使用联合类型

❌ 不要只在一个参数位置编写因类型而异的重载：

❌ Don't write overloads that differ by type in only one argument position:

/* WRONG */
interface Moment {
  utcOffset(): number;
  utcOffset(b: number): Moment;
  utcOffset(b: string): Moment;
}

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/* OK */
interface Moment {
  utcOffset(): number;
  utcOffset(b: number | string): Moment;
}

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function fn(x: string): void;
function fn(x: number): void;
function fn(x: number | string) {
  // When written with separate overloads, incorrectly an error
  // When written with union types, correctly OK
  return moment().utcOffset(x);
}