fix: Make applyPatches to accept readonly Patch[] (#1094)

* Demonstrate possible regression

* Make `Patch[]` arrays `readonly` on the outer bounds

* Limit the change to `applyPatches`

---------

Co-authored-by: Minh Nguyen <2852660+NMinhNguyen@users.noreply.github.com>

Author: Andarist

__tests__/produce.ts

@@ -8,7 +8,8 @@ import {
 	Immutable,
 	Immer,
 	enableMapSet,
-	enablePatches
+	enablePatches,
+	produceWithPatches
 } from "../src/immer"
 
 enableMapSet()
@@ -162,6 +163,20 @@ it("can apply patches", () => {
 	expect(applyPatches({}, patches)).toEqual({x: 4})
 })
 
+it("can apply readonly patches", () => {
+	const [, patches]: readonly [
+		{
+			x: number
+		},
+		readonly Patch[],
+		readonly Patch[]
+	] = produceWithPatches({x: 3}, d => {
+		d.x++
+	})
+
+	expect(applyPatches({}, patches)).toEqual({x: 4})
+})
+
 describe("curried producer", () => {
 	it("supports rest parameters", () => {
 		type State = {readonly a: 1}

src/core/immerClass.ts

@@ -172,7 +172,7 @@ export class Immer implements ProducersFns {
 		this.useStrictShallowCopy_ = value
 	}
 
-	applyPatches<T extends Objectish>(base: T, patches: Patch[]): T {
+	applyPatches<T extends Objectish>(base: T, patches: readonly Patch[]): T {
 		// If a patch replaces the entire state, take that replacement as base
 		// before applying patches
 		let i: number

src/plugins/patches.ts

@@ -211,7 +211,7 @@ export function enablePatches() {
 		})
 	}
 
-	function applyPatches_<T>(draft: T, patches: Patch[]): T {
+	function applyPatches_<T>(draft: T, patches: readonly Patch[]): T {
 		patches.forEach(patch => {
 			const {path, op} = patch
 

src/utils/plugins.ts

@@ -24,7 +24,7 @@ const plugins: {
 			patches: Patch[],
 			inversePatches: Patch[]
 		): void
-		applyPatches_<T>(draft: T, patches: Patch[]): T
+		applyPatches_<T>(draft: T, patches: readonly Patch[]): T
 	}
 	MapSet?: {
 		proxyMap_<T extends AnyMap>(target: T, parent?: ImmerState): T