Guard animateTarget window access in non-browser runtimes (#3735)

packages/motion-dom/src/animation/interfaces/__tests__/visual-element-target.test.ts

@@ -0,0 +1,38 @@
+/**
+ * @jest-environment node
+ */
+import { animateTarget } from "../visual-element-target"
+
+describe("animateTarget in a non-browser environment", () => {
+    const createValue = () => ({
+        get: () => 0,
+        set: () => {},
+        isAnimating: () => false,
+        start: () => {},
+        stop: () => {},
+        animation: undefined,
+    })
+
+    const createVisualElement = () => {
+        const values: Record<string, any> = {}
+        return {
+            getDefaultTransition: () => undefined,
+            animationState: undefined,
+            latestValues: {},
+            shouldReduceMotion: false,
+            props: {},
+            getValue: (key: string) => {
+                if (key === "willChange") return undefined
+                return (values[key] ||= createValue())
+            },
+            addValue: () => {},
+        } as any
+    }
+
+    it("does not throw when window is undefined", () => {
+        expect(typeof window).toBe("undefined")
+        expect(() =>
+            animateTarget(createVisualElement(), { opacity: 1 })
+        ).not.toThrow()
+    })
+})

packages/motion-dom/src/animation/interfaces/visual-element-target.ts

@@ -13,6 +13,8 @@ import type { TargetAndTransition } from "../../node/types"
 import type { AnimationTypeState } from "../../render/utils/animation-state"
 import type { VisualElement } from "../../render/VisualElement"
 
+const isBrowser = typeof window !== "undefined"
+
 /**
  * Decide whether we should block this animation. Previously, we achieved this
  * just by checking whether the key was listed in protectedKeys, but this
@@ -114,7 +116,7 @@ export function animateTarget(
          * to see if we're handling off from an existing animation.
          */
         let isHandoff = false
-        if (window.MotionHandoffAnimation) {
+        if (isBrowser && window.MotionHandoffAnimation) {
             const appearId = getOptimisedAppearId(visualElement)
 
             if (appearId) {