Idea: ts identity npm package

identity.ts

export default class Identity {
  static isNumber(v: unknown): v is number {
    return typeof v === 'number';
  }

  static isString(v: unknown): v is string {
    return typeof v === 'string' || v instanceof String;
  }

  static isNil(v: unknown): boolean {
    return v === null || v === undefined;
  }

  static isNull(v: unknown): v is null {
    return v === null;
  }

  static isUndefined(v: unknown): v is undefined {
    return v === undefined;
  }

  static isBoolean(v: unknown): boolean {
    return typeof v === 'boolean';
  }

  static isObject(v: unknown): v is object {
    return typeof v === 'object' && v !== null;
  }

  static isArray(v: unknown): boolean {
    return Array.isArray(v);
  }

  static isBigInt(v: unknown): v is bigint {
    return typeof v === 'bigint';
  }

  static isDate(v: unknown): v is Date {
    return v instanceof Date;
  }
}