London | 25-ITP-May | Houssam Lahlah | Sprint 1 | Sprint-1

Sprint-1/fix/median.js

@@ -1,14 +1,23 @@
-// Fix this implementation
-// Start by running the tests for this function
-// If you're in the Sprint-1 directory, you can run `npm test -- fix` to run the tests in the fix directory
+function calculateMedian(list) {
+  if (!Array.isArray(list) || list.length === 0) return null;
 
-// 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).
+  // Filter out non-number values
+  const numbers = list.filter(item => typeof item === "number");
+  if (numbers.length === 0) return null;
 
-function calculateMedian(list) {
-  const middleIndex = Math.floor(list.length / 2);
-  const median = list.splice(middleIndex, 1)[0];
-  return median;
+  // Sort numbers in ascending order
+  numbers.sort((a, b) => a - b);
+
+  const middleIndex = Math.floor(numbers.length / 2);
+
+  // If odd number of elements, return middle
+  if (numbers.length % 2 !== 0) {
+    return numbers[middleIndex];
+  }
+
+  // If even, return average of two middle numbers
+  return (numbers[middleIndex - 1] + numbers[middleIndex]) / 2;
 }
 
 module.exports = calculateMedian;
+

Sprint-1/fix/package.json

@@ -0,0 +1,8 @@
+{
+  "devDependencies": {
+    "jest": "^30.1.3"
+  },
+  "scripts": {
+    "test": "jest"
+  }
+}

Sprint-1/implement/dedupe.js

@@ -1 +1,18 @@
-function dedupe() {}
+function dedupe(arr) {
+  if (!Array.isArray(arr)) return [];
+
+  const seen = new Set();
+  const result = [];
+
+  for (const item of arr) {
+    if (!seen.has(item)) {
+      seen.add(item);
+      result.push(item);
+    }
+  }
+
+  return result;
+}
+
+module.exports = dedupe;
+

Sprint-1/implement/dedupe.test.js

@@ -1,27 +1,31 @@
 const dedupe = require("./dedupe.js");
-/*
-Dedupe Array
+describe("dedupe function", () => {
 
-📖 Dedupe means **deduplicate**
+  // Test 1: empty array
+  test("given an empty array, it returns an empty array", () => {
+    expect(dedupe([])).toEqual([]);
+  });
 
-In this kata, you will need to deduplicate the elements of an array
+  // Test 2: array with no duplicates
+  test("given an array with no duplicates, it returns a copy of the original array", () => {
+    const arr = [1, 2, 3, 4];
+    expect(dedupe(arr)).toEqual(arr);
+    expect(dedupe(arr)).not.toBe(arr); // ensure it returns a new array, not the same reference
+  });
 
-E.g. dedupe(['a','a','a','b','b','c']) target output: ['a','b','c']
-E.g. dedupe([5, 1, 1, 2, 3, 2, 5, 8]) target output: [5, 1, 2, 3, 8]
-E.g. dedupe([1, 2, 1]) target output: [1, 2]
-*/
+  // Test 3: array with duplicates (strings)
+  test("removes duplicate strings, preserving first occurrence", () => {
+    expect(dedupe(['a', 'a', 'a', 'b', 'b', 'c'])).toEqual(['a', 'b', 'c']);
+  });
 
-// Acceptance Criteria:
+  // Test 4: array with duplicates (numbers)
+  test("removes duplicate numbers, preserving first occurrence", () => {
+    expect(dedupe([5, 1, 1, 2, 3, 2, 5, 8])).toEqual([5, 1, 2, 3, 8]);
+  });
 
-// 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 5: mixed array
+  test("removes duplicates in mixed arrays", () => {
+    expect(dedupe([1, 2, 1])).toEqual([1, 2]);
+  });
 
-// Given an array with no duplicates
-// When passed to the dedupe function
-// Then it should return a copy of the original array
-
-// Given an array with strings or numbers
-// When passed to the dedupe function
-// Then it should remove the duplicate values, preserving the first occurence of each element
+});

Sprint-1/implement/max.js

@@ -1,4 +1,16 @@
-function findMax(elements) {
+function findMax(arr) {
+  if (!Array.isArray(arr) || arr.length === 0) return -Infinity;
+
+  let max = -Infinity;
+
+  for (const item of arr) {
+    if (typeof item === "number" && item > max) {
+      max = item;
+    }
+  }
+
+  return max;
 }
 
 module.exports = findMax;
+

Sprint-1/implement/max.test.js

@@ -1,43 +1,40 @@
-/* Find the maximum element of an array of numbers
-
-In this kata, you will need to implement a function that find the largest numerical element of an array.
-
-E.g. max([30, 50, 10, 40]), target output: 50
-E.g. max(['hey', 10, 'hi', 60, 10]), target output: 60 (sum ignores any non-numerical elements)
-
-You should implement this function in max.js, and add tests for it in this file.
+const findMax = require("./max.js");
 
-We have set things up already so that this file can see your function from the other file.
-*/
+describe("findMax function", () => {
 
