tswhy‽

Unlike interfaces, type aliases must have a left hand side and right hand side of a statement, so code like this is invalid syntax:

type Person {
  age: number;
  name: string;
}

Instead it should look like this:

type Person = {
  age: number;
  name: string;
};

Code like this is trying to implicitly return an object with the map function, but is actually invalid syntax:

const items = [["a", 1], ["b", 2]];
const mapped = items.map(([key, value]) => { [key]: value });

Instead, use parenthesis (()) around the return value:

const items = [["a", 1], ["b", 2]];
const mapped = items.map(([key, value]) => ({ [key]: value }));