More pre-migration adjustment

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

@@ -15,6 +15,22 @@ import 'package:stream_transform/stream_transform.dart';
 import '../types/tile_overlay_updates.dart';
 import '../types/utils/tile_overlay.dart';
 
+/// Error thrown when an unknown map ID is provided to a method channel API.
+class UnknownMapIDError extends Error {
+  /// Message describing the assertion error.
+  final Object message;
+
+  /// Creates an assertion error with the provided [message].
+  UnknownMapIDError([this.message]);
+
+  String toString() {
+    if (message != null) {
+      return "Unknown map ID: ${Error.safeToString(message)}";
+    }
+    return "Unknown map ID";
+  }
+}
+
 /// An implementation of [GoogleMapsFlutterPlatform] that uses [MethodChannel] to communicate with the native code.
 ///
 /// The `google_maps_flutter` plugin code itself never talks to the native code directly. It delegates
@@ -32,7 +48,11 @@ class MethodChannelGoogleMapsFlutter extends GoogleMapsFlutterPlatform {
 
   /// Accesses the MethodChannel associated to the passed mapId.
   MethodChannel channel(int mapId) {
-    return _channels[mapId];
+    MethodChannel channel = _channels[mapId];
+    if (channel == null) {
+      throw UnknownMapIDError();
+    }
+    return channel;
   }
 
   // Keep a collection of mapId to a map of TileOverlays.
@@ -190,16 +210,17 @@ class MethodChannelGoogleMapsFlutter extends GoogleMapsFlutterPlatform {
         ));
         break;
       case 'tileOverlay#getTile':
-        final Map<TileOverlayId, TileOverlay> tileOverlaysForThisMap =
+        final Map<TileOverlayId, TileOverlay>/*?*/ tileOverlaysForThisMap =
             _tileOverlays[mapId];
         final String tileOverlayId = call.arguments['tileOverlayId'];
+        /* XXX fix this*/
         final TileOverlay tileOverlay =
-            tileOverlaysForThisMap[TileOverlayId(tileOverlayId)];
-        Tile tile;
-        if (tileOverlay == null || tileOverlay.tileProvider == null) {
+            tileOverlaysForThisMap/*?*/[TileOverlayId(tileOverlayId)];
+        TileProvider tileProvider = tileOverlay?.tileProvider;
+        if (tileProvider == null) {
           return TileProvider.noTile.toJson();
         }
-        tile = await tileOverlay.tileProvider.getTile(
+        final Tile tile = await tileProvider.getTile(
           call.arguments['x'],
           call.arguments['y'],
           call.arguments['zoom'],
@@ -312,7 +333,7 @@ class MethodChannelGoogleMapsFlutter extends GoogleMapsFlutterPlatform {
   /// If `newTileOverlays` is null, all the [TileOverlays] are removed for the Map with `mapId`.
   @override
   Future<void> updateTileOverlays({
-    Set<TileOverlay> newTileOverlays,
+    @required Set<TileOverlay> newTileOverlays,
     @required int mapId,
   }) {
     final Map<TileOverlayId, TileOverlay> currentTileOverlays =
@@ -491,7 +512,7 @@ class MethodChannelGoogleMapsFlutter extends GoogleMapsFlutterPlatform {
   ///   * [showMarkerInfoWindow] to show the Info Window.
   ///   * [hideMarkerInfoWindow] to hide the Info Window.
   @override
-  Future<bool> isMarkerInfoWindowShown(
+  Future<bool/*!*/> isMarkerInfoWindowShown(
     MarkerId markerId, {
     @required int mapId,
   }) {
@@ -502,7 +523,7 @@ class MethodChannelGoogleMapsFlutter extends GoogleMapsFlutterPlatform {
 
   /// Returns the current zoom level of the map
   @override
-  Future<double> getZoomLevel({
+  Future<double/*!*/> getZoomLevel({
     @required int mapId,
   }) {
     return channel(mapId).invokeMethod<double>('map#getZoomLevel');

packages/google_maps_flutter/google_maps_flutter_platform_interface/lib/src/platform_interface/google_maps_flutter_platform.dart

@@ -122,7 +122,7 @@ abstract class GoogleMapsFlutterPlatform extends PlatformInterface {
   ///
   /// The returned [Future] completes after listeners have been notified.
   Future<void> updateTileOverlays({
-    Set<TileOverlay> newTileOverlays,
+    @required Set<TileOverlay> newTileOverlays,
     @required int mapId,
   }) {
     throw UnimplementedError('updateTileOverlays() has not been implemented.');
@@ -252,15 +252,15 @@ abstract class GoogleMapsFlutterPlatform extends PlatformInterface {
   /// * See also:
   ///   * [showMarkerInfoWindow] to show the Info Window.
   ///   * [hideMarkerInfoWindow] to hide the Info Window.
-  Future<bool> isMarkerInfoWindowShown(
+  Future<bool/*!*/> isMarkerInfoWindowShown(
     MarkerId markerId, {
     @required int mapId,
   }) {
     throw UnimplementedError('updateMapOptions() has not been implemented.');
   }
 
