DateRange

class DateRange {
  private startDate: Date;
  private endDate: Date;
 
  constructor(startDate: Date, endDate: Date) {
    if (startDate > endDate) {
      throw new Error(
        "Invalid date range. Start date should be before or equal to the end date."
      );
    }
    this.startDate = startDate;
    this.endDate = endDate;
  }
 
  equals(other: DateRange): boolean {
    return (
      this.startDate.getTime() === other.startDate.getTime() &&
      this.endDate.getTime() === other.endDate.getTime()
    );
  }
 
  toString(): string {
    return `Start Date: ${this.startDate.toISOString()}, End Date: ${this.endDate.toISOString()}`;
  }
}
 
// Example usage
const startDate = new Date("2023-01-01");
const endDate = new Date("2023-12-31");
const dateRange = new DateRange(startDate, endDate);
console.log(dateRange.toString()); // Start Date: 2023-01-01T00:00:00.000Z, End Date: 2023-12-31T00:00:00.000Z

import { DateRange } from "./DateRange"; // Adjust the import path as per your project structure
 
describe("DateRange", () => {
  describe("constructor", () => {
    it("should create a DateRange instance with a valid start and end date", () => {
      const startDate = new Date("2023-01-01");
      const endDate = new Date("2023-12-31");
      const dateRange = new DateRange(startDate, endDate);
      expect(dateRange).toBeDefined();
    });
 
    it("should throw an error for an end date earlier than the start date", () => {
      const startDate = new Date("2023-12-31");
      const endDate = new Date("2023-01-01");
      expect(() => new DateRange(startDate, endDate)).toThrow();
    });
  });
 
  describe("equals", () => {
    it("should return true when comparing two DateRange instances with the same start and end date", () => {
      const startDate = new Date("2023-01-01");
      const endDate = new Date("2023-12-31");
      const dateRange1 = new DateRange(startDate, endDate);
      const dateRange2 = new DateRange(startDate, endDate);
      expect(dateRange1.equals(dateRange2)).toBe(true);
    });
 
    it("should return false when comparing two DateRange instances with different start or end date", () => {
      const startDate1 = new Date("2023-01-01");
      const endDate1 = new Date("2023-12-31");
      const dateRange1 = new DateRange(startDate1, endDate1);
 
      const startDate2 = new Date("2023-01-01");
      const endDate2 = new Date("2023-06-30");
      const dateRange2 = new DateRange(startDate2, endDate2);
      expect(dateRange1.equals(dateRange2)).toBe(false);
    });
  });
 
  describe("toString", () => {
    it("should return the string representation of the DateRange", () => {
      const startDate = new Date("2023-01-01");
      const endDate = new Date("2023-12-31");
      const dateRange = new DateRange(startDate, endDate);
      expect(dateRange.toString()).toBe(
        `Start Date: ${startDate.toISOString()}, End Date: ${endDate.toISOString()}`
      );
    });
  });
});