feat: add next helper for sibilings

packages/compiler-vapor/__tests__/transforms/__snapshots__/transformChildren.spec.ts.snap

@@ -0,0 +1,19 @@
+// Vitest Snapshot v1, https://vitest.dev/guide/snapshot.html
+
+exports[`compiler: children transform > children & sibling references 1`] = `
+"import { next as _next, setText as _setText, createTextNode as _createTextNode, insert as _insert, template as _template } from 'vue/vapor';
+const t0 = _template("<div><p></p> <!><p></p></div>")
+
+export function render(_ctx) {
+  const n4 = t0()
+  const n0 = n4.firstChild
+  const n3 = _next(n0, 2)
+  const n2 = n3.nextSibling
+  _setText(n0, 'first')
+  const n1 = _createTextNode()
+  _setText(n1, 'second', " ", 'third', " ")
+  _setText(n2, 'forth')
+  _insert(n1, n4, n3)
+  return n4
+}"
+`;

packages/compiler-vapor/__tests__/transforms/__snapshots__/vOnce.spec.ts.snap

@@ -12,12 +12,12 @@ export function render(_ctx) {
 `;
 
 exports[`compiler: v-once > basic 1`] = `
-"import { children as _children, createTextNode as _createTextNode, setText as _setText, setClass as _setClass, prepend as _prepend, template as _template } from 'vue/vapor';
+"import { createTextNode as _createTextNode, setText as _setText, setClass as _setClass, prepend as _prepend, template as _template } from 'vue/vapor';
 const t0 = _template("<div><span></span></div>")
 
 export function render(_ctx) {
   const n2 = t0()
-  const n1 = _children(n2, 0)
+  const n1 = n2.firstChild
   const n0 = _createTextNode()
   _setText(n0, _ctx.msg, " ")
   _setClass(n1, _ctx.clz)
@@ -37,12 +37,12 @@ export function render(_ctx) {
 `;
 
 exports[`compiler: v-once > on nested plain element 1`] = `
-"import { children as _children, setDynamicProp as _setDynamicProp, template as _template } from 'vue/vapor';
+"import { setDynamicProp as _setDynamicProp, template as _template } from 'vue/vapor';
 const t0 = _template("<div><div></div></div>")
 
 export function render(_ctx) {
   const n1 = t0()
-  const n0 = _children(n1, 0)
+  const n0 = n1.firstChild
   _setDynamicProp(n0, "id", _ctx.foo)
   return n1
 }"

packages/compiler-vapor/__tests__/transforms/transformChildren.spec.ts

@@ -1,3 +1,39 @@
+import { makeCompile } from './_utils'
+import {
+  transformChildren,
+  transformElement,
+  transformText,
+  transformVIf,
+} from '../../src'
+
+const compileWithElementTransform = makeCompile({
+  nodeTransforms: [
+    transformText,
+    transformVIf,
+    transformElement,
+    transformChildren,
+  ],
+})
+
 describe('compiler: children transform', () => {
   test.todo('basic')
+
+  test('children & sibling references', () => {
+    const { code, vaporHelpers } = compileWithElementTransform(
+      `<div>
+        <p>{{'first'}}</p>
+        {{'second'}}
+        {{'third'}}
+        <p>{{'forth'}}</p>
+      </div>`,
+    )
+    expect(code).toMatchSnapshot()
+    expect(Array.from(vaporHelpers)).containSubset([
+      'next',
+      'setText',
+      'createTextNode',
+      'insert',
+      'template',
+    ])
+  })
 })

packages/compiler-vapor/src/generators/template.ts

@@ -1,6 +1,6 @@
 import type { CodegenContext } from '../generate'
 import { DynamicFlag, type IRDynamicInfo } from '../ir'
-import { NEWLINE, buildCodeFragment, genCall } from './utils'
+import { type CodeFragment, NEWLINE, buildCodeFragment, genCall } from './utils'
 
 export function genTemplates(
   templates: string[],
@@ -19,7 +19,7 @@ export function genChildren(
   context: CodegenContext,
   from: number,
   paths: number[] = [],
-) {
+): CodeFragment[] {
   const { vaporHelper } = context
   const [frag, push] = buildCodeFragment()
   let offset = 0
@@ -29,6 +29,7 @@ export function genChildren(
     push(NEWLINE, `const n${id} = t${template}()`)
   }
 
