fix(server-renderer): render className during SSR (#11722)

Author: KazariEX

packages/server-renderer/__tests__/ssrRenderAttrs.spec.ts

@@ -143,6 +143,19 @@ describe('ssr: renderClass', () => {
   test('escape class values', () => {
     expect(ssrRenderClass(`"><script`)).toBe(`&quot;&gt;&lt;script`)
   })
+
+  test('className', () => {
+    expect(
+      ssrRenderAttrs({
+        className: 'foo',
+      }),
+    ).toBe(` class="foo"`)
+    expect(
+      ssrRenderAttrs({
+        className: ['foo', 'bar'],
+      }),
+    ).toBe(` class="foo,bar"`)
+  })
 })
 
 describe('ssr: renderStyle', () => {

packages/server-renderer/src/helpers/ssrRenderAttrs.ts

@@ -39,6 +39,8 @@ export function ssrRenderAttrs(
       ret += ` class="${ssrRenderClass(value)}"`
     } else if (key === 'style') {
       ret += ` style="${ssrRenderStyle(value)}"`
+    } else if (key === 'className') {
+      ret += ` class="${String(value)}"`
     } else {
       ret += ssrRenderDynamicAttr(key, value, tag)
     }