TS: null is not an array type

Issue

I am trying to conditionally add an object within an array of object. When I am doing it, I get a TS error in my editor saying {name: 'new', age:22} | null is not an array type. Even if I set newAnimal to type any, I still get that error.

const shouldAdd = true;

const newAnimal = {
   name: "new",
   age: 22,
}

const data = [
   {
     name: "dog",
     age: 11
   }, 
   ...(shouldAdd ? [newAnimal] : null),
   {
     name: "cat",
     age: 21,
   }
]

Solution

You're attempting to destructure null as an array. You'll need to use [] instead:

const data = [
   {
     name: "dog",
     age: 11
   }, 
   ...(shouldAdd ? [newAnimal] : []),
   {
     name: "cat",
     age: 21,
   }
]

Answered By - evsheino