Math:Fibonacci Added

src/algorithms/math/fibonacci.js

@@ -0,0 +1,25 @@
+/**
+ * Show fibonacci sequence up to a given number
+ * @param {Number} num given number
+ */
+const fibonacci = (num) => {
+  let n1 = 0;
+  let n2 = 1;
+  const fibo = [];
+
+  if (num < 0) {
+    throw new Error('Not a positive number');
+  }
+
+  while (n1 <= num) {
+    fibo.push(n1);
+
+    const sum = n1 + n2;
+    n1 = n2;
+    n2 = sum;
+  }
+
+  return fibo;
+};
+
+module.exports = fibonacci;

src/algorithms/math/index.js

@@ -3,11 +3,13 @@ const gcd = require('./gcd');
 const fastexp = require('./fast_exp');
 const lcm = require('./lcm');
 const modularInverse = require('./modular_inverse');
+const fibonacci = require('./fibonacci');
 
 module.exports = {
   extendedEuclidean,
   gcd,
   fastexp,
   lcm,
-  modularInverse
+  modularInverse,
+  fibonacci
 };

test/algorithms/math/testFibonacci.js

@@ -0,0 +1,22 @@
+/* eslint-env mocha */
+const fibonacci = require('../../../src/algorithms/math/fibonacci');
+
+const assert = require('assert');
+
+describe('Fibonacci', () => {
+  it('should return 0 if given number is 0', () => {
+    assert.deepStrictEqual(fibonacci(0), [0]);
+  });
+
+  it('should throw an error if the number is negative', () => {
+    assert.throws(() => fibonacci(-5));
+  });
+
+  it('should return fibonacci sequence up to 10', () => {
+    assert.deepStrictEqual(fibonacci(10), [0, 1, 1, 2, 3, 5, 8]);
+  });
+
+  it('should return fibonacci sequence up to 100', () => {
+    assert.deepStrictEqual(fibonacci(100), [0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89]);
+  });
+});