perf: use new Empty() instead of Object.create(null) for performance

Author: c0dedance

packages/compiler-core/src/babelUtils.ts

@@ -11,6 +11,7 @@ import type {
   ObjectProperty,
   Program,
 } from '@babel/types'
+import { Empty } from '@vue/shared'
 import { walk } from 'estree-walker'
 
 /**
@@ -27,7 +28,7 @@ export function walkIdentifiers(
   ) => void,
   includeAll = false,
   parentStack: Node[] = [],
-  knownIds: Record<string, number> = Object.create(null),
+  knownIds: Record<string, number> = new Empty(),
 ): void {
   if (__BROWSER__) {
     return

packages/compiler-core/src/transform.ts

@@ -22,6 +22,7 @@ import {
 } from './ast'
 import {
   EMPTY_OBJ,
+  Empty,
   NOOP,
   PatchFlags,
   camelize,
@@ -187,7 +188,7 @@ export function createTransformContext(
     cached: [],
     constantCache: new WeakMap(),
     temps: 0,
-    identifiers: Object.create(null),
+    identifiers: new Empty(),
     scopes: {
       vFor: 0,
       vSlot: 0,

packages/compiler-sfc/src/compileScript.ts

@@ -11,7 +11,7 @@ import {
   type SFCScriptBlock,
 } from './parse'
 import type { ParserPlugin } from '@babel/parser'
-import { generateCodeFrame } from '@vue/shared'
+import { Empty, generateCodeFrame } from '@vue/shared'
 import type {
   ArrayPattern,
   CallExpression,
@@ -194,8 +194,8 @@ export function compileScript(
 
   // metadata that needs to be returned
   // const ctx.bindingMetadata: BindingMetadata = {}
-  const scriptBindings: Record<string, BindingTypes> = Object.create(null)
-  const setupBindings: Record<string, BindingTypes> = Object.create(null)
+  const scriptBindings: Record<string, BindingTypes> = new Empty()
+  const setupBindings: Record<string, BindingTypes> = new Empty()
 
   let defaultExport: Node | undefined
   let hasAwait = false

packages/compiler-sfc/src/script/context.ts

@@ -1,6 +1,6 @@
 import type { CallExpression, Node, ObjectPattern, Program } from '@babel/types'
 import type { SFCDescriptor } from '../parse'
-import { generateCodeFrame, isArray } from '@vue/shared'
+import { Empty, generateCodeFrame, isArray } from '@vue/shared'
 import { type ParserPlugin, parse as babelParse } from '@babel/parser'
 import type { ImportBinding, SFCScriptCompileOptions } from '../compileScript'
 import type { PropsDestructureBindings } from './defineProps'
@@ -28,7 +28,7 @@ export class ScriptCompileContext {
   // import / type analysis
   scope?: TypeScope
   globalScopes?: TypeScope[]
-  userImports: Record<string, ImportBinding> = Object.create(null)
+  userImports: Record<string, ImportBinding> = new Empty()
 
   // macros presence check
   hasDefinePropsCall = false
@@ -46,7 +46,7 @@ export class ScriptCompileContext {
   propsRuntimeDecl: Node | undefined
   propsTypeDecl: Node | undefined
   propsDestructureDecl: ObjectPattern | undefined
-  propsDestructuredBindings: PropsDestructureBindings = Object.create(null)
+  propsDestructuredBindings: PropsDestructureBindings = new Empty()
   propsDestructureRestId: string | undefined
   propsRuntimeDefaults: Node | undefined
 
@@ -56,7 +56,7 @@ export class ScriptCompileContext {
   emitDecl: Node | undefined
 
   // defineModel
-  modelDecls: Record<string, ModelDecl> = Object.create(null)
+  modelDecls: Record<string, ModelDecl> = new Empty()
 
   // defineOptions
   optionsRuntimeDecl: Node | undefined

packages/compiler-sfc/src/script/definePropsDestructure.ts

@@ -19,7 +19,7 @@ import {
   unwrapTSNode,
   walkFunctionParams,
 } from '@vue/compiler-dom'
-import { genPropsAccessExp } from '@vue/shared'
+import { Empty, genPropsAccessExp } from '@vue/shared'
 import { isCallOf, resolveObjectKey } from './utils'
 import type { ScriptCompileContext } from './context'
 import { DEFINE_PROPS } from './defineProps'
@@ -103,12 +103,12 @@ export function transformDestructuredProps(
     return
   }
 
