feat: added function to check co-prime

maths/check_co_prime.ts

@@ -0,0 +1,29 @@
+import { greatestCommonFactor } from './greatest_common_factor'
+
+/**
+ * @function areCoPrime
+ * @description Check if two numbers are co-prime
+ * @param {number} a - first number
+ * @param {number} b - second number
+ * @returns {boolean} - true if a and b are co-prime, false otherwise
+ * @throws {TypeError} - if inputs are not integers
+ * @throws {Error} - if inputs are zero
+ * @see https://en.wikipedia.org/wiki/Coprime_integers
+ * @example areCoPrime(14, 15) => true
+ *
+ */
+
+export const areCoPrime = (a: number, b: number): boolean => {
+  if (!Number.isInteger(a) || !Number.isInteger(b)) {
+    throw new TypeError('Inputs must be integers')
+  }
+
+  if (a === 0 || b === 0) {
+    throw new Error('Inputs must be non-zero')
+  }
+
+  a = Math.abs(a)
+  b = Math.abs(b)
+
+  return greatestCommonFactor([a, b]) === 1
+}

maths/test/check_co_prime.test.ts

@@ -0,0 +1,23 @@
+import { areCoPrime } from '../check_co_prime'
+
+describe('Check if two numbers are co-prime', () => {
+  test('should return true if two numbers are co-prime', () => {
+    expect(areCoPrime(14, 15)).toBeTruthy()
+    expect(areCoPrime(8, 9)).toBeTruthy()
+    expect(areCoPrime(3, -5)).toBeTruthy()
+  })
+
+  test('should return false if two numbers are not co-prime', () => {
+    expect(areCoPrime(14, 21)).toBeFalsy()
+    expect(areCoPrime(8, 12)).toBeFalsy()
+    expect(areCoPrime(3, 6)).toBeFalsy()
+  })
+
+  test('should throw a TypeError if inputs are not integers', () => {
+    expect(() => areCoPrime(14.5, 15)).toThrow(TypeError)
+  })
+
+  test('should throw an Error if inputs are zero', () => {
+    expect(() => areCoPrime(0, 15)).toThrow(Error)
+  })
+})