Type 'never[]' is missing the following properties

Question

Type 'never[]' is missing the following properties from type

'{ login: string; id: number; node_id: string; avatar_url: string; url: string; }': login, id, node_id, avatar_url, url

I was creating a component that take an ApiUrl and fetch info by axios then set state for useState User and after that i can use that information to do destructurization and use that variables in html

Also, don't repeat yourself just to meet the minimum number of characters. — Code-Apprentice, Feb 24 '23 at 17:28
`userInfo` is an array. You are trying to destructure an array as if it were an object. — kelsny, Feb 24 '23 at 17:32
Related: https://stackoverflow.com/questions/52423842/what-is-not-assignable-to-parameter-of-type-never-error-in-typescript — Code-Apprentice, Feb 24 '23 at 17:40
[Please replace images of code/logs/errors with plaintext versions.](https://meta.stackoverflow.com/a/285557/2887218) — jcalz, Feb 24 '23 at 17:51

Viraj Shah · Answer 1 · 2023-02-24T17:50:11.443

The problem is when you define the userInfo variable. You are using the following code:

const [userInfo, setUserInfo] = useState([]);

Often when we write TypeScript, we take advantage of the powerful compiler. It will implicitly type variables upon declaration. This can be useful when you initialize a variable with a string, number, boolean, or a prototype/class constructor. The downside to this is that, oftentimes, we assign a variable, but never check what data type TypeScript implicitly assigned to it.

In this case, you userInfo variable is implicitly assigned a never[] type. Why? The definition for the useState() function is as follows:

function useState<T>(value: T): [T, StateSetter] { ... }

The StateSetter type is something I made up because I don't know the exact type (but it does not matter for this question)

What you're doing is passing in [] to useState. Since this array has 0 elements, TypeScript will implicitly type this with never[] (meaining that it is an array that will never have any elements. So in this case, T is assigned to never[] so the return type of useState is [never[], StateSetter].

You can modify this by adding a type parameter to useState:

interface UserInfo {
    ...
}

const [userInfo, setUserInfo] = useState<UserInfo[]>([]);

This tells TypeScript what kind of information can be stored in this array (if you were to ever add any elements).

NOTE FOR FUTURE POSTS: Do not include screenshots of your code. They are impossible to read, and people trying to help you cannot copy/paste your code. Include the code as formatted code in your question.

You can accomplish this by using the back-ticks:
This is regular text:
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```javascript
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    ...
}
This is regular text:
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    ...
}

Type 'never[]' is missing the following properties

1 Answers1