Conditionally insert elements in array when using spread operator
npm install insert-ifConditionally add elements to array using spread operators
```javascript
import iif from 'insert-if';
const arr = [
'a',
'b',
// eager evaluation (only use for literal values never for computed deep properties)
...iif(isCForCat(), 'c'),
// on-demand evaluation (safer for deep object properties as it prevents reference errors)
...iif(isThemeEnabled(), () => settings.theme.color),
'd'
];
console.log(arr);
// > Array ['a', 'b', 'c', 'blue', 'd']