feat(compiler-ssr): compile portal (#775)

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

@@ -0,0 +1,20 @@
+import { ComponentInternalInstance, ssrContextKey } from 'vue'
+import { SSRContext, createBuffer, PushFn } from '../renderToString'
+
+export function ssrRenderPortal(
+  contentRenderFn: (push: PushFn) => void,
+  target: string,
+  parentComponent: ComponentInternalInstance
+) {
+  const { getBuffer, push } = createBuffer()
+
+  contentRenderFn(push)
+
+  const context = parentComponent.appContext.provides[
+    ssrContextKey as any
+  ] as SSRContext
+  const portalBuffers =
+    context.__portalBuffers || (context.__portalBuffers = {})
+
+  portalBuffers[target] = getBuffer()
+}

packages/server-renderer/src/index.ts

@@ -13,6 +13,7 @@ export {
 } from './helpers/ssrRenderAttrs'
 export { ssrInterpolate } from './helpers/ssrInterpolate'
 export { ssrRenderList } from './helpers/ssrRenderList'
+export { ssrRenderPortal } from './helpers/ssrRenderPortal'
 
 // v-model helpers
 export {

packages/server-renderer/src/renderToString.ts

@@ -45,9 +45,12 @@ const {
 // - A resolved buffer (recursive arrays of strings that can be unrolled
 //   synchronously)
 // - An async buffer (a Promise that resolves to a resolved buffer)
-type SSRBuffer = SSRBufferItem[]
-type SSRBufferItem = string | ResolvedSSRBuffer | Promise<ResolvedSSRBuffer>
-type ResolvedSSRBuffer = (string | ResolvedSSRBuffer)[]
+export type SSRBuffer = SSRBufferItem[]
+export type SSRBufferItem =
+  | string
+  | ResolvedSSRBuffer
+  | Promise<ResolvedSSRBuffer>
+export type ResolvedSSRBuffer = (string | ResolvedSSRBuffer)[]
 
 export type PushFn = (item: SSRBufferItem) => void
 
@@ -62,7 +65,7 @@ export type SSRContext = {
   >
 }
 
-function createBuffer() {
+export function createBuffer() {
   let appendable = false
   let hasAsync = false
   const buffer: SSRBuffer = []