Using never to return from Area::getRoomById(...)

[rogersm]

Folks,

why are we doing typing the return from Area::getRoomById with never?

getRoomById(id: string): Room | never {
    const room = this.rooms.get(id);
    if (!room) {
        throw new Error(`Area did not find Room with id: [${id}]`);
    }
    return room;
}

Never should be used for:

• A function never returns (e.g. if the function body has while(true){})
• A function always throws (e.g. in function foo(){throw new Error('Not Implemented')} the return type of foo is never)

And in this case we return (room) or we may (but not always) thrown an Error.

Shouldn't this be:

getRoomById(id:string): Room { ... }

[seanohue]

I've seen never used to annotate the fact that the method returns an error but if that's an antipattern we can remove it

[rogersm]

That would be my recommendation.

Typescript Deep Dive Book describes the use of never in detail.

[seanohue]

Makes sense to me -- let's ditch it, then.

On Mon, May 17, 2021 at 2:57 PM Roger Sen @.***> wrote:

That would be my recommendation.

Typescript Deep Dive Book describes the use of never in detail. https://basarat.gitbook.io/typescript/type-system/never

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