Typescript (or should we say ES) doesn't allow destructuring of null/undefined objects. It throws TypeError.
So, lets say we have something like
let {a,b,c} = D;
where D could be null.
If we need to do conditional destructuring assignment with null-checks then we create boilerplate code for something that was meant to reduce it.
What is the most elegant way of using it in cases like that or should we use destructuring only for guaranteed non-null objects?
You can use an empty object as fallback, and if D is null or undefined the assigned variables will be undefined.
const D = null;
const { a, b, c } = D || {};
console.log(a, b, c);Another option is to use object spread, since spreading null or undefined results in an empty object (see this SO answer).
const D = null;
const { a, b, c } = { ...D };
console.log(a, b, c);If you need to handle nested destructuring, use defaults:
const D = null;
const { a, a: { z } = {}, b, c } = { ...D };
console.log(a, b, c, z);
