Arrow functions behave inconsistently with classic functions #56067
Description
🔎 Search Terms
Unable to get generic type, arrow function
🕗 Version & Regression Information
- This is a crash
- This problem exists in Nightly version
- This is the behavior in every version I tried
⏯ Playground Link
💻 Code
declare function create<
State extends Record<string, any>,
Data extends Record<string, any>,
Actions extends (state: State, data: Data) => Record<string, any>,
>(args: {
getState: () => State;
actions: Actions;
getData: () => Data;
}): void;
create({
getState() {
return { a: 1 }
},
getData: () => {
return { b: 2 }
},
actions(state, data) {
state
// ^?
data
// ^?
return {
z: 1
}
}
})🙁 Actual behavior
The getState and getData function types need to be consistent. For example, they are both arrow functions or ordinary functions to correctly infer the type. Otherwise, they cannot
🙂 Expected behavior
No matter what type of functions getState and getData are, the types can be correctly inferred in the actions function parameters.
Additional information about the issue
No response