isDefined: Return true only if the element is not null or undefined

isDefined.ts

/**
 * Return true only if the element is not null or undefined,
 * use it with `Array.filter` to not only filter nullable values
 * but also to guard the type.
 */
export const isDefined = <T>(argument: T | undefined | null): argument is T => {
  return argument !== undefined && argument !== null;
};