLength = TypedArrayPrototypeGetLength(serializer.releaseBuffer());

  for await (const item of source) {
    const originalError = item.data.details?.error;
    if (originalError) {
      // Error is overriden with a serialized version, so that it can be
      // deserialized in the parent process.
      // Error is restored after serialization.
      item.data.details.error = serializeError(originalError);
    }
    serializer.writeHeader();
    // Add 4 bytes, to later populate with message length
    serializer.writeRawBytes(Buffer.allocUnsafe(4));
    serializer.writeHeader();
    serializer.writeValue(item);

    if (originalError) {
      item.data.details.error = originalError;
    }

    const serializedMessage = serializer.releaseBuffer();
    const serializedMessageLength =
      serializedMessage.length - (4 + headerLength);

    serializedMessage.set(
      [
        (serializedMessageLength >> 24) & 0xff,
        (serializedMessageLength >> 16) & 0xff,
        (serializedMessageLength >> 8) & 0xff,
        serializedMessageLength & 0xff,
      ],
      headerLength,
    );
    yield serializedMessage;
  }
});