introduce StrictMode enum

__tests__/not-strict-copy.ts

@@ -2,12 +2,13 @@ import {
 	immerable,
 	produce,
 	setUseStrictShallowCopy,
-	setAutoFreeze
+	setAutoFreeze,
+	StrictMode
 } from "../src/immer"
 
 describe.each([true, false, "class_only" as const])(
 	"setUseStrictShallowCopy(true)",
-	(strictMode: boolean | "class_only") => {
+	(strictMode: StrictMode) => {
 		test("keep descriptors, mode: " + strictMode, () => {
 			setUseStrictShallowCopy(strictMode)
 

src/core/immerClass.ts

@@ -31,13 +31,15 @@ interface ProducersFns {
 	produceWithPatches: IProduceWithPatches
 }
 
+export type StrictMode = boolean | "class_only";
+
 export class Immer implements ProducersFns {
 	autoFreeze_: boolean = true
-	useStrictShallowCopy_: boolean | "class_only" = false
+	useStrictShallowCopy_: StrictMode = false
 
 	constructor(config?: {
 		autoFreeze?: boolean
-		useStrictShallowCopy?: boolean | "class_only"
+		useStrictShallowCopy?: StrictMode
 	}) {
 		if (typeof config?.autoFreeze === "boolean")
 			this.setAutoFreeze(config!.autoFreeze)
@@ -166,7 +168,7 @@ export class Immer implements ProducersFns {
 	 *
 	 * By default, immer does not copy the object descriptors such as getter, setter and non-enumrable properties.
 	 */
-	setUseStrictShallowCopy(value: boolean | "class_only") {
+	setUseStrictShallowCopy(value: StrictMode) {
 		this.useStrictShallowCopy_ = value
 	}
 

src/immer.ts

@@ -18,7 +18,8 @@ export {
 	NOTHING as nothing,
 	DRAFTABLE as immerable,
 	freeze,
-	Objectish
+	Objectish,
+	StrictMode
 } from "./internal"
 
 const immer = new Immer()

src/utils/common.ts

@@ -8,7 +8,8 @@ import {
 	AnySet,
 	ImmerState,
 	ArchType,
-	die
+	die,
+	StrictMode
 } from "../internal"
 
 export const getPrototypeOf = Object.getPrototypeOf
@@ -140,7 +141,7 @@ export function latest(state: ImmerState): any {
 }
 
 /*#__PURE__*/
-export function shallowCopy(base: any, strict: boolean | "class_only") {
+export function shallowCopy(base: any, strict: StrictMode) {
 	if (isMap(base)) {
 		return new Map(base)
 	}