Trying to migrate to v4 but hitting issue with mocking

[httpete]

I was using the mocks/zustand.ts that contained the boilerplate from the doc, but now I get TypeError: store.getState is not a function

import { act } from 'react-dom/test-utils';
import actualCreate from 'zustand';

// a variable to hold reset functions for all stores declared in the app
const storeResetFns = new Set();

// when creating a store, we get its initial state, create a reset function and add it in the set
const create = createState => {
  const store = actualCreate(createState);
  const initialState = store().getState();
  storeResetFns.add(() => store.setState(initialState, true));

  return store;
};

// Reset all stores after each test run
afterEach(() => {
  act(() => storeResetFns.forEach(resetFn => resetFn()));
});

export default create;

[dai-shi]

Hm, not sure, but does this help?

const store = actualCreate(createState || () => ({}));

[devanshj]

Guessing but you'll probably have to change your mocked create to allow the curried usage...

const create = f =>
  f === undefined ? createImpl : createImpl(f)

const createImpl = createState => {
  const store = actualCreate(createState)
  const initialState = store().getState()
  storeResetFns.add(() => store.setState(initialState, true))

  return store
}

[httpete]

OK Ill try soon thank you. I absolutely love the simplicity of Zustand 3, but I am finding that Zustand 4 just seems to be harder to use and I am not sure of the benefit. I really like to keep up to date, but my first shot at migrating us to 4rc1 didn't go too well. I will try again. When do you foresee a final 4?

[dai-shi]

When do you foresee a final 4?

I will merge #953, #1029, #1051, when they are ready, and release rc.2. If we don't get any issues with it, we will finalize it.

[httpete]

Thank you @dai-shi I will try right away and provide feedback.

[devanshj]

I am not sure of the benefit.

You can see the diff of middlewareTypes.test.tsx between v3.6.9 and v4. Here's an excerpt...

Before (v3.6.9):

const useStore = create<
  CounterState,
  SetState<CounterState>,
  GetState<CounterState>,
  StoreApiWithSubscribeWithSelector<CounterState> &
    StoreApiWithPersist<CounterState> &
    StoreApiWithDevtools<CounterState>
>(
  devtools(
    subscribeWithSelector(
      persist(
        (set, get) => ({
          count: 0,
          inc: () => set({ count: get().count + 1 }, false),
        }),
        { name: 'count' }
      )
    ),
    { name: 'prefix' }
  )
)

After (v4.0.0-rc1):

const useStore = create<CounterState>()(
  devtools(
    subscribeWithSelector(
      persist(
        (set, get) => ({
          count: 0,
          inc: () => set({ count: get().count + 1 }, false),
        }),
        { name: 'count' }
      )
    ),
    { name: 'prefix' }
  )
)

my first shot at migrating us to 4rc1 didn't go too well.

Btw there's a migration guide if you missed it. If you follow it you will have mostly no problems. And there is no breaking change in the runtime code whatsoever.

Also looks like you were not using TypeScript for your mocking code or else the bug would have been caught. For instance you were writing create()(...) ie passing undefined to create but not handling it.

I will merge https://github.com/pmndrs/zustand/pull/953, https://github.com/pmndrs/zustand/pull/1029, https://github.com/pmndrs/zustand/pull/1051, when they are ready, and release rc.2.

Let's also wait for my PR to fix #1046, I'll open soon.

[dai-shi]

Let's also wait for my PR to fix #1046, I'll open soon.

@devanshj Is it coming soon? Everything else is ready, so I can release rc.2.

[devanshj]

The PR was for option 2, but now that we went with option 1, we don't need it and #1090 suffices.

[dai-shi]

Cool. Thanks.

[httpete]

Thanks all, as long as the docs that have that snip of "how to mock zustand" is updated when you release, I don't think others will be tripped on this.

https://github.com/pmndrs/zustand/wiki/Testing

[dai-shi]

We want to create new testing guide #968, but it's stalled. It will not be done soon. Could you update the wiki page as much as you can?

[httpete]

Hm, not sure, but does this help?

const store = actualCreate(createState || () => ({}));

It doesn't. I am finding now that Zustand 4 works perfectly in the browser, but my zustand mock isn't resetting properly. I am trying, with the ideas from @devanshj to accommodate the currying but I haven't found it yet.

[httpete]

I had to give up, I actually determined that I don't need (or want) because all of our components are wrapped in a unique ZustandContext and instantiated fresh with each test. I don't have the problem of a global state that needs resetting. So I am punting.

I reviewed the testing guide, but as you say it is raw. The barest min would at least have the Testing Wiki have a starter snip with something that works with Z4.

[arvinxx]

@dai-shi I try to mirgration from v3 to v4, but failed too…

How to fix the curried usage?

const create = f =>
  f === undefined ? createImpl : createImpl(f)

const createImpl = createState => {
  const store = actualCreate(createState)
  const initialState = store().getState()
  storeResetFns.add(() => store.setState(initialState, true))

  return store
}

I have tried this but didn't work.

[dai-shi]

How to fix the curried usage?

Hm, it has to be something like this?

const create = () => createState => {
  const store = actualCreate(createState)
  const initialState = store.getState()
  storeResetFns.add(() => store.setState(initialState, true))
  return store
}

I reviewed the testing guide, but as you say it is raw. The barest min would at least have the Testing Wiki have a starter snip with something that works with Z4.

