Using omit can't validate key passed as parameter #5884

BIG293 · 2024-06-12T15:38:21Z

It seems that generic omit overloads prevent the usage of the typed one that connect the object type to the type of keys

import { omit } from 'lodash-es'

interface A {
  a: number;
  b: string;
}

const a: A = {
  a: 1,
  b: '2'
}

omit(a, 'c') // it compiles, but it should not

avivkal · 2024-06-14T13:49:40Z

It seems like the current type is string | number | symbol, you can certainly make it more specific by yourself, for example:
omit<A, keyof A>(a, 'ad') // this will raise a compilation error

BIG293 · 2024-06-14T14:13:20Z

I certainly know that I can do it, but then I cannot use Typescript's type inference adding boilerplate and making that overload useless. It would be enough one overload with any or string | number | symbol as default

avivkal · 2024-06-14T14:33:39Z

I am not sure I understood, do you mean something like this:
omit<keyof A>(a, ['a'])
Or something like this:
omit(a, ['a'])
that will always enforce the type?

BIG293 · 2024-06-14T15:23:59Z

No. The problem is that the omit has three overloads:

        omit<T extends object, K extends PropertyName[]>(
            object: T | null | undefined,
            ...paths: K
        ): Pick<T, Exclude<keyof T, K[number]>>;
        /**
         * @see _.omit
         */
        omit<T extends object, K extends keyof T>(object: T | null | undefined, ...paths: Array<Many<K>>): Omit<T, K>;
        /**
         * @see _.omit
         */
        omit<T extends object>(object: T | null | undefined, ...paths: Array<Many<PropertyName>>): PartialObject<T>;

The problem is that I'd want to use the second one, without explicitly passing the generics parameters, leveraging the TS's type inference. At the moment with this three overload instead you don't have any intellisense and if you pass any key that is not in the object keys it compiles. Therefore this solution is not robust and expose you to risk in case of refactoring of the property names.

NinaRoss1128 · 2024-06-24T06:40:15Z

Where for I omit that

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Using omit can't validate key passed as parameter #5884

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