03_fibonacci: Update exercise to return "OOPS" for 0

foundations/object_basics/03_fibonacci/README.md

@@ -1,6 +1,6 @@
 # Exercise 03 - Fibonacci
 
-Create a function that returns a specific member of the Fibonacci sequence (series of numbers in which each number is the sum of the two preceding numbers). To learn more about Fibonacci sequences, go to: https://en.wikipedia.org/wiki/Fibonacci_sequence
+Create a function that returns a specific member of the Fibonacci sequence (series of numbers in which each number is the sum of the two preceding numbers). To learn more about Fibonacci sequences, go to: <https://en.wikipedia.org/wiki/Fibonacci_sequence>
 
 In this exercise, the Fibonacci sequence used is 1, 1, 2, 3, 5, 8, etc. (i.e. starting at 1, not 0):
 
@@ -9,4 +9,4 @@ fibonacci(4); // returns the 4th member of the series: 3  (1, 1, 2, 3)
 fibonacci(6); // returns 8
 ```
 
-If given a negative number, `NaN`, or not a number type at all, the function should return `"OOPS"`, i.e. only proceed with positive numbers.
+If given 0, a negative number, `NaN`, or not a number type at all, the function should return `"OOPS"`, i.e. only proceed with positive numbers.

foundations/object_basics/03_fibonacci/fibonacci.spec.js

@@ -16,8 +16,8 @@ describe('fibonacci', () => {
   test.skip('25th fibonacci number is 75025', () => {
     expect(fibonacci(25)).toBe(75025);
   });
-  test.skip('0th fibonacci number is 0', () => {
-    expect(fibonacci(0)).toBe(0);
+  test.skip('doesn\'t accept 0', () => {
+    expect(fibonacci(0)).toBe("OOPS");
   });
   test.skip('doesn\'t accept negatives', () => {
     expect(fibonacci(-25)).toBe("OOPS");

foundations/object_basics/03_fibonacci/solution/fibonacci-solution.js

@@ -1,13 +1,9 @@
 const fibonacci = function(count) {
     // checks argument's type and makes sure we use
-    // a number throughout rest of function.
-    if (typeof count !== 'number' || count < 0 || Number.isNaN(count)) {
+    // a positive number throughout rest of function.
+    if (typeof count !== 'number' || count <= 0 || Number.isNaN(count)) {
         return "OOPS";
     }
-
-    if (count === 0) {
-        return 0;
-    }
 
     let firstPrev = 1;
     let secondPrev = 0;

foundations/object_basics/03_fibonacci/solution/fibonacci-solution.spec.js

@@ -16,8 +16,8 @@ describe('fibonacci', () => {
   test('25th fibonacci number is 75025', () => {
     expect(fibonacci(25)).toBe(75025);
   });
-  test('0th fibonacci number is 0', () => {
-    expect(fibonacci(0)).toBe(0);
+  test('doesn\'t accept 0', () => {
+    expect(fibonacci(0)).toBe("OOPS");
   });
   test('doesn\'t accept negatives', () => {
     expect(fibonacci(-25)).toBe("OOPS");