web implementation

packages/google_maps_flutter/google_maps_flutter_web/example/integration_test/google_maps_controller_test.dart

@@ -444,6 +444,46 @@ void main() {
           expect(capturedOptions!.zoom, 12);
           expect(capturedOptions!.center, isNotNull);
         });
+
+        testWidgets('translates style option', (WidgetTester tester) async {
+          const String style = '''
+[{
+  "featureType": "poi.park",
+  "elementType": "labels.text.fill",
+  "stylers": [{"color": "#6b9a76"}]
+}]''';
+          controller = createController(
+              mapConfiguration: const MapConfiguration(style: style));
+          controller.debugSetOverrides(
+              createMap: (_, gmaps.MapOptions options) {
+            capturedOptions = options;
+            return map;
+          });
+
+          controller.init();
+
+          expect(capturedOptions, isNotNull);
+          expect(capturedOptions!.styles?.length, 1);
+        });
+
+        testWidgets('stores style errors for later querying',
+            (WidgetTester tester) async {
+          controller = createController(
+              mapConfiguration: const MapConfiguration(
+                  style: '[[invalid style', zoomControlsEnabled: true));
+          controller.debugSetOverrides(
+              createMap: (_, gmaps.MapOptions options) {
+            capturedOptions = options;
+            return map;
+          });
+
+          controller.init();
+
+          expect(controller.lastStyleError, isNotNull);
+          // Style failures should not prevent other options from being set.
+          expect(capturedOptions, isNotNull);
+          expect(capturedOptions!.zoomControl, true);
+        });
       });
 
       group('Traffic Layer', () {
@@ -481,7 +521,7 @@ void main() {
           ..init();
       });
 
-      group('updateRawOptions', () {
+      group('updateMapConfiguration', () {
         testWidgets('can update `options`', (WidgetTester tester) async {
           controller.updateMapConfiguration(const MapConfiguration(
             mapType: MapType.satellite,
@@ -505,6 +545,27 @@ void main() {
 
           expect(controller.trafficLayer, isNull);
         });
+
+        testWidgets('can update style', (WidgetTester tester) async {
+          const String style = '''
+[{
+  "featureType": "poi.park",
+  "elementType": "labels.text.fill",
+  "stylers": [{"color": "#6b9a76"}]
+}]''';
+          controller
+              .updateMapConfiguration(const MapConfiguration(style: style));
+
+          expect(controller.styles.length, 1);
+        });
+
+        testWidgets('can update style', (WidgetTester tester) async {
+          controller.updateMapConfiguration(
+              const MapConfiguration(style: '[[[invalid style'));
+
+          expect(controller.styles, isEmpty);
+          expect(controller.lastStyleError, isNotNull);
+        });
       });
 
       group('viewport getters', () {

packages/google_maps_flutter/google_maps_flutter_web/lib/src/convert.dart

@@ -80,6 +80,7 @@ gmaps.MapOptions _configurationAndStyleToGmapsOptions(
   options.fullscreenControl = false;
   options.streetViewControl = false;
 
+  // See updateMapConfiguration for why this is not using configuration.style.
   options.styles = styles;
 
   options.mapId = configuration.cloudMapId;

packages/google_maps_flutter/google_maps_flutter_web/lib/src/google_maps_controller.dart

@@ -32,6 +32,7 @@ class GoogleMapController {
     _polylinesController = PolylinesController(stream: _streamController);
     _markersController = MarkersController(stream: _streamController);
     _tileOverlaysController = TileOverlaysController();
+    _updateStylesFromConfiguration(mapConfiguration);
 
     // Register the view factory that will hold the `_div` that holds the map in the DOM.
     // The `_div` needs to be created outside of the ViewFactory (and cached!) so we can
@@ -60,6 +61,8 @@ class GoogleMapController {
   // Caching this allows us to re-create the map faithfully when needed.
   MapConfiguration _lastMapConfiguration = const MapConfiguration();
   List<gmaps.MapTypeStyle> _lastStyles = const <gmaps.MapTypeStyle>[];
+  // The last error resulting from providing a map style, if any.
+  String? _lastStyleError;
 
   /// Configuration accessor for the [GoogleMapsInspectorWeb].
   ///
@@ -279,15 +282,36 @@ class GoogleMapController {
     return _lastMapConfiguration;
   }
 
+  // TODO(stuartmorgan): Refactor so that _lastMapConfiguration.style is the
+  // source of truth for style info. Currently it's tracked and handled
+  // separately since style didn't used to be part of the configuration.
+  List<gmaps.MapTypeStyle> _updateStylesFromConfiguration(
+      MapConfiguration update) {
+    if (update.style != null) {
+      // Provide async access to the error rather than throwing, to match the
+      // behavior of other platforms where there's no mechanism to return errors
+      // from configuration updates.
+      try {
+        _lastStyles = _mapStyles(update.style);
+        _lastStyleError = null;
+      } on MapStyleException catch (e) {
+        _lastStyleError = e.cause;
+      }
+    }
+    return _lastStyles;
+  }
+
   /// Updates the map options from a [MapConfiguration].
   ///
   /// This method converts the map into the proper [gmaps.MapOptions].
   void updateMapConfiguration(MapConfiguration update) {
     assert(_googleMap != null, 'Cannot update options on a null map.');
 
+    final List<gmaps.MapTypeStyle> styles =
+        _updateStylesFromConfiguration(update);
     final MapConfiguration newConfiguration = _mergeConfigurations(update);
     final gmaps.MapOptions newOptions =
-        _configurationAndStyleToGmapsOptions(newConfiguration, _lastStyles);
+        _configurationAndStyleToGmapsOptions(newConfiguration, styles);
 
     _setOptions(newOptions);
     _setTrafficLayer(_googleMap!, newConfiguration.trafficEnabled ?? false);
@@ -300,6 +324,13 @@ class GoogleMapController {
         _configurationAndStyleToGmapsOptions(_lastMapConfiguration, styles));
   }
 
+  /// A getter for the current styles. Only for tests.
+  @visibleForTesting
+  List<gmaps.MapTypeStyle> get styles => _lastStyles;
+
+  /// Returns the last error from setting the map's style, if any.
+  String? get lastStyleError => _lastStyleError;
+
   // Sets new [gmaps.MapOptions] on the wrapped map.
   // ignore: use_setters_to_change_properties
   void _setOptions(gmaps.MapOptions options) {

packages/google_maps_flutter/google_maps_flutter_web/lib/src/google_maps_flutter_web.dart

@@ -279,6 +279,11 @@ class GoogleMapsPlugin extends GoogleMapsFlutterPlatform {
     return _events(mapId).whereType<MapLongPressEvent>();
   }
 
+  @override
+  Future<String?> getStyleError({required int mapId}) async {
+    return _map(mapId).lastStyleError;
+  }
+
   /// Disposes of the current map. It can't be used afterwards!
   @override
   void dispose({required int mapId}) {