sumtest exercise completed.

Author: Dan2Clouted

Sprint-1/implement/sum.js

@@ -1,4 +1,12 @@
 function sum(elements) {
+  let total = 0;
+
+  for (let i = 0; i < elements.length; i++) {
+    if (typeof elements[i] === "number") {
+      total += elements[i];
+    }
+  }
+  return total;
 }
 
 module.exports = sum;

Sprint-1/implement/sum.test.js

@@ -13,24 +13,71 @@ const sum = require("./sum.js");
 // Given an empty array
 // When passed to the sum function
 // Then it should return 0
-test.todo("given an empty array, returns 0")
+test("given an empty array, returns 0", () => {
+  const input = [];
+  const expectedOutput = 0;
+  expect(sum(input)).toBe(expectedOutput);
+});
 
 // Given an array with just one number
 // When passed to the sum function
 // Then it should return that number
+test("given an array with just one number, returns that number", () => {
+  const input = [5];
+  const expectedOutput = 5;
+  expect(sum(input)).toBe(expectedOutput);
+});
 
 // Given an array containing negative numbers
 // When passed to the sum function
 // Then it should still return the correct total sum
+test("given an array containing negative numbers, it returns the correct total sum", () => {
+  const input = [10, -5, 20, -3];
+  const expectedOutput = 22;
+  expect(sum(input)).toBe(expectedOutput);
+});
 
 // Given an array with decimal/float numbers
 // When passed to the sum function
 // Then it should return the correct total sum
+test("given an array with decimal numbers, it returns the correct total sum", () => {
+  const input = [1.5, 2.3, 0.7];
+  const expectedOutput = 4.5;
+  expect(sum(input)).toBe(expectedOutput);
+});
+
+// Given an array with decimal/float numbers
+// When passed to the sum function
+// Then it should return the correct total sum
+test("given an array with decimal numbers, it returns the correct total sum", () => {
+  const input = [1.5, 2.3, 0.7];
+  const expectedOutput = 4.5;
+  expect(sum(input)).toBe(expectedOutput);
+});
+
+// Given an array containing non-number values
+// When passed to the sum function
+// Then it should ignore the non-numerical values and return the sum of the numerical elements
+test("given an array containing non-number values, it ignores them and returns the sum of the numerical elements", () => {
+  const input = [10, "hello", 20, null, 5];
+  const expectedOutput = 35;
+  expect(sum(input)).toBe(expectedOutput);
+});
 
 // Given an array containing non-number values
 // When passed to the sum function
 // Then it should ignore the non-numerical values and return the sum of the numerical elements
+test("given an array containing non-number values, it ignores them and returns the sum of the numerical elements", () => {
+  const input = ["hello", "world"];
+  const expectedOutput = 0;
+  expect(sum(input)).toBe(expectedOutput);
+});
 
 // Given an array with only non-number values
 // When passed to the sum function
 // Then it should return the least surprising value given how it behaves for all other inputs
+test("given an array with only non-number values, it returns the least surprising value", () => {
+  const input = ["hello", "world"];
+  const expectedOutput = 0;
+  expect(sum(input)).toBe(expectedOutput);
+});