test: add unit tests for base components (#32818)

Co-authored-by: CodingOnStar <hanxujiang@dify.com>

web/app/components/base/loading/__tests__/index.spec.tsx

@@ -0,0 +1,28 @@
+import { render } from '@testing-library/react'
+import * as React from 'react'
+import Loading from '../index'
+
+describe('Loading Component', () => {
+  it('renders correctly with default props', () => {
+    const { container } = render(<Loading />)
+    expect(container.firstChild).toHaveClass('flex w-full items-center justify-center')
+    expect(container.firstChild).not.toHaveClass('h-full')
+  })
+
+  it('renders correctly with area type', () => {
+    const { container } = render(<Loading type="area" />)
+    expect(container.firstChild).not.toHaveClass('h-full')
+  })
+
+  it('renders correctly with app type', () => {
+    const { container } = render(<Loading type="app" />)
+    expect(container.firstChild).toHaveClass('h-full')
+  })
+
+  it('contains SVG with spin-animation class', () => {
+    const { container } = render(<Loading />)
+
+    const svgElement = container.querySelector('svg')
+    expect(svgElement).toHaveClass('spin-animation')
+  })
+})