Micro-optimize Object.getPrototypeOf uses

Author: markerikson

src/core/proxy.ts

@@ -12,6 +12,7 @@ import {
 	AnyArray,
 	Objectish,
 	getCurrentScope,
+	getPrototypeOf,
 	DRAFT_STATE,
 	die,
 	createProxy,
@@ -200,7 +201,7 @@ export const objectTraps: ProxyHandler<ProxyState> = {
 		die(11)
 	},
 	getPrototypeOf(state) {
-		return Object.getPrototypeOf(state.base_)
+		return getPrototypeOf(state.base_)
 	},
 	setPrototypeOf() {
 		die(12)
@@ -259,11 +260,11 @@ function getDescriptorFromProto(
 ): PropertyDescriptor | undefined {
 	// 'in' checks proto!
 	if (!(prop in source)) return undefined
-	let proto = Object.getPrototypeOf(source)
+	let proto = getPrototypeOf(source)
 	while (proto) {
 		const desc = Object.getOwnPropertyDescriptor(proto, prop)
 		if (desc) return desc
-		proto = Object.getPrototypeOf(proto)
+		proto = getPrototypeOf(proto)
 	}
 	return undefined
 }

src/plugins/patches.ts

@@ -11,6 +11,7 @@ import {
 	each,
 	has,
 	getArchtype,
+	getPrototypeOf,
 	isSet,
 	isMap,
 	loadPlugin,
@@ -296,7 +297,7 @@ export function enablePatches() {
 				Array.from(obj.entries()).map(([k, v]) => [k, deepClonePatchValue(v)])
 			)
 		if (isSet(obj)) return new Set(Array.from(obj).map(deepClonePatchValue))
-		const cloned = Object.create(Object.getPrototypeOf(obj))
+		const cloned = Object.create(getPrototypeOf(obj))
 		for (const key in obj) cloned[key] = deepClonePatchValue(obj[key])
 		if (has(obj, immerable)) cloned[immerable] = obj[immerable]
 		return cloned

src/utils/common.ts

@@ -11,6 +11,8 @@ import {
 	die
 } from "../internal"
 
+export const getPrototypeOf = Object.getPrototypeOf
+
 /** Returns true if the given value is an Immer draft */
 /*#__PURE__*/
 export function isDraft(value: any): boolean {
@@ -35,7 +37,7 @@ const objectCtorString = Object.prototype.constructor.toString()
 /*#__PURE__*/
 export function isPlainObject(value: any): boolean {
 	if (!value || typeof value !== "object") return false
-	const proto = Object.getPrototypeOf(value)
+	const proto = getPrototypeOf(value)
 	if (proto === null) {
 		return true
 	}
@@ -144,7 +146,7 @@ export function shallowCopy(base: any, strict: boolean) {
 	if (Array.isArray(base)) return Array.prototype.slice.call(base)
 
 	if (!strict && isPlainObject(base)) {
-		if (!Object.getPrototypeOf(base)) {
+		if (!getPrototypeOf(base)) {
 			const obj = Object.create(null)
 			return Object.assign(obj, base)
 		}
@@ -172,7 +174,7 @@ export function shallowCopy(base: any, strict: boolean) {
 				value: base[key]
 			}
 	}
-	return Object.create(Object.getPrototypeOf(base), descriptors)
+	return Object.create(getPrototypeOf(base), descriptors)
 }
 
 /**