Function createRecognizer

packages/@react-spectrum/ai/src/useVoiceInput.ts:173–228

(
  ctor: SpeechRecognitionConstructor,
  lang: string,
  setup: RecognizerSetup
)

 * previous session can't wipe out a newly-started recognizer.
 */
const createRecognizer = (
  ctor: SpeechRecognitionConstructor,
  lang: string,
  setup: RecognizerSetup
): SpeechRecognition => {
  const recognition = new ctor();
  recognition.continuous = true;
  recognition.interimResults = true;
  recognition.lang = lang;

  // Ignore events from a session that is no longer the active recognizer (e.g. a
  // late onend/onerror after a new session started), so they can't flip the
  // listening state, surface a st ale error, or clear a newer recognizer.
  const isActive = () => setup.recognitionRef.current === recognition;

  recognition.onstart = () => {
    setup.setListening(true);
    setup.onListeningChange(true);
  };
  recognition.onresult = event => {
    if (!isActive()) {
      return;
    }
    const {interim, final} = readTranscript(event);
    if (final) {
      setup.appendFinal(final);
    }
    setup.setInterim(interim);
  };
  recognition.onerror = event => {
    if (!isActive()) {
      return;
    }
    const code = mapErrorCode(event.error);
    if (code) {
      setup.setError(code);
      setup.onError(code);
    }
    setup.setListening(false);
    setup.onListeningChange(false);
    setup.setInterim('');
    // Clear so the next press starts a fresh session instead of calling stop().
    setup.recognitionRef.current = null;
  };
  recognition.onend = () => {
    if (!isActive()) {
      return;
    }
    setup.setListening(false);
    setup.onListeningChange(false);
    setup.setInterim('');
    setup.recognitionRef.current = null;
  };

  return recognition;
};

export const useVoiceInput = (options: VoiceInputProps): VoiceInputResult => {