wip(srr): slot outlet

packages/compiler-ssr/src/transforms/ssrTransformSlotOutlet.ts

@@ -1,3 +1,49 @@
-import { NodeTransform } from '@vue/compiler-dom'
+import {
+  NodeTransform,
+  isSlotOutlet,
+  processSlotOutlet,
+  createCallExpression,
+  SlotOutletNode,
+  createFunctionExpression,
+  createBlockStatement
+} from '@vue/compiler-dom'
+import { SSR_RENDER_SLOT } from '../runtimeHelpers'
+import {
+  SSRTransformContext,
+  createChildContext,
+  processChildren
+} from '../ssrCodegenTransform'
 
-export const ssrTransformSlotOutlet: NodeTransform = () => {}
+export const ssrTransformSlotOutlet: NodeTransform = (node, context) => {
+  if (isSlotOutlet(node)) {
+    const { slotName, slotProps } = processSlotOutlet(node, context)
+    node.ssrCodegenNode = createCallExpression(
+      context.helper(SSR_RENDER_SLOT),
+      [
+        `_ctx.$slots`,
+        slotName,
+        slotProps || `{}`,
+        `null`, // fallback content placeholder.
+        `_push`,
+        `_parent`
+      ]
+    )
+  }
+}
+
+export function ssrProcessSlotOutlet(
+  node: SlotOutletNode,
+  context: SSRTransformContext
+) {
+  const renderCall = node.ssrCodegenNode!
+  // has fallback content
+  if (node.children.length) {
+    const childContext = createChildContext(context)
+    processChildren(node.children, childContext)
+    const fallbackRenderFn = createFunctionExpression([])
+    fallbackRenderFn.body = createBlockStatement(childContext.body)
+    // _renderSlot(slots, name, props, fallback, ...)
+    renderCall.arguments[3] = fallbackRenderFn
+  }
+  context.pushStatement(node.ssrCodegenNode!)
+}