feat: add geometry rectangle

Geometry/Rectangle.js

@@ -0,0 +1,85 @@
+/**
+ * This class represents a rectangle and provides methods to calculate its perimeter and area.
+ * @see {@link https://en.wikipedia.org/wiki/Rectangle}
+ */
+export default class Rectangle {
+  /** @private */
+  #length
+
+  /** @private */
+  #breadth
+
+  /**
+   * Creates a new Rectangle instance.
+   * @constructor
+   * @param {number} length - The length of the rectangle.
+   * @param {number} breadth - The breadth of the rectangle.
+   * @throws {Error} Will throw an error if length or breadth is not a positive number.
+   */
+  constructor(length, breadth) {
+    this.#validateDimension(length, 'length')
+    this.#validateDimension(breadth, 'breadth')
+    this.#length = length
+    this.#breadth = breadth
+  }
+
+  /**
+   * Validates that a dimension is a positive number.
+   * @private
+   * @param {number} value - The value to validate.
+   * @param {string} name - The name of the dimension (for error reporting).
+   * @throws {Error} Will throw an error if the value is not a positive number.
+   */
+  #validateDimension(value, name) {
+    if (typeof value !== 'number' || isNaN(value) || value <= 0) {
+      throw new Error(`${name} must be a positive number.`)
+    }
+  }
+
+  /**
+   * Calculates the perimeter of the rectangle.
+   * @public
+   * @returns {number} The perimeter of the rectangle.
+   */
+  perimeter() {
+    return 2 * (this.#length + this.#breadth)
+  }
+
+  /**
+   * Calculates the area of the rectangle.
+   * @public
+   * @returns {number} The area of the rectangle.
+   */
+  area() {
+    return this.#length * this.#breadth
+  }
+
+  /**
+   * Gets the length of the rectangle.
+   * @public
+   * @returns {number} The length of the rectangle.
+   */
+  get length() {
+    return this.#length
+  }
+
+  /**
+   * Gets the breadth of the rectangle.
+   * @public
+   * @returns {number} The breadth of the rectangle.
+   */
+  get breadth() {
+    return this.#breadth
+  }
+
+  /**
+   * Returns a string representation of the rectangle.
+   * @public
+   * @returns {string} A string describing the rectangle.
+   */
+  toString() {
+    return `Rectangle: length = ${this.#length}, breadth = ${
+      this.#breadth
+    }, area = ${this.area()}, perimeter = ${this.perimeter()}`
+  }
+}

Geometry/Test/Rectangle.test.js

@@ -0,0 +1,81 @@
+import Rectangle from '../Rectangle'
+
+describe('Rectangle', () => {
+  describe('Constructor', () => {
+    test('creates a rectangle with valid dimensions', () => {
+      const rectangle = new Rectangle(5, 3)
+      expect(rectangle).toBeInstanceOf(Rectangle)
+      expect(rectangle.length).toBe(5)
+      expect(rectangle.breadth).toBe(3)
+    })
+
+    test('throws an error if length is not a positive number', () => {
+      expect(() => new Rectangle(-1, 3)).toThrow(
+        'length must be a positive number.'
+      )
+      expect(() => new Rectangle(0, 3)).toThrow(
+        'length must be a positive number.'
+      )
+      expect(() => new Rectangle('5', 3)).toThrow(
+        'length must be a positive number.'
+      )
+    })
+
+    test('throws an error if breadth is not a positive number', () => {
+      expect(() => new Rectangle(5, -1)).toThrow(
+        'breadth must be a positive number.'
+      )
+      expect(() => new Rectangle(5, 0)).toThrow(
+        'breadth must be a positive number.'
+      )
+      expect(() => new Rectangle(5, '3')).toThrow(
+        'breadth must be a positive number.'
+      )
+    })
+  })
+
+  describe('Perimeter Calculation', () => {
+    test('calculates perimeter correctly', () => {
+      const rectangle = new Rectangle(5, 3)
+      expect(rectangle.perimeter()).toBe(16)
+    })
+
+    test('calculates perimeter correctly for a square', () => {
+      const square = new Rectangle(4, 4)
+      expect(square.perimeter()).toBe(16)
+    })
+  })
+
+  describe('Area Calculation', () => {
+    test('calculates area correctly', () => {
+      const rectangle = new Rectangle(5, 3)
+      expect(rectangle.area()).toBe(15)
+    })
+
+    test('calculates area correctly for a square', () => {
+      const square = new Rectangle(4, 4)
+      expect(square.area()).toBe(16)
+    })
+  })
+
+  describe('Getters', () => {
+    test('length getter returns correct value', () => {
+      const rectangle = new Rectangle(5, 3)
+      expect(rectangle.length).toBe(5)
+    })
+
+    test('breadth getter returns correct value', () => {
+      const rectangle = new Rectangle(5, 3)
+      expect(rectangle.breadth).toBe(3)
+    })
+  })
+
+  describe('toString Method', () => {
+    test('returns correct string representation', () => {
+      const rectangle = new Rectangle(5, 3)
+      expect(rectangle.toString()).toBe(
+        'Rectangle: length = 5, breadth = 3, area = 15, perimeter = 16'
+      )
+    })
+  })
+})