Added Rectangle.js and Rectangle.test.js to "Geometry" and it's "test" Directories

Geometry/Rectangle.js

@@ -0,0 +1,43 @@
+/**
+ * Represents a Rectangle with specified length and width.
+ * Explanation:- https://en.wikipedia.org/wiki/Rectangle
+ */
+export default class Rectangle {
+  /**
+   * Create a new Rectangle instance.
+   *
+   * @param {number} length - The length of the rectangle.
+   * @param {number} width - The width of the rectangle.
+   * @throws {Error} If length or width is less than or equal to 0.
+   */
+  constructor (length, width) {
+    this.length = length
+    this.width = width
+  }
+
+  /**
+   * Calculate the perimeter of the rectangle.
+   *
+   * @returns {number} The perimeter of the rectangle.
+   * @throws {Error} If length or width is less than or equal to 0.
+   */
+  calculatePerimeter () {
+    if (this.length <= 0 || this.width <= 0) {
+      throw new Error('Invalid input. Length and width must be greater than 0.')
+    }
+    return 2 * (this.length + this.width)
+  }
+
+  /**
+   * Calculate the area of the rectangle.
+   *
+   * @returns {number} The area of the rectangle.
+   * @throws {Error} If length or width is less than or equal to 0.
+   */
+  calculateArea () {
+    if (this.length <= 0 || this.width <= 0) {
+      throw new Error('Invalid input. Length and width must be greater than 0.')
+    }
+    return this.length * this.width
+  }
+}

Geometry/Test/Rectangle.test.js

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+import Rectangle from '../Rectangle'
+
+const rectangle = new Rectangle(5, 4)
+
+test('Calculate the area of a rectangle', () => {
+  expect(parseFloat(rectangle.calculateArea().toFixed(2))).toEqual(20.00)
+})
+
+test('Calculate the perimeter of a rectangle', () => {
+  expect(parseFloat(rectangle.calculatePerimeter().toFixed(2))).toEqual(18.00)
+})
+
+test('Invalid input for rectangle', () => {
+  expect(() => new Rectangle(0, 4)).toThrowError('Invalid input. Length and width must be greater than 0.')
+})