median.test.js

// median.test.js

// Someone has implemented calculateMedian but it isn't
// passing all the tests...
// Fix the implementation of calculateMedian so it passes all tests

const calculateMedian = require("./median.js");


  [
    { input: [1, 2, 3], expected: 2 },
    { input: [1, 2, 3, 4, 5], expected: 3 },
    { input: [1, 2, 3, 4], expected: 2.5 },
    { input: [1, 2, 3, 4, 5, 6], expected: 3.5 },
  ].forEach(({ input, expected }) =>
    it(`returns the median for [${input}]`, () => expect(calculateMedian(input)).toEqual(expected))
  );

  [
    { input: [3, 1, 2], expected: 2 },
    { input: [5, 1, 3, 4, 2], expected: 3 },
    { input: [4, 2, 1, 3], expected: 2.5 },
    { input: [6, 1, 5, 3, 2, 4], expected: 3.5 },
    { input: [110, 20, 0], expected: 20 },
    { input: [6, -2, 2, 12, 14], expected: 6 },
  ].forEach(({ input, expected }) =>
    it(`returns the correct median for unsorted array [${input}]`, () => expect(calculateMedian(input)).toEqual(expected))
  );

  it("doesn't modify the input array [3, 1, 2]", () => {
    const list = [3, 1, 2];
    calculateMedian(list);
    expect(list).toEqual([3, 1, 2]);
  });

  [ 'not an array', 123, null, undefined, {}, [], ["apple", null, undefined] ].forEach(val =>
    it(`returns null for non-numeric array (${val})`, () => expect(calculateMedian(val)).toBe(null))
  );

  [
    { input: [1, 2, "3", null, undefined, 4], expected: 2 },
    { input: ["apple", 1, 2, 3, "banana", 4], expected: 2.5 },
    { input: [1, "2", 3, "4", 5], expected: 3 },
    { input: [1, "apple", 2, null, 3, undefined, 4], expected: 2.5 },
    { input: [3, "apple", 1, null, 2, undefined, 4], expected: 2.5 },
    { input: ["banana", 5, 3, "apple", 1, 4, 2], expected: 3 },
  ].forEach(({ input, expected }) =>
    it(`filters out non-numeric values and calculates the median for [${input}]`, () => expect(calculateMedian(input)).toEqual(expected))
  );