native gesture bugfix

Author: akwasniewski

packages/react-native-gesture-handler/src/web/handlers/NativeViewGestureHandler.ts

@@ -46,9 +46,11 @@ export default class NativeViewGestureHandler extends GestureHandler {
     if (this.config.disallowInterruption !== undefined) {
       this.disallowInterruption = this.config.disallowInterruption;
     }
-
-    const view = this.delegate.view as HTMLElement;
-    this.restoreViewStyles(view);
+    if (this.delegate.isInitialized) {
+      // this function is called on handler creation, which happens before initializing delegate
+      const view = this.delegate.view as HTMLElement;
+      this.restoreViewStyles(view);
+    }
   }
 
   private restoreViewStyles(view: HTMLElement) {

packages/react-native-gesture-handler/src/web/tools/GestureHandlerDelegate.ts

@@ -8,6 +8,7 @@ export interface MeasureResult {
 }
 
 export interface GestureHandlerDelegate<TComponent, THandler> {
+  isInitialized: boolean;
   view: TComponent;
 
   init(viewRef: number, handler: THandler): void;

packages/react-native-gesture-handler/src/web/tools/GestureHandlerWebDelegate.ts

@@ -12,6 +12,7 @@ import { Config } from '../interfaces';
 import { MouseButton } from '../../handlers/gestureHandlerCommon';
 import KeyboardEventManager from './KeyboardEventManager';
 import WheelEventManager from './WheelEventManager';
+import { tagMessage } from '../../utils';
 
 interface DefaultViewStyles {
   userSelect: string;
@@ -21,7 +22,7 @@ interface DefaultViewStyles {
 export class GestureHandlerWebDelegate
   implements GestureHandlerDelegate<HTMLElement, IGestureHandler>
 {
-  private isInitialized = false;
+  public isInitialized = false;
   private _view: HTMLElement | null = null;
 
   private gestureHandler!: IGestureHandler;
@@ -233,7 +234,11 @@ export class GestureHandlerWebDelegate
   }
 
   public get view() {
-    return this._view!;
+    if (!this._view) {
+      throw new Error(tagMessage("component's view is null"));
+    }
+
+    return this._view;
   }
   public set view(value: HTMLElement) {
     this._view = value;