Function isAwaitInUserspace

packages/react-server/src/ReactFlightServer.js:347–373

(
  request: Request,
  stack: ReactStackTrace,
)

}

export function isAwaitInUserspace(
  request: Request,
  stack: ReactStackTrace,
): boolean {
  let firstFrame = 0;
  while (
    stack.length > firstFrame &&
    isPromiseAwaitInternal(stack[firstFrame][1], stack[firstFrame][0])
  ) {
    // Skip the internal frame that awaits itself.
    firstFrame++;
  }
  if (stack.length > firstFrame) {
    // Check if the very first stack frame that awaited this Promise was in user space.
    // TODO: This doesn't take into account wrapper functions such as our fake .then()
    // in FlightClient which will always be considered third party awaits if you call
    // .then directly.
    const filterStackFrame = request.filterStackFrame;
    const callsite = stack[firstFrame];
    const functionName = callsite[0];
    const url = devirtualizeURL(callsite[1]);
    const lineNumber = callsite[2];
    const columnNumber = callsite[3];
    return filterStackFrame(url, functionName, lineNumber, columnNumber);
  }
  return false;
}

initAsyncDebugInfo();