Glasgow | 25-ITP-SEP | Alaa Tagi | Sprint 1| Coursework/sprint 1

Sprint-1/fix/median.js

@@ -5,9 +5,33 @@
 // 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) {
-  const middleIndex = Math.floor(list.length / 2);
-  const median = list.splice(middleIndex, 1)[0];
+  if (!Array.isArray(list)) {
+
+    return null;
+  } 
+  // Filter out non-numeric values
+  const filteredList = list.filter(item => typeof item === 'number' && !isNaN(item));
+
+  // If there are no valid numbers, return null
+  if (filteredList.length === 0) {
+    return null;
+  }
+
+  // Sort numerically (without modifying the original array)
+  const sortedList = filteredList.slice().sort((a, b) => a - b);
+
+  // Compute the median
+  const midIndex = Math.floor(sortedList.length / 2);
+  let median;
+
+  if (sortedList.length % 2 === 0) {
+    median = (sortedList[midIndex - 1] + sortedList[midIndex]) / 2;
+  } else {
+    median = sortedList[midIndex];
+  }
+
   return median;
 }
 

Sprint-1/implement/dedupe.js

@@ -1 +1,6 @@
-function dedupe() {}
+function dedupe(arr) {
+    const deduplicatedArray = arr.filter((item, index) => arr.indexOf(item) === index);
+    return deduplicatedArray;
+}
+
+module.exports = dedupe;

Sprint-1/implement/dedupe.test.js

@@ -16,12 +16,38 @@ E.g. dedupe([1, 2, 1]) target output: [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, it returns an empty array", () => {
+    [
+        {input:[], expected:[]}
+    ].forEach(({input, expected}) => {
+        const result = dedupe(input);
+        expect(result).toEqual(expected);
+    });
+});
 
 // Given an array with no duplicates
 // When passed to the dedupe function
 // Then it should return a copy of the original array
+test("given an array with no duplicates, it returns a copy of the original array", () => {
+    [
+        {input:[1, 2, 3], expected:[1, 2, 3]},
+        {input:['a', 'b', 'c'], expected:['a', 'b', 'c']}
+    ].forEach(({input, expected}) => {
+        const result = dedupe(input);
+        expect(result).toEqual(expected);
+    });
+});
 
 // 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
+test("given an array with strings or numbers, it removes duplicate values preserving the first occurrence of each element", () => {
+    [
+        {input:['a','a','a','b','b','c'], expected:['a','b','c']},
+        {input:[5, 1, 1, 2, 3, 2, 5, 8], expected:[5, 1, 2, 3, 8]},
+        {input:[1, 2, 1], expected:[1, 2]}
+    ].forEach(({input, expected}) => {
+        const result = dedupe(input);
+        expect(result).toEqual(expected);
+    });
+});

Sprint-1/implement/max.js

@@ -1,4 +1,11 @@
 function findMax(elements) {
+    let max = -Infinity;
+    for (let i = 0; i < elements.length; i++) {
+        if (elements[i] > max) {
+            max = elements[i];
+        }
+    }
+    return max; 
 }
 
 module.exports = findMax;

Sprint-1/implement/max.test.js

@@ -16,28 +16,54 @@ const findMax = require("./max.js");
 // 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("given an empty array, returns -Infinity", () => {
+    expect(findMax([])).toBe(-Infinity);
+});
 
 // Given an array with one number
 // When passed to the max function
 // Then it should return that number
+
+test("given an array with one number, returns that number", () => {
+    expect(findMax([33])).toBe(33);
+});
 
 // Given an array with both positive and negative numbers
 // When passed to the max function
 // Then it should return the largest number overall
 
+test("given an array with both positive and negative numbers, returns the largest number overall", () => {
+    expect(findMax([-10, -20, 0, 10, 20])).toBe(20);
+});
+
 // Given an array with just negative numbers
 // When passed to the max function
 // Then it should return the closest one to zero
 
+test("given an array with just negative numbers, returns the closest one to zero", () => {
+    expect(findMax([-10, -20, -30])).toBe(-10);
+});
+
 // Given an array with decimal numbers
 // When passed to the max function
 // Then it should return the largest decimal number
 
+test("given an array with decimal numbers, returns the largest decimal number", () => {
+    expect(findMax([1.5, 2.5, 3.5, 2.9])).toBe(3.5);
+});
+
 // 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("given an array with non-number values, returns the max and ignores non-numeric values", () => {
+    expect(findMax(['hey', 10, 'hi', 60, 10])).toBe(60);
+});
+
 // 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
+
+test("given an array with only non-number values, returns -Infinity", () => {
+    expect(findMax(['hey', 'hi', 'hello'])).toBe(-Infinity);
+});

Sprint-1/implement/sum.js

@@ -1,4 +1,11 @@
 function sum(elements) {
+    let total = 0;
+    for (let i = 0; i < elements.length; i++) {
+        if (typeof elements[i] === "number") {
+            total += elements[i];
+        }
+    }
+    return total;
 }
 
 module.exports = sum;

Sprint-1/implement/sum.test.js

@@ -13,24 +13,46 @@ const sum = require("./sum.js");
 // Given an empty array
 // When passed to the sum function
 // Then it should return 0
-test.todo("given an empty array, returns 0")
+test("given an empty array, returns 0", () => {
+    expect(sum([])).toBe(0);
+});
 
 // Given an array with just one number
 // When passed to the sum function
 // Then it should return that number
 
+test("given an array with just one number, returns that number", () => {
+    expect(sum([40])).toBe(40);
+});
+
 // Given an array containing negative numbers
 // When passed to the sum function
 // Then it should still return the correct total sum
 
+test("given an array containing negative numbers, returns the correct total sum", () => {
+    expect(sum([-10, -20, -30])).toBe(-60);
+});
+
 // Given an array with decimal/float numbers
 // When passed to the sum function
 // Then it should return the correct total sum
 
+test("given an array with decimal numbers, returns the correct total sum", () => {
+    expect(sum([1.5, 2.5, 3.5])).toBe(7.5);
+});
+
 // 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("given an array containing non-number values, returns the correct total sum", () => {
+    expect(sum(['hey', 10, 'hi', 60, 10])).toBe(80);
+});
+
 // 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
+
+test("given an array with only non-number values, returns 0", () => {
+    expect(sum(['hey', 'hi', 'hello'])).toBe(0);
+});

Sprint-1/refactor/includes.js

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