Why Typescript is not throwing error when an empty array value is assigned to a type of array of non empty objects? [duplicate]

Question

let obj: {
    id_1: number;
    id_2: number;
}[] = [];

2 Questions

Array should contain object or objects with both the defined keys id_1 and id_2, but cannot be empty

I am new to TS and cannot understand the above behaviour, someone please help.

herostoky · Accepted Answer · 2022-09-01 11:48:36Z

1

you can create a specific Type to make an "unemptyable" array. Ref here

EDIT : eg if the playground is not working

type NonEmptyArrayTest<T> = [T, ...T[]];
let obj: NonEmptyArrayTest<{
  id_1: number;
  id_2: number;
}>;

answered Sep 1, 2022 at 11:37

herostoky

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You should include the code in the answer itself in case the links stop working in the future