chore: refactor for consistency

packages/nuxt/src/app/components/nuxt-link.ts

@@ -14,7 +14,7 @@ import { onNuxtReady } from '../composables/ready'
 import { navigateTo, useRouter } from '../composables/router'
 import { useNuxtApp, useRuntimeConfig } from '../nuxt'
 import { cancelIdleCallback, requestIdleCallback } from '../compat/idle-callback'
-import type { CallbackFn, ObserveFn } from '../utils'
+import { useIntersectionObserver } from '../utils'
 
 // @ts-expect-error virtual file
 import { nuxtLinkDefaults } from '#build/nuxt.config.mjs'
@@ -306,7 +306,7 @@ export function defineNuxtLink (options: NuxtLinkOptions) {
           let idleId: number
           let unobserve: (() => void) | null = null
           onMounted(() => {
-            const observer = useObserver()
+            const observer = useIntersectionObserver()
             onNuxtReady(() => {
               idleId = requestIdleCallback(() => {
                 if (el?.value?.tagName) {
@@ -445,47 +445,6 @@ function applyTrailingSlashBehavior (to: string, trailingSlash: NuxtLinkOptions[
 
 // --- Prefetching utils ---
 
-function useObserver (): { observe: ObserveFn } | undefined {
-  if (import.meta.server) { return }
-
-  const nuxtApp = useNuxtApp()
-  if (nuxtApp._observer) {
-    return nuxtApp._observer
-  }
-
-  let observer: IntersectionObserver | null = null
-
-  const callbacks = new Map<Element, CallbackFn>()
-
-  const observe: ObserveFn = (element, callback) => {
-    if (!observer) {
-      observer = new IntersectionObserver((entries) => {
-        for (const entry of entries) {
-          const callback = callbacks.get(entry.target)
-          const isVisible = entry.isIntersecting || entry.intersectionRatio > 0
-          if (isVisible && callback) { callback() }
-        }
-      })
-    }
-    callbacks.set(element, callback)
-    observer.observe(element)
-    return () => {
-      callbacks.delete(element)
-      observer!.unobserve(element)
-      if (callbacks.size === 0) {
-        observer!.disconnect()
-        observer = null
-      }
-    }
-  }
-
-  const _observer = nuxtApp._observer = {
-    observe,
-  }
-
-  return _observer
-}
-
 function isSlowConnection () {
   if (import.meta.server) { return }
 

packages/nuxt/src/app/utils.ts

@@ -1,6 +1,50 @@
+import { useNuxtApp } from './nuxt'
+
+
 export function toArray<T> (value: T | T[]): T[] {
   return Array.isArray(value) ? value : [value]
 }
 
 export type CallbackFn = () => void
 export type ObserveFn = (element: Element, callback: CallbackFn) => () => void
+
+export function useIntersectionObserver (options?: IntersectionObserverInit): { observe: ObserveFn } {
+  if (import.meta.server) { return {observe: () => () => {}} }
+
+  const nuxtApp = useNuxtApp()
+  if (nuxtApp._observer) {
+    return nuxtApp._observer
+  }
+
+  let observer: IntersectionObserver | null = null
+
+  const callbacks = new Map<Element, CallbackFn>()
+
+  const observe: ObserveFn = (element, callback) => {
+    if (!observer) {
+      observer = new IntersectionObserver((entries) => {
+        for (const entry of entries) {
+          const callback = callbacks.get(entry.target)
+          const isVisible = entry.isIntersecting || entry.intersectionRatio > 0
+          if (isVisible && callback) { callback() }
+        }
+      },options)
+    }
+    callbacks.set(element, callback)
+    observer.observe(element)
+    return () => {
+      callbacks.delete(element)
+      observer!.unobserve(element)
+      if (callbacks.size === 0) {
+        observer!.disconnect()
+        observer = null
+      }
+    }
+  }
+
+  const _observer = nuxtApp._observer = {
+    observe,
+  }
+
+  return _observer
+}

packages/nuxt/src/components/runtime/client-delayed-component.ts

@@ -6,35 +6,7 @@ import { getFragmentHTML } from '#app/components/utils'
 import { useNuxtApp } from '#app/nuxt'
 import { cancelIdleCallback, requestIdleCallback } from '#app/compat/idle-callback'
 import { onNuxtReady } from '#app'
-
+import { useIntersectionObserver } from '#app/utils'
-function useIntersectionObserver (options: IntersectionObserverInit): { observe: ObserveFn } {
-  if (import.meta.server) { return { observe: () => () => {} } }
-
-  let observer: IntersectionObserver | null = null
-
-  const observe: ObserveFn = (element, callback) => {
-    if (!observer) {
-      observer = new IntersectionObserver((entries) => {
-        for (const entry of entries) {
-          const isVisible = entry.isIntersecting || entry.intersectionRatio > 0
-          if (isVisible && callback) { callback() }
-        }
-      }, options)
-    }
-    observer.observe(element)
-    return () => {
-      observer!.unobserve(element)
-      observer!.disconnect()
-      observer = null
-    }
-  }
-
-  const _observer = {
-    observe,
-  }
-
-  return _observer
-}
 
 function elementIsVisibleInViewport (el: Element) {
   const { top, left, bottom, right } = el.getBoundingClientRect()