-  const rootScope: Scope = Object.create(null)
+  const rootScope: Scope = new Empty()
   const scopeStack: Scope[] = [rootScope]
   let currentScope: Scope = rootScope
   const excludedIds = new WeakSet<Identifier>()
   const parentStack: Node[] = []
-  const propsLocalToPublicMap: Record<string, string> = Object.create(null)
+  const propsLocalToPublicMap: Record<string, string> = new Empty()
 
   for (const key in ctx.propsDestructuredBindings) {
     const { local } = ctx.propsDestructuredBindings[key]

packages/compiler-sfc/src/script/resolveType.ts

@@ -34,7 +34,7 @@ import {
 } from './utils'
 import { type ScriptCompileContext, resolveParserPlugins } from './context'
 import type { ImportBinding, SFCScriptCompileOptions } from '../compileScript'
-import { capitalize, hasOwn } from '@vue/shared'
+import { Empty, capitalize, hasOwn } from '@vue/shared'
 import { parse as babelParse } from '@babel/parser'
 import { parse } from '../parse'
 import { createCache } from '../cache'
@@ -111,14 +111,14 @@ export class TypeScope {
     public filename: string,
     public source: string,
     public offset: number = 0,
-    public imports: Record<string, Import> = Object.create(null),
-    public types: Record<string, ScopeTypeNode> = Object.create(null),
-    public declares: Record<string, ScopeTypeNode> = Object.create(null),
+    public imports: Record<string, Import> = new Empty(),
+    public types: Record<string, ScopeTypeNode> = new Empty(),
+    public declares: Record<string, ScopeTypeNode> = new Empty(),
   ) {}
   isGenericScope = false
-  resolvedImportSources: Record<string, string> = Object.create(null)
-  exportedTypes: Record<string, ScopeTypeNode> = Object.create(null)
-  exportedDeclares: Record<string, ScopeTypeNode> = Object.create(null)
+  resolvedImportSources: Record<string, string> = new Empty()
+  exportedTypes: Record<string, ScopeTypeNode> = new Empty()
+  exportedDeclares: Record<string, ScopeTypeNode> = new Empty()
 }
 
 export interface MaybeWithScope {
@@ -231,7 +231,7 @@ function innerResolveTypeElements(
           resolved.typeParameters &&
           node.typeParameters
         ) {
-          typeParams = Object.create(null)
+          typeParams = new Empty()
           resolved.typeParameters.params.forEach((p, i) => {
             let param = typeParameters && typeParameters[p.name]
             if (!param) param = node.typeParameters!.params[i]
@@ -1442,7 +1442,7 @@ function attachNamespace(
 }
 
 export function recordImports(body: Statement[]): Record<string, Import> {
-  const imports: TypeScope['imports'] = Object.create(null)
+  const imports: TypeScope['imports'] = new Empty()
   for (const s of body) {
     recordImport(s, imports)
   }

packages/compiler-sfc/src/style/pluginScoped.ts

@@ -7,12 +7,13 @@ import {
 } from 'postcss'
 import selectorParser from 'postcss-selector-parser'
 import { warn } from '../warn'
+import { Empty } from '@vue/shared'
 
 const animationNameRE = /^(-\w+-)?animation-name$/
 const animationRE = /^(-\w+-)?animation$/
 
 const scopedPlugin: PluginCreator<string> = (id = '') => {
-  const keyframes = Object.create(null)
+  const keyframes = new Empty()
   const shortId = id.replace(/^data-v-/, '')
 
