test: add unit tests for useInView hook

Author: rick-hup

tests/useInView.spec.ts

@@ -0,0 +1,49 @@
+import { beforeEach, describe, expect, it, vi } from 'vitest'
+import { mount } from '@vue/test-utils'
+import { defineComponent, h, nextTick, ref } from 'vue'
+import { useInView } from '../packages/motion/src/utils/use-in-view'
+
+// Mock IntersectionObserver
+const mockIntersectionObserver = vi.fn()
+mockIntersectionObserver.mockReturnValue({
+  observe: () => null,
+  unobserve: () => null,
+  disconnect: () => null,
+})
+window.IntersectionObserver = mockIntersectionObserver
+
+// Mock inView from framer-motion
+vi.mock('framer-motion/dom', () => ({
+  inView: (element: Element, onStart: Function, options = {}) => {
+    // Simulate the callback being called
+    const cleanup = onStart()
+    return () => {
+      if (cleanup)
+        cleanup()
+    }
+  },
+}))
+
+describe('useInView', () => {
+  beforeEach(() => {
+    vi.clearAllMocks()
+  })
+
+  it('should return a ref with initial value of false and update to true when element enters viewport', async () => {
+    const TestComponent = defineComponent({
+      setup() {
+        const elementRef = ref<HTMLDivElement | null>(null)
+        const isInView = useInView(elementRef)
+        return { isInView, elementRef }
+      },
+      render() {
+        return h('div', { ref: 'elementRef' })
+      },
+    })
+
+    const wrapper = mount(TestComponent)
+    expect(wrapper.vm.isInView).toBe(false)
+    await nextTick()
+    expect(wrapper.vm.isInView).toBe(true)
+  })
+})