Implemented the dedupe function and all tests pass.

Author: d-odumosu

Sprint-1/fix/median.js

@@ -5,29 +5,28 @@
 // Hint: Please consider scenarios when 'list' doesn't have numbers (the function is expected to return null)
 // or 'list' has mixed values (the function is expected to sort only numbers).
 
-
 function calculateMedian(list) {
-    if (!Array.isArray(list)) {
-        return null
-    }
-    const arrCopy = [...list]
-    const filteredNumbers = arrCopy.filter((num => Number.isFinite(num)));
+  if (!Array.isArray(list)) {
+    return null;
+  }
+  const arrCopy = [...list];
+  const filteredNumbers = arrCopy.filter((num) => Number.isFinite(num));
 
-    if (filteredNumbers.length === 0) {
-        return null
-    }
+  if (filteredNumbers.length === 0) {
+    return null;
+  }
 
-    const sortedNumbers = filteredNumbers.sort((a, b) => a - b);
-    let middleIndex
-    if (sortedNumbers.length % 2 === 0) {
-        middleIndex = sortedNumbers.length / 2
-        const firstMiddleIndex = sortedNumbers[middleIndex - 1];
-        const secondMiddleIndex = sortedNumbers[middleIndex];
-        return (firstMiddleIndex + secondMiddleIndex) / 2
-    } else {
-        middleIndex = Math.floor(sortedNumbers.length / 2);
-        return sortedNumbers[middleIndex];
-    }
+  const sortedNumbers = filteredNumbers.sort((a, b) => a - b);
+  let middleIndex;
+  if (sortedNumbers.length % 2 === 0) {
+    middleIndex = sortedNumbers.length / 2;
+    const firstMiddleIndex = sortedNumbers[middleIndex - 1];
+    const secondMiddleIndex = sortedNumbers[middleIndex];
+    return (firstMiddleIndex + secondMiddleIndex) / 2;
+  } else {
+    middleIndex = Math.floor(sortedNumbers.length / 2);
+    return sortedNumbers[middleIndex];
+  }
 }
 
 // console.log(calculateMedian([100, 2, 3, 'f', 4, 9, 9, 0, "hey", 'g']))

Sprint-1/fix/median.test.js

@@ -13,7 +13,8 @@ describe("calculateMedian", () => {
     { 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 [${input}]`, () => expect(calculateMedian(input)).toEqual(expected))
+    it(`returns the median for [${input}]`, () =>
+      expect(calculateMedian(input)).toEqual(expected))
   );
 
   [
@@ -24,7 +25,8 @@ describe("calculateMedian", () => {
     { 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 [${input}]`, () => expect(calculateMedian(input)).toEqual(expected))
+    it(`returns the correct median for unsorted array [${input}]`, () =>
+      expect(calculateMedian(input)).toEqual(expected))
   );
 
   it("doesn't modify the input array [3, 1, 2]", () => {
@@ -33,8 +35,17 @@ describe("calculateMedian", () => {
     expect(list).toEqual([3, 1, 2]);
   });
 
-  [ 'not an array', 123, null, undefined, {}, [], ["apple", null, undefined] ].forEach(val =>
-    it(`returns null for non-numeric array (${val})`, () => expect(calculateMedian(val)).toBe(null))
+  [
+    "not an array",
+    123,
+    null,
+    undefined,
+    {},
+    [],
+    ["apple", null, undefined],
+  ].forEach((val) =>
+    it(`returns null for non-numeric array (${val})`, () =>
+      expect(calculateMedian(val)).toBe(null))
   );
 
   [
@@ -45,6 +56,7 @@ describe("calculateMedian", () => {
     { 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 [${input}]`, () => expect(calculateMedian(input)).toEqual(expected))
+    it(`filters out non-numeric values and calculates the median for [${input}]`, () =>
+      expect(calculateMedian(input)).toEqual(expected))
   );
 });

Sprint-1/implement/dedupe.js

@@ -1 +1,9 @@
-function dedupe() {}
+function dedupe(elements) {
+  if (elements.length === 0) {
+    return [];
+  }
+
+  return elements.filter((item, index) => elements.indexOf(item) === index);
+}
+
+module.exports = dedupe;

Sprint-1/implement/dedupe.test.js

@@ -16,13 +16,46 @@ E.g. dedupe([1, 2, 1]) returns [1, 2]
 // Given an empty array
 // When passed to the dedupe function
 // Then it should return an empty array
-test.todo("given an empty array, it returns an empty array");
+test("given an empty array, return an empty array", () => {
+  expect(dedupe([])).toEqual([]);
+});
 
 // Given an array with no duplicates
 // When passed to the dedupe function
 // Then it should return a copy of the original array
+const testCaseNoDuplicates = [
+  {
+    input: ["hey", "buddy", "world", "10", "sister", 1],
+    expected: ["hey", "buddy", "world", "10", "sister", 1],
+  },
+  {
+    input: [2, 3, 4, 5, 6, 7],
+    expected: [2, 3, 4, 5, 6, 7],
+  },
+];
+testCaseNoDuplicates.forEach(({ input, expected }) => {
+  test("given an array with no duplicates, return a copy of the array", () => {
+    expect(dedupe(input)).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 
+// Then it should return a new array with duplicates removed while preserving the
 // first occurrence of each element from the original array.
+const testCaseWithDuplicates = [
+  { input: [1, 2, 2, 3, 1], expected: [1, 2, 3] },
+  { input: ["a", "b", "a", "c", "b"], expected: ["a", "b", "c"] },
+  { input: [5, 5, 1, 1, 2, 3, 2], expected: [5, 1, 2, 3] },
+  {
+    input: ["apple", "banana", "apple", "orange"],
+    expected: ["apple", "banana", "orange"],
+  },
+  { input: [1, "a", 1, "b", "a", 2], expected: [1, "a", "b", 2] },
+  { input: ["hey", "hey", "hey", "hey", "hey", "hey"], expected: ["hey"] },
+];
+testCaseWithDuplicates.forEach(({ input, expected }) => {
+  test("given an array with duplicates, return a new array with only the first occurrence", () => {
+    expect(dedupe(input)).toEqual(expected);
+  });
+});

Sprint-1/package-lock.json

@@ -10,6 +10,7 @@
   "author": "",
   "license": "ISC",
   "devDependencies": {
-    "jest": "^29.7.0"
+    "jest": "^29.7.0",
+    "prettier": "3.9.6"
   }
 }