test: configure namespace and zindex for loading (#12485)

packages/components/config-provider/__tests__/config-loading.test.tsx

@@ -0,0 +1,27 @@
+import { mount } from '@vue/test-utils'
+import { describe, expect, it } from 'vitest'
+import { ElButton, ElLoading } from '@element-plus/components'
+import ConfigProvider from '../src/config-provider'
+import type { LoadingInstance } from '@element-plus/components/loading/src/loading'
+
+describe('loading config', () => {
+  it('should render loading component', async () => {
+    let instance: LoadingInstance
+    const startLoading = () => {
+      instance = ElLoading.service()
+    }
+    const wrapper = mount(() => (
+      <ConfigProvider namespace="ep" zIndex={10000}>
+        <ElButton onClick={startLoading}>test</ElButton>
+      </ConfigProvider>
+    ))
+    const btn = wrapper.find('.ep-button')
+    btn.trigger('click')
+    expect(btn).not.toBeNull()
+    const mask = document.querySelector<HTMLElement>('.ep-loading-mask')
+    expect(mask).not.toBeNull()
+    expect(mask?.style.zIndex).toBe('10001')
+    // @ts-expect-error
+    instance.close()
+  })
+})