fix: Fix grammars default value to null

src/SpeechRecognitionWrapper.js

@@ -50,6 +50,16 @@ class SpeechRecognitionWrapper {
 		this._instance = new SpeechRecognition()
 		this._listeners = {}
 
+		if(!!options && !options.grammars) {
+			const SpeechGrammarList =
+				window.SpeechGrammarList ||
+				window.webkitSpeechGrammarList ||
+				window.mozSpeechGrammarList ||
+				window.msSpeechGrammarList ||
+				{}
+			this._instance.grammars = new SpeechGrammarList()
+		}
+
 		Object.entries({ ...SpeechRecognitionWrapper.defaultOptions, ...(options || {}) }).forEach(
 			([key, value]) => (this._instance[key] = value)
 		)

src/__tests__/Vocal.test.js

@@ -30,6 +30,9 @@ describe('Vocal', () => {
 			getUserMedia: jest.fn().mockResolvedValue('foo'),
 		}))
 		global.navigator.mediaDevices = new MediaDevices()
+		global.SpeechGrammarList = jest.fn(() => ({
+			length: 0,
+		}))
 		global.SpeechRecognition = jest.fn(() => {
 			const handlers = {}
 			return {
@@ -71,6 +74,7 @@ describe('Vocal', () => {
 		global.PermissionStatus.mockReset()
 		global.Permissions.mockReset()
 		global.MediaDevices.mockReset()
+		global.SpeechGrammarList.mockReset()
 		global.SpeechRecognition.mockReset()
 	})