To define an array with conditional elements with JavaScript, we use the ternary operator.
For instance, we write
const items = ["foo", ...(true ? ["bar"] : []), ...(false ? ["falsy"] : [])];
console.log(items);
to spread the entries in ["bar"] since the condition is true.
And we spread the empty array into the array since false is before the 2nd ternary operator.
