WIP

packages/google_maps_flutter/google_maps_flutter_platform_interface/lib/src/events/map_event.dart

@@ -51,7 +51,7 @@ class MapEvent<T> {
 /// A `MapEvent` associated to a `position`.
 class _PositionedMapEvent<T> extends MapEvent<T> {
   /// The position where this event happened.
-  final LatLng position;
+  final LatLng/*!*/ position;
 
   /// Build a Positioned MapEvent, that relates a mapId and a position with a value.
   ///
@@ -73,11 +73,11 @@ class CameraMoveStartedEvent extends MapEvent<void> {
 }
 
 /// An event fired while the Camera of a [mapId] moves.
-class CameraMoveEvent extends MapEvent<CameraPosition> {
+class CameraMoveEvent extends MapEvent<CameraPosition/*!*/> {
   /// Build a CameraMove Event triggered from the map represented by `mapId`.
   ///
   /// The `value` of this event is a [CameraPosition] object with the current position of the Camera.
-  CameraMoveEvent(int mapId, CameraPosition position) : super(mapId, position);
+  CameraMoveEvent(int mapId, CameraPosition/*!*/ position) : super(mapId, position);
 }
 
 /// An event fired when the Camera of a [mapId] becomes idle.
@@ -141,13 +141,13 @@ class MapTapEvent extends _PositionedMapEvent<void> {
   /// Build an MapTap Event triggered from the map represented by `mapId`.
   ///
   /// The `position` of this event is the LatLng where the Map was tapped.
-  MapTapEvent(int mapId, LatLng position) : super(mapId, position, null);
+  MapTapEvent(int mapId, LatLng/*!*/ position) : super(mapId, position, null);
 }
 
 /// An event fired when a Map is long pressed.
 class MapLongPressEvent extends _PositionedMapEvent<void> {
   /// Build an MapTap Event triggered from the map represented by `mapId`.
   ///
   /// The `position` of this event is the LatLng where the Map was long pressed.
-  MapLongPressEvent(int mapId, LatLng position) : super(mapId, position, null);
+  MapLongPressEvent(int mapId, LatLng/*!*/ position) : super(mapId, position, null);
 }

packages/google_maps_flutter/google_maps_flutter_platform_interface/lib/src/method_channel/method_channel_google_maps_flutter.dart

@@ -28,7 +28,7 @@ import '../types/utils/tile_overlay.dart';
 class MethodChannelGoogleMapsFlutter extends GoogleMapsFlutterPlatform {
   // Keep a collection of id -> channel
   // Every method call passes the int mapId
-  final Map<int, MethodChannel> _channels = {};
+  final Map<int, MethodChannel/*!*/> _channels = {};
 
   /// Accesses the MethodChannel associated to the passed mapId.
   MethodChannel channel(int mapId) {
@@ -43,8 +43,8 @@ class MethodChannelGoogleMapsFlutter extends GoogleMapsFlutterPlatform {
   /// This method is called when the plugin is first initialized.
   @override
   Future<void> init(int mapId) {
-    MethodChannel channel;
-    if (!_channels.containsKey(mapId)) {
+    MethodChannel channel = _channels[mapId];
+    if (channel == null) {
       channel = MethodChannel('plugins.flutter.io/google_maps_$mapId');
       channel.setMethodCallHandler(
           (MethodCall call) => _handleMethodCall(call, mapId));

packages/google_maps_flutter/google_maps_flutter_platform_interface/lib/src/types/bitmap.dart

@@ -4,6 +4,7 @@
 
 import 'dart:async' show Future;
 import 'dart:typed_data' show Uint8List;
+import 'dart:ui' show Size;
 
 import 'package:flutter/material.dart'
     show ImageConfiguration, AssetImage, AssetBundleImageKey;
@@ -110,14 +111,15 @@ class BitmapDescriptor {
         AssetImage(assetName, package: package, bundle: bundle);
     final AssetBundleImageKey assetBundleImageKey =
         await assetImage.obtainKey(configuration);
+    final Size size = configuration?.size;
     return BitmapDescriptor._(<dynamic>[
       _fromAssetImage,
       assetBundleImageKey.name,
       assetBundleImageKey.scale,
-      if (kIsWeb && configuration?.size != null)
+      if (kIsWeb && size != null)
         [
-          configuration.size.width,
-          configuration.size.height,
+          size.width,
+          size.height,
         ],
     ]);
   }

packages/google_maps_flutter/google_maps_flutter_platform_interface/lib/src/types/camera.dart