+  let prev: [id: number, elementIndex: number] | undefined
   for (const [index, child] of children.entries()) {
     if (child.flags & DynamicFlag.NON_TEMPLATE) {
       offset--
@@ -44,21 +45,35 @@ export function genChildren(
     const elementIndex = Number(index) + offset
     const newPaths = [...paths, elementIndex]
 
-    if (id !== undefined) {
+    if (id === undefined) {
+      push(...genChildren(child, context, from, newPaths))
+      continue
+    }
+
+    push(NEWLINE, `const n${id} = `)
+    if (prev) {
+      const offset = elementIndex - prev[1]
+      if (offset === 1) {
+        push(`n${prev[0]}.nextSibling`)
+      } else {
+        push(...genCall(vaporHelper('next'), `n${prev[0]}`, String(offset)))
+      }
+    } else {
+      if (newPaths.length === 1 && newPaths[0] === 0) {
+        push(`n${from}.firstChild`)
+      } else {
         push(
-        NEWLINE,
-        `const n${id} = `,
           ...genCall(
             vaporHelper('children'),
             `n${from}`,
             ...newPaths.map(String),
           ),
         )
-      push(...genChildren(child, context, id, []))
-    } else {
-      push(...genChildren(child, context, from, newPaths))
       }
     }
+    prev = [id, elementIndex]
+    push(...genChildren(child, context, id, []))
+  }
 
   return frag
 }

packages/compiler-vapor/src/transforms/transformChildren.ts

@@ -21,7 +21,6 @@ export const transformChildren: NodeTransform = (node, context) => {
 
   if (!isFragment && node.type !== NodeTypes.ELEMENT) return
 
-  let referencedCount = 0
   for (const [i, child] of node.children.entries()) {
     const childContext = createContext(
       child,
@@ -42,18 +41,12 @@ export const transformChildren: NodeTransform = (node, context) => {
       }
     } else {
       context.childrenTemplate.push(childContext.template)
-      if (childContext.dynamic.flags & DynamicFlag.REFERENCED) {
-        referencedCount++
-      }
     }
 
     context.dynamic.children[i] = childContext.dynamic
   }
 
   if (!isFragment) {
-    if (referencedCount > 1) {
-      context.reference()
-    }
     processDynamicChildren(context as TransformContext<ElementNode>)
   }
 }

packages/runtime-vapor/src/dom/template.ts

@@ -1,5 +1,3 @@
-import { isArray } from '@vue/shared'
-
 /*! #__NO_SIDE_EFFECTS__ */
 export function template(html: string) {
   let node: ChildNode
@@ -13,15 +11,19 @@ export function template(html: string) {
 }
 
 /*! #__NO_SIDE_EFFECTS__ */
-export function children(node: Node | Node[], ...paths: number[]): Node {
+export function children(node: Node, ...paths: number[]): Node {
   for (const idx of paths) {
-    if (isArray(node)) {
-      node = node[idx]
-    } else {
     for (let i = 0; i <= idx; i++) {
       node = (node as Node)[i === 0 ? 'firstChild' : 'nextSibling']!
     }
   }
+  return node as Node
+}
+
+/*! #__NO_SIDE_EFFECTS__ */
+export function next(node: Node, offset: number): Node {
+  for (let i = 0; i < offset; i++) {
+    node = (node as Node).nextSibling!
   }
   return node as Node
 }

packages/runtime-vapor/src/index.ts

@@ -73,7 +73,7 @@ export {
   type DirectiveModifiers,
 } from './directives'
 
-export { template, children } from './dom/template'
+export { template, children, next } from './dom/template'
 export { insert, prepend, remove, createTextNode } from './dom/element'
 export { setStyle } from './dom/style'
 export {