-const findMax = require("./max.js");
+  // Test 1: empty array
+  test("given an empty array, returns -Infinity", () => {
+    expect(findMax([])).toBe(-Infinity);
+  });
 
-// Given an empty array
-// When passed to the max function
-// Then it should return -Infinity
-// Delete this test.todo and replace it with a test.
-test.todo("given an empty array, returns -Infinity");
+  // Test 2: array with one number
+  test("given an array with one number, returns that number", () => {
+    expect(findMax([42])).toBe(42);
+  });
 
-// Given an array with one number
-// When passed to the max function
-// Then it should return that number
+  // Test 3: array with positive and negative numbers
+  test("returns the largest number from mixed positive and negative numbers", () => {
+    expect(findMax([3, -2, 7, -10, 5])).toBe(7);
+  });
 
-// Given an array with both positive and negative numbers
-// When passed to the max function
-// Then it should return the largest number overall
+  // Test 4: array with only negative numbers
+  test("returns the closest number to zero for negative numbers", () => {
+    expect(findMax([-10, -2, -30])).toBe(-2);
+  });
 
-// Given an array with just negative numbers
-// When passed to the max function
-// Then it should return the closest one to zero
+  // Test 5: array with decimal numbers
+  test("returns the largest decimal number", () => {
+    expect(findMax([1.1, 2.5, 2.49])).toBe(2.5);
+  });
 
-// Given an array with decimal numbers
-// When passed to the max function
-// Then it should return the largest decimal number
+  // Test 6: array with non-number values
+  test("ignores non-numeric values and returns the largest number", () => {
+    expect(findMax([10, "apple", 20, null, 5])).toBe(20);
+  });
 
-// Given an array with non-number values
-// When passed to the max function
-// Then it should return the max and ignore non-numeric values
+  // Test 7: array with only non-number values
+  test("array with only non-number values returns -Infinity", () => {
+    expect(findMax(["a", null, "b"])).toBe(-Infinity);
+  });
 
-// Given an array with only non-number values
-// When passed to the max function
-// Then it should return the least surprising value given how it behaves for all other inputs
+});

Sprint-1/implement/package.json

@@ -0,0 +1,8 @@
+{
+  "devDependencies": {
+    "jest": "^30.1.3"
+  },
+  "scripts": {
+    "test": "jest"
+  }
+}

Sprint-1/implement/sum.js

@@ -1,4 +1,10 @@
-function sum(elements) {
+function sum(arr) {
+  if (!Array.isArray(arr)) return 0;
+
+  return arr.reduce((total, item) => {
+    return typeof item === "number" ? total + item : total;
+  }, 0);
 }
 
 module.exports = sum;
+

Sprint-1/implement/sum.test.js

@@ -1,36 +1,35 @@
-/* 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:
+describe("sum function", () => {
+
+  // Test 1: empty array
+  test("given an empty array, returns 0", () => {
+    expect(sum([])).toBe(0);
+  });
 
-// Given an empty array
-// When passed to the sum function
-// Then it should return 0
-test.todo("given an empty array, returns 0")
+  // Test 2: array with one number
+  test("given an array with one number, returns that number", () => {
+    expect(sum([42])).toBe(42);
+  });
 
-// Given an array with just one number
-// When passed to the sum function
-// Then it should return that number
+  // Test 3: array with positive and negative numbers
+  test("returns the correct total sum for positive and negative numbers", () => {
+    expect(sum([10, -5, 15, -3])).toBe(17);
+  });
 
-// Given an array containing negative numbers
-// When passed to the sum function
-// Then it should still return the correct total sum
+  // Test 4: array with decimal numbers
+  test("returns the correct total sum for decimal/float numbers", () => {
+    expect(sum([1.5, 2.3, 3.2])).toBeCloseTo(7.0); // Use toBeCloseTo for floating points
+  });
 
-// Given an array with decimal/float numbers
-// When passed to the sum function
-// Then it should return the correct total sum
+  // Test 5: array with non-number values
+  test("ignores non-numeric values and sums numerical elements", () => {
+    expect(sum([10, "a", 20, null, 5])).toBe(35);
+  });
 
-// 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 6: array with only non-number values
+  test("returns 0 if there are no numeric elements", () => {
+    expect(sum(["a", null, "b"])).toBe(0);
+  });
 
-// 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
+});

Sprint-1/refactor/includes.js

@@ -1,8 +1,6 @@
-// Refactor the implementation of includes to use a for...of loop
-
+// Check if a list includes a target value
 function includes(list, target) {
-  for (let index = 0; index < list.length; index++) {
-    const element = list[index];
+  for (const element of list) {
     if (element === target) {
       return true;
     }
@@ -11,3 +9,4 @@ function includes(list, target) {
 }
 
 module.exports = includes;
+

Sprint-1/refactor/package.json

@@ -0,0 +1,8 @@
+{
+  "devDependencies": {
+    "jest": "^30.1.3"
+  },
+  "scripts": {
+    "test": "jest"
+  }
+}