We need someone to help fixing the doc.

[arvinxx]

How to fix the curried usage?

Hm, it has to be something like this?

const create = () => createState => {
  const store = actualCreate(createState)
  const initialState = store.getState()
  storeResetFns.add(() => store.setState(initialState, true))
  return store
}

I reviewed the testing guide, but as you say it is raw. The barest min would at least have the Testing Wiki have a starter snip with something that works with Z4.

We need someone to help fixing the doc.

don't work with createContext usage.

[dai-shi]

don't work with createContext usage.

I'm not familiar with testing with React context, but do people inject store with context, don't they?

[razzeee]

I'm getting the same error as @httpete when using import actualCreate from 'zustand' inspite of us using jest.

If I use const actualCreate = jest.requireActual('zustand') // if using jest like the docs mention I end up with TypeError: actualCreate is not a function

[gfox1984]

I had the same error as @httpete and @razzeee, but with the change @dai-shi suggested in his previous comment, it's working fine now.

Im using Jest and my file is called zustand.ts (not .js, unlike the docs suggest) and it is located in the __mocks__ folder (at the root of my tests folder, where I've put all my tests). The content is:

import { act } from 'react-dom/test-utils';
import actualCreate from 'zustand';

// a variable to hold reset functions for all stores declared in the app
const storeResetFns = new Set<() => void>();

// when creating a store, we get its initial state, create a reset function and add it in the set
const create = () => (createState) => {
  const store = actualCreate(createState);
  const initialState = store.getState();
  storeResetFns.add(() => store.setState(initialState, true));
  return store;
};

// Reset all stores after each test run
beforeEach(() => {
  act(() => storeResetFns.forEach((resetFn) => resetFn()));
});

export default create;

I think the docs need an update...

EDIT: I also changed Set to Set<() => void> to avoid typescript error when using resetFn.

[arvinxx]

How to fix the curried usage?

Hm, it has to be something like this?

const create = () => createState => {
  const store = actualCreate(createState)
  const initialState = store.getState()
  storeResetFns.add(() => store.setState(initialState, true))
  return store
}

I reviewed the testing guide, but as you say it is raw. The barest min would at least have the Testing Wiki have a starter snip with something that works with Z4.

We need someone to help fixing the doc.

don't work with createContext usage.

I have fix the test by export useStore

import actualCreate from 'zustand';
import { act } from '@testing-library/react-hooks';

// a variable to hold reset functions for all stores declared in the app
const storeResetFns = new Set();

// when creating a store, we get its initial state, create a reset function and add it in the set
-const create = (createState) => {
+const createImpl = (createState) => {
  console.log(createState);
  const store = actualCreate(createState);
  const initialState = store.getState();
  storeResetFns.add(() => store.setState(initialState, true));
  return store;
};

// Reset all stores after each test run
afterEach(() => {
  act(() => storeResetFns.forEach((resetFn) => resetFn()));
});

+ const create = (f) => (f === undefined ? createImpl : createImpl(f));

export default create;

+ export { useStore } from 'zustand';

[tfreitas90]

Hey, I had the same problem than OP and I fixed with the following: The difference is, instead of const create = createState => {...} it should be: const create = () => createState => {...}.

How to fix the curried usage?

Hm, it has to be something like this?

const create = () => createState => {
  const store = actualCreate(createState)
  const initialState = store.getState()
  storeResetFns.add(() => store.setState(initialState, true))
  return store
}

I reviewed the testing guide, but as you say it is raw. The barest min would at least have the Testing Wiki have a starter snip with something that works with Z4.

We need someone to help fixing the doc.

Thanks!

[kandrelczyk]

Hi, hit the same issue and resolved it by migrating my project to jotai.

[sewera]

I believe this issue is resolved now with const create = () => createState => {...}, as per this comment, so I'll close it now.

For reference, I'll put the relevant docs links:

• TypeScript Guide,
• TypeScript usage in Testing Guide

If a similar case happens in the future, this issue can be re-opened or, better yet, referenced.

[tom2strobl]

I know this is an older+closed issue, but for others struggling to get mock-resets to work properly I still want to mention that what @devanshj said in https://github.com/pmndrs/zustand/issues/1059#issuecomment-1175974777 was necessary for us since we use middleware and sometimes the curried, sometimes the regular invocation.

We're using ts/jest/TLR and saw great results like so:

import { act } from '@testing-library/react'
import { create as createType, StateCreator } from 'zustand'

const zustand = jest.requireActual('zustand')
const actualCreate: typeof createType = zustand.create

// a variable to hold reset functions for all stores declared in the app
const storeResetFns = new Set<() => void>()

// when creating a store, we get its initial state, create a reset function and add it in the set
const createImpl = <S>(createState: StateCreator<S>) => {
  const store = actualCreate<S>(createState)
  const initialState = store.getState()
  storeResetFns.add(() => store.setState(initialState, true))
  return store
}

// support currying
export function create<S>(f: StateCreator<S>) {
  return f === undefined ? createImpl : createImpl(f)
}

// Reset all stores after each test run
beforeEach(() => {
  act(() => storeResetFns.forEach((resetFn) => resetFn()))
})

Note that the docs still tell users to only support the uncurried version, which might cause trouble for some (like us).