Function generic unmatched: Matching hehavior is difference between arrow functions and normal function

[HoikanChan]

🔎 Search Terms

Function generic unmatched

🕗 Version & Regression Information

• This is marybe bug?
• The versions is 5.4.5

⏯ Playground Link

https://www.typescriptlang.org/play/?ts=5.4.5#code/KYDwDg9gTgLgBDAnmYcDKMCGNgDECuAdgMYwCWEhAPBtsAHxwC8cAFAFBxdwDOAXOiw4ANJ24A6SZigBzfnEyFEAbQC67AJTNGixAG527UJFgJkqAGr5QGaMADyYcpR5UxXWiPdwAshAAm+AA2wDyijCwA3t48QsAA-AKeqAA+bKxaTIzJWmmRbBpJcXAAvgbccAC2+EIUhDyJcABKwMTQ-lSxUGSEMsKCdAQkztTJ9PTl3JUBwaGN0RUVygDWcD1wy8CIEABmvjMhPKoCVjYwdo4jrn6Bhyuq-YTAAG7AUPTeZewlhsbQ8DsiKQ6nBiFBgHRbOC3BVknBQDhCP4eM1Wu1OjBur1+kRloQIAB3Qj0UQVG6zFEI4BIlEtNpQDpdHp9VH0xmY5k4wh4wnEknseisCBOOryU4gKEOEUuGhxfrkw70LTRH7sNr1eCxOzMUHgyHncGsBbcWJ0DJwfLgmD4KCEC1wABG0gATAIAIylUqkqY1bCigT5HrEASsU04N3OgDMmUYYeAEcj4idUGdAGpU17vNNbqEA94KjsIBA84tS3AAPTl3hxEMxtj5ZOuuAekoafqVuAAFQAFmQUVVsMRuwhu6g45My9wO3GBIDhiDzcbJ1wOxUrTa7Q2Xe7ShPlx2Su2qwAhGojvugxQAchg+bLccXd+XXHXtvtjZ3X2fXEPFarin8LtexRYhr1vb8-2rOgA0dbdmy9OAn0WapahcGCgxDOM6zjJMXXTTMkMPT5RFbAwgA

💻 Code

export type StateFunction<State> = (
 s: State,
 ...args: any[]
) => any;

export type VuexStoreOptions<
 State,
 Modules,
> = {
 state?: State | (() => State) | { (): State };
 mutations?: Record<string, StateFunction<State>>;
 modules?: {
 [k in keyof Modules]: VuexStoreOptions<Modules[k], never>
 };
}

export function createStore<
 State extends Record<string, unknown>,
 Modules extends Record<string, Record<string, unknown>>,
>(options: VuexStoreOptions<State, Modules>) {
}

const store = createStore({
 state() { return { bar2: 1 } },
 mutations: { inc: (state123) => state123.bar2++ },
 modules: {
 foo: {
 // state: () => ({ bar2: 1 }), // This match the state;
 // state: function () {
 // return { bar2: 1 };
 // }, // But this can't
 state() {
 return { bar2: 1 };
 }, // and This can't
 // state: { bar2: 1 }, 
 mutations: { inc: (state) => state.bar2++ },

 },
 },
});

🙁 Actual behavior

If use arrow function or obj method function to declare the state in modules.foo

Got error:
'state.bar2' is of type 'unknown'.

But arrow function won't.

🙂 Expected behavior

No matter which one i use to declare the fucntion ( arrow function, method function or just function),
the state can be known in mutations param

Additional information about the issue

No response

[RyanCavanaugh]

See #47599

[typescript-bot]

This issue has been marked as "Duplicate" and has seen no recent activity. It has been automatically closed for house-keeping purposes.