zustand/middlerware/immer stopped working since v5.0.4 (React Native only)

[gabimoncha]

I'm currently getting the following error when using zustand/middlerware/immer with Maps

The thrown error is:

[Immer] The plugin for 'MapSet' has not been loaded into Immer. To enable the plugin, import and call `enableMapSet()` when initializing your application.

I've managed to pin point the issue to v5.0.4, the one that patched the library for react-native
v5.0.3...v5.0.4

It seems that zustand immer doesn't apply the enableMapSet() when called through immer

This is a small working demo that works with zustand 5.0.3, but fails when version is greater or equal to 5.0.4

import { enableMapSet, produce } from "immer";
import { create } from "zustand";
import { immer } from "zustand/middleware/immer";

enableMapSet();

// Test with a simple Map
try {
	console.log("Testing with Map...");
	const testMap = new Map<string, any>();
	testMap.set("test", { value: 1 });

	const newMap = produce(testMap, (draft) => {
		draft.set("test", { value: 2 });
	});

	console.log("Map test successful:", newMap.get("test").value === 2);
} catch (error) {
	console.error("Map test failed:", error);
}

// Test with Zustand store using Map
try {
	console.log("Testing with Zustand store...");

	interface TestState {
		testMap: Map<string, any>;
		updateMap: (key: string, value: any) => void;
	}

	const useTestStore = create<TestState>()(
		immer((set) => ({
			testMap: new Map([["initial", { count: 0 }]]),
			updateMap: (key, value) =>
				set((state) => {
					state.testMap.set(key, value);
				}),
		})),
	);

	const { updateMap } = useTestStore.getState();
	updateMap("test", { count: 5 });

	console.log(
		"Zustand test successful:",
		useTestStore.getState().testMap.get("test").count === 5,
	);
} catch (error) {
	console.error("Zustand test failed:", error);
}

console.log("===== IMMER TEST COMPLETED =====");

[dai-shi]

Thanks for reporting.

So, #3087 changed the behavior according to your investigation.
It sounds like a dual-module issue.
Does the problem happen only with RN, or does it happen without RN too?

[gabimoncha]

@dai-shi yes, it seems it only affects RN

[dai-shi]

Thanks for confirming.

I think we need some help from people who are more familiar with RN bundling behavior.

https://app.unpkg.com/immer@10.1.1/files/package.json#L16

Immer has this, which may confuse RN bundler.

[gabimoncha]

thanks a ton @dai-shi. You are right, their package.json config was incorrect.
i removed the react-native line and changed the exports to this and now it works. Will patch the lib for now and make a PR for immer

	"exports": {
		"./package.json": "./package.json",
		".": {
			"react-native": {
				"types": "./dist/immer.d.ts",
				"default": "./dist/immer.legacy-esm.js"
			},
			"import": {
				"types": "./dist/immer.d.ts",
				"default": "./dist/immer.mjs"
			},
			"require": {
				"types": "./dist/immer.d.ts",
				"default": "./dist/cjs/index.js"
			}
		}
	},

[gabimoncha]

@dai-shi new version of immer contains the correct react native export field, in case you want to lock it
immerjs/immer#1159

[dbritto-dev]

@gabimoncha immer is a peer deep so is up to user

[myrj27]

Yes

…

On Fri, 15 Aug 2025, 1:21 pm gabimoncha, ***@***.***> wrote: thanks a ton @dai-shi <https://github.com/dai-shi>. You are right, their package.json config was incorrect. i removed the react-native line and changed the exports to this and now it works. Will patch the lib for now and make a PR for immer "exports": { "./package.json": "./package.json", ".": { "react-native": { "types": "./dist/immer.d.ts", "default": "./dist/immer.legacy-esm.js" }, "import": { "types": "./dist/immer.d.ts", "default": "./dist/immer.mjs" }, "require": { "types": "./dist/immer.d.ts", "default": "./dist/cjs/index.js" } } }, — Reply to this email directly, view it on GitHub <#3211 (reply in thread)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/BUF75NVDXZO4I7KUKTYE4OD3NWYDFAVCNFSM6AAAAACD4RKPOKVHI2DSMVQWIX3LMV43URDJONRXK43TNFXW4Q3PNVWWK3TUHMYTIMJRGUYDGMQ> . You are receiving this because you are subscribed to this thread.Message ID: ***@***.***>