feat: onServerPrefetch (#3070)

Support equivalent of `serverPrefetch` option via Composition API.

packages/runtime-core/src/apiLifecycle.ts

@@ -65,8 +65,9 @@ export function injectHook(
 export const createHook = <T extends Function = () => any>(
   lifecycle: LifecycleHooks
 ) => (hook: T, target: ComponentInternalInstance | null = currentInstance) =>
-  // post-create lifecycle registrations are noops during SSR
-  !isInSSRComponentSetup && injectHook(lifecycle, hook, target)
+  // post-create lifecycle registrations are noops during SSR (except for serverPrefetch)
+  (!isInSSRComponentSetup || lifecycle === LifecycleHooks.SERVER_PREFETCH) &&
+  injectHook(lifecycle, hook, target)
 
 export const onBeforeMount = createHook(LifecycleHooks.BEFORE_MOUNT)
 export const onMounted = createHook(LifecycleHooks.MOUNTED)
@@ -74,6 +75,7 @@ export const onBeforeUpdate = createHook(LifecycleHooks.BEFORE_UPDATE)
 export const onUpdated = createHook(LifecycleHooks.UPDATED)
 export const onBeforeUnmount = createHook(LifecycleHooks.BEFORE_UNMOUNT)
 export const onUnmounted = createHook(LifecycleHooks.UNMOUNTED)
+export const onServerPrefetch = createHook(LifecycleHooks.SERVER_PREFETCH)
 
 export type DebuggerHook = (e: DebuggerEvent) => void
 export const onRenderTriggered = createHook<DebuggerHook>(
@@ -83,15 +85,15 @@ export const onRenderTracked = createHook<DebuggerHook>(
   LifecycleHooks.RENDER_TRACKED
 )
 
-export type ErrorCapturedHook = (
-  err: unknown,
+export type ErrorCapturedHook<TError = unknown> = (
+  err: TError,
   instance: ComponentPublicInstance | null,
   info: string
 ) => boolean | void
 
-export const onErrorCaptured = (
-  hook: ErrorCapturedHook,
+export function onErrorCaptured<TError = Error>(
+  hook: ErrorCapturedHook<TError>,
   target: ComponentInternalInstance | null = currentInstance
-) => {
+) {
   injectHook(LifecycleHooks.ERROR_CAPTURED, hook, target)
 }

packages/runtime-core/src/component.ts

@@ -153,7 +153,7 @@ export type Component<
 
 export { ComponentOptions }
 
-type LifecycleHook = Function[] | null
+type LifecycleHook<TFn = Function> = TFn[] | null
 
 export const enum LifecycleHooks {
   BEFORE_CREATE = 'bc',
@@ -168,7 +168,8 @@ export const enum LifecycleHooks {
   ACTIVATED = 'a',
   RENDER_TRIGGERED = 'rtg',
   RENDER_TRACKED = 'rtc',
-  ERROR_CAPTURED = 'ec'
+  ERROR_CAPTURED = 'ec',
+  SERVER_PREFETCH = 'sp'
 }
 
 export interface SetupContext<E = EmitsOptions> {
@@ -414,6 +415,10 @@ export interface ComponentInternalInstance {
    * @internal
    */
   [LifecycleHooks.ERROR_CAPTURED]: LifecycleHook
+  /**
+   * @internal
+   */
+  [LifecycleHooks.SERVER_PREFETCH]: LifecycleHook<() => Promise<unknown>>
 }
 
 const emptyAppContext = createAppContext()
@@ -497,7 +502,8 @@ export function createComponentInstance(
     a: null,
     rtg: null,
     rtc: null,
-    ec: null
+    ec: null,
+    sp: null
   }
   if (__DEV__) {
     instance.ctx = createRenderContext(instance)

packages/runtime-core/src/componentOptions.ts

@@ -40,7 +40,8 @@ import {
   onDeactivated,
   onRenderTriggered,
   DebuggerHook,
-  ErrorCapturedHook
+  ErrorCapturedHook,
+  onServerPrefetch
 } from './apiLifecycle'
 import {
   reactive,
@@ -555,6 +556,7 @@ export function applyOptions(
     renderTracked,
     renderTriggered,
     errorCaptured,
+    serverPrefetch,
     // public API
     expose
   } = options
@@ -798,6 +800,9 @@ export function applyOptions(
   if (unmounted) {
     onUnmounted(unmounted.bind(publicThis))
   }
+  if (serverPrefetch) {
+    onServerPrefetch(serverPrefetch.bind(publicThis))
+  }
 
   if (__COMPAT__) {
     if (

packages/runtime-core/src/index.ts

@@ -37,7 +37,8 @@ export {
   onDeactivated,
   onRenderTracked,
   onRenderTriggered,
-  onErrorCaptured
+  onErrorCaptured,
+  onServerPrefetch
 } from './apiLifecycle'
 export { provide, inject } from './apiInject'
 export { nextTick } from './scheduler'