From 54c6c538c30e44a577811f3dded79dd5adeda77c Mon Sep 17 00:00:00 2001 From: Ali Date: Mon, 17 Nov 2025 10:22:13 +0000 Subject: [PATCH 1/7] Refactor: improve median calculation to handle non-numeric values and sort correctly --- Sprint-1/fix/median.js | 23 ++++++++++++++++++++--- 1 file changed, 20 insertions(+), 3 deletions(-) diff --git a/Sprint-1/fix/median.js b/Sprint-1/fix/median.js index b22590bc6..aea8f3ce5 100644 --- a/Sprint-1/fix/median.js +++ b/Sprint-1/fix/median.js @@ -6,9 +6,26 @@ // 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]; - return median; + // Filter only number values + const numbers = list.filter((item) => typeof item === "number"); + + // Return null if no valid numbers found + if (numbers.length === 0) { + return null; + } + + // Sort numerically (not alphabetically) + numbers.sort((a, b) => a - b); + + const middleIndex = Math.floor(numbers.length / 2); + + // Odd number of elements → return the middle one + if (numbers.length % 2 !== 0) { + return numbers[middleIndex]; + } + + // Even number → average of the two middle values + return (numbers[middleIndex - 1] + numbers[middleIndex]) / 2; } module.exports = calculateMedian; From 9450fc0d646e2a9426cbf9c48d6da2a5444929ef Mon Sep 17 00:00:00 2001 From: Ali Date: Mon, 17 Nov 2025 10:44:14 +0000 Subject: [PATCH 2/7] Refactor: enhance median calculation to ensure input is an array and sort without modifying original data --- Sprint-1/fix/median.js | 25 +++++++++++++++---------- 1 file changed, 15 insertions(+), 10 deletions(-) diff --git a/Sprint-1/fix/median.js b/Sprint-1/fix/median.js index aea8f3ce5..26435293f 100644 --- a/Sprint-1/fix/median.js +++ b/Sprint-1/fix/median.js @@ -6,26 +6,31 @@ // or 'list' has mixed values (the function is expected to sort only numbers). function calculateMedian(list) { + + // First: ensure input is actually an array BEFORE calling array methods + if (!Array.isArray(list)) { + return null; + } + // Filter only number values const numbers = list.filter((item) => typeof item === "number"); - // Return null if no valid numbers found + // Return null if no valid numbers exist if (numbers.length === 0) { return null; } - // Sort numerically (not alphabetically) - numbers.sort((a, b) => a - b); - - const middleIndex = Math.floor(numbers.length / 2); + // Sort values without modifying original input + const sortedNumbers = [...numbers].sort((a, b) => a - b); + const middleIndex = Math.floor(sortedNumbers.length / 2); - // Odd number of elements → return the middle one - if (numbers.length % 2 !== 0) { - return numbers[middleIndex]; + // Odd length → return middle value + if (sortedNumbers.length % 2 !== 0) { + return sortedNumbers[middleIndex]; } - // Even number → average of the two middle values - return (numbers[middleIndex - 1] + numbers[middleIndex]) / 2; + // Even length → return average of two middle values + return (sortedNumbers[middleIndex - 1] + sortedNumbers[middleIndex]) / 2; } module.exports = calculateMedian; From f2b76fa732b5b48321d17b8c14b89ed4fc3f33e8 Mon Sep 17 00:00:00 2001 From: Ali Date: Tue, 18 Nov 2025 23:49:18 +0000 Subject: [PATCH 3/7] Implement dedupe function and add tests for various scenarios --- Sprint-1/implement/dedupe.js | 21 ++++++++++++++++++++- Sprint-1/implement/dedupe.test.js | 16 +++++++++++++++- 2 files changed, 35 insertions(+), 2 deletions(-) diff --git a/Sprint-1/implement/dedupe.js b/Sprint-1/implement/dedupe.js index 781e8718a..5f74993a0 100644 --- a/Sprint-1/implement/dedupe.js +++ b/Sprint-1/implement/dedupe.js @@ -1 +1,20 @@ -function dedupe() {} +function dedupe(arr) { + + if (!Array.isArray(arr)) return null; + + // Create a new result array + const result = []; + + // Loop through original array + for (const item of arr) { + // Add only the first occurrence of each element + if (!result.includes(item)) { + result.push(item); + } + } + + // Return the deduplicated array + return result; +} + +module.exports = dedupe; diff --git a/Sprint-1/implement/dedupe.test.js b/Sprint-1/implement/dedupe.test.js index 23e0f8638..2daa8447b 100644 --- a/Sprint-1/implement/dedupe.test.js +++ b/Sprint-1/implement/dedupe.test.js @@ -16,12 +16,26 @@ 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", () => { + 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 +test("given an array with no duplicates, returns a copy", () => { + const arr = [1, 2, 3]; + const result = dedupe(arr); + + expect(result).toEqual([1, 2, 3]); + expect(result).not.toBe(arr); // ensure it's a new array, not the same reference +}); // 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("removes duplicate values and preserves first occurrence", () => { + expect(dedupe(["a", "a", "a", "b", "b", "c"])).toEqual(["a", "b", "c"]); + expect(dedupe([5, 1, 1, 2, 3, 2, 5, 8])).toEqual([5, 1, 2, 3, 8]); + expect(dedupe([1, 2, 1])).toEqual([1, 2]); +}); From 42817a8c52986cb8504bfb62b94157024818295b Mon Sep 17 00:00:00 2001 From: Ali Date: Tue, 18 Nov 2025 23:52:09 +0000 Subject: [PATCH 4/7] Refactor: enhance findMax function and add comprehensive tests for various scenarios --- Sprint-1/implement/max.js | 11 +++++++++++ Sprint-1/implement/max.test.js | 22 +++++++++++++++++++++- 2 files changed, 32 insertions(+), 1 deletion(-) diff --git a/Sprint-1/implement/max.js b/Sprint-1/implement/max.js index 6dd76378e..2d82ee2f4 100644 --- a/Sprint-1/implement/max.js +++ b/Sprint-1/implement/max.js @@ -1,4 +1,15 @@ function findMax(elements) { + // If elements is not an array, return -Infinity (least surprising behaviour) + if (!Array.isArray(elements)) return -Infinity; + + // Filter numeric values only + const numbers = elements.filter((item) => typeof item === "number"); + + // If no numeric values found, return -Infinity + if (numbers.length === 0) return -Infinity; + + // Return the maximum number + return Math.max(...numbers); } module.exports = findMax; diff --git a/Sprint-1/implement/max.test.js b/Sprint-1/implement/max.test.js index 82f18fd88..3f2585667 100644 --- a/Sprint-1/implement/max.test.js +++ b/Sprint-1/implement/max.test.js @@ -16,28 +16,48 @@ 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([42])).toBe(42); +}); // 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 mixed positive and negative numbers, returns the largest", () => { + expect(findMax([-10, 5, 20, -3])).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 only negative numbers, returns the one closest to zero", () => { + expect(findMax([-50, -10, -3, -100])).toBe(-3); +}); // Given an array with decimal numbers // When passed to the max function // Then it should return the largest decimal number +test("given decimal numbers, returns the largest value", () => { + expect(findMax([1.5, 2.7, 2.6, 0.1])).toBe(2.7); +}); // 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("ignores non-numeric values and returns the maximum number", () => { + expect(findMax(["hi", 10, "wow", 30, 5])).toBe(30); +}); // 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 only non-number values, returns -Infinity", () => { + expect(findMax(["a", "b", {}, null])).toBe(-Infinity); +}); From 94095aa1266a0fca78584ef512bac6563a9526da Mon Sep 17 00:00:00 2001 From: Ali Date: Tue, 18 Nov 2025 23:54:22 +0000 Subject: [PATCH 5/7] Refactor: enhance sum function and add comprehensive tests for various scenarios --- Sprint-1/implement/sum.js | 7 +++++++ Sprint-1/implement/sum.test.js | 19 ++++++++++++++++++- 2 files changed, 25 insertions(+), 1 deletion(-) diff --git a/Sprint-1/implement/sum.js b/Sprint-1/implement/sum.js index 9062aafe3..4a8c2692d 100644 --- a/Sprint-1/implement/sum.js +++ b/Sprint-1/implement/sum.js @@ -1,4 +1,11 @@ function sum(elements) { + // If input is not an array, return 0 (least surprising behaviour) + if (!Array.isArray(elements)) return 0; + + // Sum only numeric values + return elements.reduce((total, item) => { + return typeof item === "number" ? total + item : total; + }, 0); } module.exports = sum; diff --git a/Sprint-1/implement/sum.test.js b/Sprint-1/implement/sum.test.js index dd0a090ca..0ab3313e5 100644 --- a/Sprint-1/implement/sum.test.js +++ b/Sprint-1/implement/sum.test.js @@ -13,24 +13,41 @@ 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 one number, returns that number", () => { + expect(sum([7])).toBe(7); +}); // Given an array containing negative numbers // When passed to the sum function // Then it should still return the correct total sum +test("sums negative numbers correctly", () => { + expect(sum([-5, -10, 3])).toBe(-12); +}); // Given an array with decimal/float numbers // When passed to the sum function // Then it should return the correct total sum +test("sums decimal numbers correctly", () => { + expect(sum([1.5, 2.25, 3.25])).toBe(7); +}); // 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("ignores non-number values and sums only numbers", () => { + expect(sum(["hi", 10, "wow", 20, null, 5])).toBe(35); +}); // 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 only non-number values, returns 0", () => { + expect(sum(["a", {}, null, undefined])).toBe(0); +}); From 692e1dfa4ac16daff47c84cc33b6daf9ea3b21b9 Mon Sep 17 00:00:00 2001 From: Ali Date: Tue, 18 Nov 2025 23:56:01 +0000 Subject: [PATCH 6/7] Refactor: simplify includes function by using for...of loop --- Sprint-1/refactor/includes.js | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/Sprint-1/refactor/includes.js b/Sprint-1/refactor/includes.js index 29dad81f0..8c9ae2e66 100644 --- a/Sprint-1/refactor/includes.js +++ b/Sprint-1/refactor/includes.js @@ -1,8 +1,7 @@ // 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]; + for (const element of list) { if (element === target) { return true; } From 36c4d0a569dc5aff909016ea9b4e90a1f323202e Mon Sep 17 00:00:00 2001 From: Ali Date: Thu, 20 Nov 2025 20:36:45 +0000 Subject: [PATCH 7/7] Fix: correct house number access in address object and update comments for clarity --- Sprint-2/debug/address.js | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/Sprint-2/debug/address.js b/Sprint-2/debug/address.js index 940a6af83..7a4b4a680 100644 --- a/Sprint-2/debug/address.js +++ b/Sprint-2/debug/address.js @@ -1,4 +1,8 @@ // Predict and explain first... +// Prediction: The code will print "My house number is undefined". +// Explanation: The code uses address[0], but address is an object, not an array. +// Objects cannot be accessed using numeric indexes. Therefore address[0] does not exist +// and evaluates to undefined. // This code should log out the houseNumber from the address object // but it isn't working... @@ -12,4 +16,5 @@ const address = { postcode: "XYZ 123", }; -console.log(`My house number is ${address[0]}`); +console.log(`My house number is ${address.houseNumber}`); +// Expected output: My house number is 42 \ No newline at end of file