dedupe.test.js

const dedupe = require("./dedupe.js");
const findMax = require("./max.js");
/*
Dedupe Array

📖 Dedupe means **deduplicate**

In this kata, you will need to deduplicate the elements of an array

E.g. dedupe(['a','a','a','b','b','c']) returns ['a','b','c']
E.g. dedupe([5, 1, 1, 2, 3, 2, 5, 8]) returns [5, 1, 2, 3, 8]
E.g. dedupe([1, 2, 1]) returns [1, 2]
*/

// Acceptance Criteria:

// Given an empty array
// When passed to the dedupe function
// Then it should return an empty array
test("with input of empty array should return, empty array", () => {
  let emptyArray = [];
  expect(dedupe(emptyArray)).toEqual([]);
});

// Given an array with no duplicates
// When passed to the dedupe function
// Then it should return a copy of the original array
test("with input of array with no duplicates should return a copy of original array", () => {
  const normalArray = [1, 2, 3, 4, 5, 6, 10];
  const expected = [1, 2, 3, 4, 5, 6, 10]; // separate copy

  const result = dedupe(normalArray);

  // 1. Correct values
  expect(result).toEqual(expected);

  // 2. Different array in memory
  expect(result).not.toBe(normalArray);

  // 3. Original array not mutated
  expect(normalArray).toEqual(expected);
}
);

// Given an array of strings or numbers
// When passed to the dedupe function
// Then it should return a new array with duplicates removed while preserving the
// first occurrence of each element from the original array.
test("with input of empty array should return, empty array", () => {
  let mixValueArray = [1, 1, 1, 2, 2, "Hello", "Hello", "Hello", 3, 4, 4, 5];
  expect(dedupe(mixValueArray)).toEqual([1, 2, "Hello", 3, 4, 5]);
});