@@ -77,9 +77,13 @@ class CameraPosition {
     if (json == null) {
       return null;
     }
+    final LatLng target = LatLng.fromJson(json['target']);
+    if (target == null) {
+      return null;
+    }
     return CameraPosition(
       bearing: json['bearing'],
-      target: LatLng.fromJson(json['target']),
+      target: target,
       tilt: json['tilt'],
       zoom: json['zoom'],
     );

packages/google_maps_flutter/google_maps_flutter_platform_interface/lib/src/types/circle.dart

@@ -127,7 +127,7 @@ class Circle {
   dynamic toJson() {
     final Map<String, dynamic> json = <String, dynamic>{};
 
-    void addIfPresent(String fieldName, dynamic value) {
+    void addIfPresent(String fieldName, Object/*?*/ value) {
       if (value != null) {
         json[fieldName] = value;
       }

packages/google_maps_flutter/google_maps_flutter_platform_interface/lib/src/types/marker.dart

@@ -69,7 +69,7 @@ class InfoWindow {
   dynamic _toJson() {
     final Map<String, dynamic> json = <String, dynamic>{};
 
-    void addIfPresent(String fieldName, dynamic value) {
+    void addIfPresent(String fieldName, Object/*?*/ value) {
       if (value != null) {
         json[fieldName] = value;
       }
@@ -271,7 +271,7 @@ class Marker {
   Map<String, dynamic> toJson() {
     final Map<String, dynamic> json = <String, dynamic>{};
 
-    void addIfPresent(String fieldName, dynamic value) {
+    void addIfPresent(String fieldName, Object/*?*/ value) {
       if (value != null) {
         json[fieldName] = value;
       }

packages/google_maps_flutter/google_maps_flutter_platform_interface/lib/src/types/polygon.dart

@@ -147,7 +147,7 @@ class Polygon {
   dynamic toJson() {
     final Map<String, dynamic> json = <String, dynamic>{};
 
-    void addIfPresent(String fieldName, dynamic value) {
+    void addIfPresent(String fieldName, Object/*?*/ value) {
       if (value != null) {
         json[fieldName] = value;
       }

packages/google_maps_flutter/google_maps_flutter_platform_interface/lib/src/types/polyline.dart

@@ -177,7 +177,7 @@ class Polyline {
   dynamic toJson() {
     final Map<String, dynamic> json = <String, dynamic>{};
 
-    void addIfPresent(String fieldName, dynamic value) {
+    void addIfPresent(String fieldName, Object/*?*/ value) {
       if (value != null) {
         json[fieldName] = value;
       }

packages/google_maps_flutter/google_maps_flutter_platform_interface/lib/src/types/tile.dart

@@ -27,7 +27,7 @@ class Tile {
   Map<String, dynamic> toJson() {
     final Map<String, dynamic> json = <String, dynamic>{};
 
-    void addIfPresent(String fieldName, dynamic value) {
+    void addIfPresent(String fieldName, Object/*?*/ value) {
       if (value != null) {
         json[fieldName] = value;
       }

packages/google_maps_flutter/google_maps_flutter_platform_interface/lib/src/types/tile_overlay.dart

@@ -125,7 +125,7 @@ class TileOverlay {
   Map<String, dynamic> toJson() {
     final Map<String, dynamic> json = <String, dynamic>{};
 
-    void addIfPresent(String fieldName, dynamic value) {
+    void addIfPresent(String fieldName, Object/*?*/ value) {
       if (value != null) {
         json[fieldName] = value;
       }

packages/google_maps_flutter/google_maps_flutter_platform_interface/lib/src/types/tile_provider.dart

@@ -12,5 +12,5 @@ abstract class TileProvider {
   /// Returns the tile to be used for this tile coordinate.
   ///
   /// See [TileOverlay] for the specification of tile coordinates.
-  Future<Tile> getTile(int x, int y, int zoom);
+  Future<Tile> getTile(int/*!*/ x, int/*!*/ y, int zoom);
 }

packages/google_maps_flutter/google_maps_flutter_platform_interface/lib/src/types/utils/circle.dart

