registerWebServiceExtension function Null safety
The web implementation of registerWebServiceExtension.
Adds a hidden window.$flutterDriver
JavaScript function that's called by
FlutterWebDriver
to fulfill FlutterDriver commands.
See also:
_extension_io.dart
, which has the dart:io implementation
Implementation
void registerWebServiceExtension(Future<Map<String, dynamic>> Function(Map<String, String>) callback) {
// Define the result variable because packages/flutter_driver/lib/src/driver/web_driver.dart
// checks for this value to become non-null when waiting for the result. If this value is
// undefined at the time of the check, WebDriver throws an exception.
context[r'$flutterDriverResult'] = null;
js_util.setProperty(html.window, r'$flutterDriver', allowInterop((dynamic message) async {
try {
final Map<String, dynamic> messageJson = jsonDecode(message as String) as Map<String, dynamic>;
final Map<String, String> params = messageJson.cast<String, String>();
final Map<String, dynamic> result = await callback(params);
context[r'$flutterDriverResult'] = json.encode(result);
} catch (error, stackTrace) {
// Encode the error in the same format the FlutterDriver extension uses.
// See //packages/flutter_driver/lib/src/extension/extension.dart
context[r'$flutterDriverResult'] = json.encode(<String, dynamic>{
'isError': true,
'response': '$error\n$stackTrace',
});
}
}));
}