registerPendingOperation method

void Function() registerPendingOperation(String description)

Registers a new pending operation and returns a new function that can be used to signal that the pending operation has completed.

The returned function is safe to be used before return statements.

Implementation

void Function() registerPendingOperation(String description) {
  _pendingCalls++;
  _ongoingOperations.add(description);

  final completer = Completer<void>();

  _knownCallsHandled = [..._knownCallsHandled, completer.future];

  // Guard that the `done` callback runs only once
  var done = false;

  return () => Timer.run(
        () {
          if (done) {
            assert(
              false,
              'Tried running completer function twice. Operation: $description',
            );
            return;
          }

          done = true;

          _ongoingOperations.remove(description);
          _pendingCalls--;
          completer.complete();
        },
      );
}