fix(google-maps): avoid event listener leaks if inputs change

src/google-maps/google-map/google-map.ts

@@ -190,7 +190,7 @@ export class GoogleMap implements OnChanges, OnInit, OnDestroy {
 
   private _googleMapChanges!: Observable<google.maps.Map>;
 
-  private readonly _listeners: google.maps.MapsEventListener[] = [];
+  private _listeners: google.maps.MapsEventListener[] = [];
 
   private readonly _options = new BehaviorSubject<google.maps.MapOptions>(DEFAULT_OPTIONS);
   private readonly _center =
@@ -235,9 +235,7 @@ export class GoogleMap implements OnChanges, OnInit, OnDestroy {
   ngOnDestroy() {
     this._destroy.next();
     this._destroy.complete();
-    for (let listener of this._listeners) {
-      listener.remove();
-    }
+    this._clearListeners();
   }
 
   /**
@@ -438,6 +436,9 @@ export class GoogleMap implements OnChanges, OnInit, OnDestroy {
   }
 
   private _initializeEventHandlers() {
+    // Ensure that we don't leak if called multiple times.
+    this._clearListeners();
+
     const eventHandlers = new Map<string, EventEmitter<void>>([
       ['bounds_changed', this.boundsChanged],
       ['center_changed', this.centerChanged],
@@ -482,4 +483,13 @@ export class GoogleMap implements OnChanges, OnInit, OnDestroy {
           }));
     }
   }
+
+  /** Clears all currently-registered event listeners. */
+  private _clearListeners() {
+    for (let listener of this._listeners) {
+      listener.remove();
+    }
+
+    this._listeners = [];
+  }
 }

src/google-maps/map-info-window/map-info-window.ts

@@ -80,7 +80,7 @@ export class MapInfoWindow implements OnInit, OnDestroy {
   private readonly _position =
       new BehaviorSubject<google.maps.LatLngLiteral|google.maps.LatLng|undefined>(undefined);
 
-  private readonly _listeners: google.maps.MapsEventListener[] = [];
+  private _listeners: google.maps.MapsEventListener[] = [];
 
   private readonly _destroy = new Subject<void>();
 
@@ -167,6 +167,9 @@ export class MapInfoWindow implements OnInit, OnDestroy {
   }
 
   private _initializeEventHandlers() {
+    // Ensure that we don't leak if called multiple times.
+    this._clearListeners();
+
     const eventHandlers = new Map<string, EventEmitter<void>>([
       ['closeclick', this.closeclick],
       ['content_changed', this.contentChanged],
@@ -182,4 +185,13 @@ export class MapInfoWindow implements OnInit, OnDestroy {
       }
     });
   }
+
+  /** Clears all currently-registered event listeners. */
+  private _clearListeners() {
+    for (let listener of this._listeners) {
+      listener.remove();
+    }
+
+    this._listeners = [];
+  }
 }

src/google-maps/map-marker/map-marker.ts

@@ -205,7 +205,7 @@ export class MapMarker implements OnInit, OnDestroy {
 
   private readonly _destroy = new Subject<void>();
 
-  private readonly _listeners: google.maps.MapsEventListener[] = [];
+  private _listeners: google.maps.MapsEventListener[] = [];
 
   _marker?: google.maps.Marker;
 
@@ -230,9 +230,7 @@ export class MapMarker implements OnInit, OnDestroy {
   ngOnDestroy() {
     this._destroy.next();
     this._destroy.complete();
-    for (let listener of this._listeners) {
-      listener.remove();
-    }
+    this._clearListeners();
     if (this._marker) {
       this._marker.setMap(null);
     }
@@ -390,6 +388,9 @@ export class MapMarker implements OnInit, OnDestroy {
   }
 
   private _initializeEventHandlers() {
+    // Ensure that we don't leak if called multiple times.
+    this._clearListeners();
+
     const eventHandlers = new Map<string, EventEmitter<void>>([
       ['animation_changed', this.animationChanged],
       ['clickable_changed', this.clickableChanged],
@@ -433,4 +434,13 @@ export class MapMarker implements OnInit, OnDestroy {
           }
         });
   }
+
+  /** Clears all currently-registered event listeners. */
+  private _clearListeners() {
+    for (let listener of this._listeners) {
+      listener.remove();
+    }
+
+    this._listeners = [];
+  }
 }