@@ -14,7 +14,7 @@ Map<CircleId, Circle> keyByCircleId(Iterable<Circle> circles) {
 }
 
 /// Converts a Set of Circles into something serializable in JSON.
-List<Map<String, dynamic>> serializeCircleSet(Set<Circle> circles) {
+List<Map<String, dynamic>> serializeCircleSet(Set<Circle/*!*/>/*!*/ circles) {
   if (circles == null) {
     return null;
   }

packages/google_maps_flutter/google_maps_flutter_platform_interface/lib/src/types/utils/marker.dart

@@ -14,7 +14,7 @@ Map<MarkerId, Marker> keyByMarkerId(Iterable<Marker> markers) {
 }
 
 /// Converts a Set of Markers into something serializable in JSON.
-List<Map<String, dynamic>> serializeMarkerSet(Set<Marker> markers) {
+List<Map<String, dynamic>> serializeMarkerSet(Set<Marker/*!*/>/*!*/ markers) {
   if (markers == null) {
     return null;
   }

packages/google_maps_flutter/google_maps_flutter_platform_interface/lib/src/types/utils/polygon.dart

@@ -14,7 +14,7 @@ Map<PolygonId, Polygon> keyByPolygonId(Iterable<Polygon> polygons) {
 }
 
 /// Converts a Set of Polygons into something serializable in JSON.
-List<Map<String, dynamic>> serializePolygonSet(Set<Polygon> polygons) {
+List<Map<String, dynamic>> serializePolygonSet(Set<Polygon/*!*/>/*!*/ polygons) {
   if (polygons == null) {
     return null;
   }

packages/google_maps_flutter/google_maps_flutter_platform_interface/lib/src/types/utils/polyline.dart

@@ -15,7 +15,7 @@ Map<PolylineId, Polyline> keyByPolylineId(Iterable<Polyline> polylines) {
 }
 
 /// Converts a Set of Polylines into something serializable in JSON.
-List<Map<String, dynamic>> serializePolylineSet(Set<Polyline> polylines) {
+List<Map<String, dynamic>> serializePolylineSet(Set<Polyline/*!*/>/*!*/ polylines) {
   if (polylines == null) {
     return null;
   }

packages/google_maps_flutter/google_maps_flutter_platform_interface/lib/src/types/utils/tile_overlay.dart

@@ -1,8 +1,8 @@
 import '../types.dart';
 
 /// Converts an [Iterable] of TileOverlay in a Map of TileOverlayId -> TileOverlay.
-Map<TileOverlayId, TileOverlay> keyTileOverlayId(
-    Iterable<TileOverlay> tileOverlays) {
+Map<TileOverlayId/*!*/, TileOverlay> keyTileOverlayId(
+    Iterable<TileOverlay>/*!*/ tileOverlays) {
   if (tileOverlays == null) {
     return <TileOverlayId, TileOverlay>{};
   }
@@ -13,7 +13,7 @@ Map<TileOverlayId, TileOverlay> keyTileOverlayId(
 
 /// Converts a Set of TileOverlays into something serializable in JSON.
 List<Map<String, dynamic>> serializeTileOverlaySet(
-    Set<TileOverlay> tileOverlays) {
+    Set<TileOverlay/*!*/>/*!*/ tileOverlays) {
   if (tileOverlays == null) {
     return null;
   }

packages/google_maps_flutter/google_maps_flutter_platform_interface/pubspec.yaml

@@ -9,14 +9,14 @@ dependencies:
   flutter:
     sdk: flutter
   meta: ^1.0.5
-  plugin_platform_interface: ^1.0.1
-  stream_transform: ^1.2.0
+  plugin_platform_interface: ^1.1.0-nullsafety.2
+  stream_transform: ^2.0.0-nullsafety.0
   collection: ^1.14.13
 
 dev_dependencies:
   flutter_test:
     sdk: flutter
-  mockito: ^4.1.1
+  mockito: ^5.0.0-nullsafety.0
   pedantic: ^1.8.0
 
 environment: