feat(ssr): compiler-ssr support for Suspense

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

@@ -0,0 +1,19 @@
+import { PushFn, ResolvedSSRBuffer, createBuffer } from '../renderToString'
+import { NOOP } from '@vue/shared'
+
+type ContentRenderFn = (push: PushFn) => void
+
+export async function ssrRenderSuspense({
+  default: renderContent = NOOP,
+  fallback: renderFallback = NOOP
+}: Record<string, ContentRenderFn | undefined>): Promise<ResolvedSSRBuffer> {
+  try {
+    const { push, getBuffer } = createBuffer()
+    renderContent(push)
+    return await getBuffer()
+  } catch {
+    const { push, getBuffer } = createBuffer()
+    renderFallback(push)
+    return getBuffer()
+  }
+}