sum.test.js

/* Sum the numbers in an array

In this kata, you will need to implement a function that sums the numerical elements of an array

E.g. sum([10, 20, 30]), target output: 60
E.g. sum(['hey', 10, 'hi', 60, 10]), target output: 80 (ignore any non-numerical elements)
*/

const sum = require("./sum.js");

// Acceptance Criteria:

// Given an empty array
// When passed to the sum function
// Then it should return 0

// Given an array with just one number
// When passed to the sum function
// Then it should return that number

// Given an array containing negative numbers
// When passed to the sum function
// Then it should still return the correct total sum

// Given an array with decimal/float numbers
// When passed to the sum function
// Then it should return the correct total sum

// 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

// 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

describe("sum", () => {
  [
    { input: ["apple", "banana", 1, 10], expected: 11 },
    { input: [1, -1, -100], expected: -100 },
    { input: [-10, -20, -3, -4], expected: -37 },
    { input: [1.5, 10.5, 0.5], expected: 12.5 },
    { input: ["apple", "banana", "cherry"], expected: -Infinity },
  ].forEach(({ input, expected }) =>
    it(`returns the sum for [${input}]`, () =>
      expect(sum(input)).toEqual(expected))
  );
});