   return {

packages/runtime-core/src/apiCreateApp.ts

@@ -22,7 +22,7 @@ import { warn } from './warning'
 import { type VNode, cloneVNode, createVNode } from './vnode'
 import type { RootHydrateFunction } from './hydration'
 import { devtoolsInitApp, devtoolsUnmountApp } from './devtools'
-import { NO, extend, isFunction, isObject } from '@vue/shared'
+import { Empty, NO, extend, isFunction, isObject } from '@vue/shared'
 import { version } from '.'
 import { installAppCompatProperties } from './compat/global'
 import type { NormalizedPropsOptions } from './componentProps'
@@ -234,7 +234,7 @@ export function createAppContext(): AppContext {
     mixins: [],
     components: {},
     directives: {},
-    provides: Object.create(null),
+    provides: new Empty(),
     optionsCache: new WeakMap(),
     propsCache: new WeakMap(),
     emitsCache: new WeakMap(),

packages/runtime-core/src/compat/compatConfig.ts

@@ -1,4 +1,4 @@
-import { extend, hasOwn, isArray, isFunction } from '@vue/shared'
+import { Empty, extend, hasOwn, isArray, isFunction } from '@vue/shared'
 import {
   type Component,
   type ComponentInternalInstance,
@@ -425,8 +425,8 @@ export const deprecationData: Record<DeprecationTypes, DeprecationData> = {
   },
 }
 
-const instanceWarned: Record<string, true> = Object.create(null)
-const warnCount: Record<string, number> = Object.create(null)
+const instanceWarned: Record<string, true> = new Empty()
+const warnCount: Record<string, number> = new Empty()
 
 // test only
 let warningEnabled = true

packages/runtime-core/src/compat/global.ts

@@ -7,6 +7,7 @@ import {
   trigger,
 } from '@vue/reactivity'
 import {
+  Empty,
   NOOP,
   extend,
   invokeArrayFns,
@@ -259,7 +260,7 @@ export function createCompatVue(
       mergeBase[key] = isArray(superValue)
         ? superValue.slice()
         : isObject(superValue)
-          ? extend(Object.create(null), superValue)
+          ? extend(new Empty(), superValue)
           : superValue
     }
 
@@ -640,7 +641,7 @@ function defineReactive(obj: any, key: string, val: any) {
   if (i && obj === i.proxy) {
     // target is a Vue instance - define on instance.ctx
     defineReactiveSimple(i.ctx, key, val)
-    i.accessCache = Object.create(null)
+    i.accessCache = new Empty()
   } else if (isReactive(obj)) {
     obj[key] = val
   } else {

packages/runtime-core/src/compat/instanceEventEmitter.ts

@@ -1,4 +1,4 @@
-import { isArray } from '@vue/shared'
+import { Empty, isArray } from '@vue/shared'
 import type { ComponentInternalInstance } from '../component'
 import { ErrorCodes, callWithAsyncErrorHandling } from '../errorHandling'
 import { DeprecationTypes, assertCompatEnabled } from './compatConfig'
@@ -18,7 +18,7 @@ export function getRegistry(
 ): EventRegistry {
   let events = eventRegistryMap.get(instance)
   if (!events) {
-    eventRegistryMap.set(instance, (events = Object.create(null)))
+    eventRegistryMap.set(instance, (events = new Empty()))
   }
   return events!
 }
@@ -69,7 +69,7 @@ export function off(
   const vm = instance.proxy
   // all
   if (!event) {
-    eventRegistryMap.set(instance, Object.create(null))
+    eventRegistryMap.set(instance, new Empty())
     return vm
   }
   // array of events

packages/runtime-core/src/component.ts

@@ -61,6 +61,7 @@ import {
 } from './componentEmits'
 import {
   EMPTY_OBJ,
+  Empty,
   type IfAny,
   NOOP,
   ShapeFlags,
@@ -847,7 +848,7 @@ function setupStatefulComponent(
     }
   }
   // 0. create render proxy property access cache
-  instance.accessCache = Object.create(null)
+  instance.accessCache = new Empty()
   // 1. create public instance / render proxy
   instance.proxy = new Proxy(instance.ctx, PublicInstanceProxyHandlers)
   if (__DEV__) {

packages/runtime-core/src/componentOptions.ts

@@ -9,6 +9,7 @@ import {
   currentInstance,
 } from './component'
 import {
+  Empty,
   type LooseRequired,
   NOOP,
   type Prettify,
@@ -503,7 +504,7 @@ enum OptionTypes {
 }
 
