[change] Fix the Dimensions.window value

Fixes issues in Safari from using window.innerWidth. Using
documentElement.clientWidth doesn't have issues and provides a more practical
value for the canvas width that excludes the width of scrollbars.

Fix #1369
Fix #1905

scripts/jest/setupFiles.js

@@ -6,5 +6,16 @@ class ResizeObserver {
   observe() {}
   unobserve() {}
 }
-
 window.ResizeObserver = ResizeObserver;
+
+// JSDOM doesn't provide values for 'clientWidth' etc
+Object.defineProperty(window.document.documentElement, 'clientHeight', {
+  get: function () {
+    return this._jsdomClientWidth || window.innerHeight;
+  }
+});
+Object.defineProperty(window.document.documentElement, 'clientWidth', {
+  get: function () {
+    return this._jsdomClientWidth || window.innerWidth;
+  }
+});