   /// Returns the current zoom level of the map
-  Future<double> getZoomLevel({
+  Future<double/*!*/> getZoomLevel({
     @required int mapId,
   }) {
     throw UnimplementedError('getZoomLevel() has not been implemented.');

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

@@ -13,11 +13,11 @@ class CircleUpdates extends MapsObjectUpdates<Circle> {
   CircleUpdates.from(Set<Circle> previous, Set<Circle> current) : super.from(previous, current, objectName: 'circle');
 
   /// Set of Circles to be added in this update.
-  Set<Circle/*!*/> get circlesToAdd => objectsToAdd;
+  Set<Circle> get circlesToAdd => objectsToAdd;
 
   /// Set of CircleIds to be removed in this update.
-  Set<CircleId>/*?*/ get circleIdsToRemove => objectIdsToRemove.cast<CircleId>();
+  Set<CircleId> get circleIdsToRemove => objectIdsToRemove.cast<CircleId>();
 
   /// Set of Circles to be changed in this update.
-  Set<Circle/*!*/> get circlesToChange => objectsToChange;
+  Set<Circle> get circlesToChange => objectsToChange;
 }

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

@@ -40,7 +40,7 @@ class MapsObjectUpdates<T extends MapsObject> {
     ///
     /// It is a programming error to call this with an ID that is not guaranteed
     /// to be in [currentObjects].
-    T _idToCurrentObject(MapsObjectId<T> id) {
+    T/*!*/ _idToCurrentObject(MapsObjectId<T> id) {
       return currentObjects[id];
     }
 
@@ -73,21 +73,21 @@ class MapsObjectUpdates<T extends MapsObject> {
     return _objectsToAdd;
   }
 
-  Set<T> _objectsToAdd;
+  /*late*/ Set<T> _objectsToAdd;
 
   /// Set of objects to be removed in this update.
   Set<MapsObjectId<T>> get objectIdsToRemove {
     return _objectIdsToRemove;
   }
 
-  Set<MapsObjectId<T>> _objectIdsToRemove;
+  /*late*/ Set<MapsObjectId<T>> _objectIdsToRemove;
 
   /// Set of objects to be changed in this update.
   Set<T> get objectsToChange {
     return _objectsToChange;
   }
 
-  Set<T> _objectsToChange;
+  /*late*/ Set<T> _objectsToChange;
 
   /// Converts this object to JSON.
   Map<String, dynamic> toJson() {

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

@@ -20,14 +20,14 @@ class ScreenCoordinate {
   });
 
   /// Represents the number of pixels from the left of the [GoogleMap].
-  final int x;
+  final int/*!*/ x;
 
   /// Represents the number of pixels from the top of the [GoogleMap].
-  final int y;
+  final int/*!*/ y;
 
   /// Converts this object to something serializable in JSON.
   dynamic toJson() {
-    return <String, int>{
+    return <String, int/*!*/>{
       "x": x,
       "y": y,
     };

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

@@ -12,10 +12,10 @@ class Tile {
   const Tile(this.width, this.height, this.data);
 
   /// The width of the image encoded by data in logical pixels.
-  final int width;
+  final int/*!*/ width;
 
   /// The height of the image encoded by data in logical pixels.
-  final int height;
+  final int/*!*/ height;
 
   /// A byte array containing the image data.
   ///

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

@@ -11,6 +11,6 @@ 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) {
   return serializeMapsObjectSet(circles);
 }

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

@@ -11,6 +11,6 @@ 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) {
   return serializeMapsObjectSet(markers);
 }

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

@@ -11,6 +11,6 @@ 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) {
   return serializeMapsObjectSet(polygons);
 }

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

@@ -6,13 +6,13 @@ import '../types.dart';
 import 'maps_object.dart';
 
 /// Converts an [Iterable] of TileOverlay in a Map of TileOverlayId -> TileOverlay.
-Map<TileOverlayId/*!*/, TileOverlay> keyTileOverlayId(
+Map<TileOverlayId, TileOverlay> keyTileOverlayId(
     Iterable<TileOverlay>/*?*/ tileOverlays) {
   return keyByMapsObjectId<TileOverlay>(tileOverlays).cast<TileOverlayId, TileOverlay>();
 }
 
 /// Converts a Set of TileOverlays into something serializable in JSON.
 List<Map<String, dynamic>> serializeTileOverlaySet(
-    Set<TileOverlay/*!*/> tileOverlays) {
+    Set<TileOverlay> tileOverlays) {
   return serializeMapsObjectSet(tileOverlays);
 }