 function createDuplicateChecker() {
-  const cache = Object.create(null)
+  const cache = new Empty()
   return (type: OptionTypes, key: string) => {
     if (cache[key]) {
       warn(`${type} property "${key}" is already defined in ${cache[key]}.`)
@@ -1079,7 +1080,7 @@ function mergeAsArray<T = Function>(to: T[] | T | undefined, from: T | T[]) {
 }
 
 function mergeObjectOptions(to: Object | undefined, from: Object | undefined) {
-  return to ? extend(Object.create(null), to, from) : from
+  return to ? extend(new Empty(), to, from) : from
 }
 
 function mergeEmitsOrPropsOptions(
@@ -1099,7 +1100,7 @@ function mergeEmitsOrPropsOptions(
       return [...new Set([...to, ...from])]
     }
     return extend(
-      Object.create(null),
+      new Empty(),
       normalizePropsOrEmits(to),
       normalizePropsOrEmits(from ?? {}),
     )
@@ -1114,7 +1115,7 @@ function mergeWatchOptions(
 ) {
   if (!to) return from
   if (!from) return to
-  const merged = extend(Object.create(null), to)
+  const merged = extend(new Empty(), to)
   for (const key in from) {
     merged[key] = mergeAsArray(to[key], from[key])
   }

packages/runtime-core/src/componentProps.ts

@@ -8,6 +8,7 @@ import {
 import {
   EMPTY_ARR,
   EMPTY_OBJ,
+  Empty,
   type IfAny,
   PatchFlags,
   camelize,
@@ -197,7 +198,7 @@ export function initProps(
   const props: Data = {}
   const attrs: Data = createInternalObject()
 
-  instance.propsDefaults = Object.create(null)
+  instance.propsDefaults = new Empty()
 
   setFullProps(instance, rawProps, props, attrs)
 

packages/runtime-core/src/componentPublicInstance.ts

@@ -14,6 +14,7 @@ import {
 } from './apiWatch'
 import {
   EMPTY_OBJ,
+  Empty,
   type IfAny,
   NOOP,
   type Prettify,
@@ -365,7 +366,7 @@ const getPublicInstance = (
 export const publicPropertiesMap: PublicPropertiesMap =
   // Move PURE marker to new line to workaround compiler discarding it
   // due to type annotation
-  /*@__PURE__*/ extend(Object.create(null), {
+  /*@__PURE__*/ extend(new Empty(), {
     $: i => i,
     $el: i => i.vnode.el,
     $data: i => i.data,

packages/runtime-core/src/components/BaseTransition.ts

@@ -16,7 +16,7 @@ import { warn } from '../warning'
 import { isKeepAlive } from './KeepAlive'
 import { toRaw } from '@vue/reactivity'
 import { ErrorCodes, callWithAsyncErrorHandling } from '../errorHandling'
-import { PatchFlags, ShapeFlags, isArray, isFunction } from '@vue/shared'
+import { Empty, PatchFlags, ShapeFlags, isArray, isFunction } from '@vue/shared'
 import { onBeforeUnmount, onMounted } from '../apiLifecycle'
 import { isTeleport } from './Teleport'
 import type { RendererElement } from '../renderer'
@@ -303,7 +303,7 @@ function getLeavingNodesForType(
   const { leavingVNodes } = state
   let leavingVNodesCache = leavingVNodes.get(vnode.type)!
   if (!leavingVNodesCache) {
-    leavingVNodesCache = Object.create(null)
+    leavingVNodesCache = new Empty()
     leavingVNodes.set(vnode.type, leavingVNodesCache)
   }
   return leavingVNodesCache

packages/runtime-dom/src/apiCustomElement.ts

@@ -33,6 +33,7 @@ import {
   warn,
 } from '@vue/runtime-core'
 import {
+  Empty,
   camelize,
   extend,
   hasOwn,
@@ -373,9 +374,7 @@ export class VueElement
             if (key in this._props) {
               this._props[key] = toNumber(this._props[key])
             }
-            ;(numberProps || (numberProps = Object.create(null)))[
-              camelize(key)
-            ] = true
+            ;(numberProps || (numberProps = new Empty()))[camelize(key)] = true
           }
         }
       }