From f7ce2f5e57e9efa19655942a6b45f6fced5f6f5e Mon Sep 17 00:00:00 2001 From: TTiamiyu Date: Sun, 26 Jul 2026 09:27:55 +0100 Subject: [PATCH 01/13] Refactor calculateMedian function to handle non-array inputs and mixed values --- Sprint-1/fix/median.js | 21 ++++++++++++++++++--- 1 file changed, 18 insertions(+), 3 deletions(-) diff --git a/Sprint-1/fix/median.js b/Sprint-1/fix/median.js index b22590bc6..698f1fbcc 100644 --- a/Sprint-1/fix/median.js +++ b/Sprint-1/fix/median.js @@ -6,9 +6,24 @@ // 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; + if (!Array.isArray(list)) { + return null; + } + + const numbers = list.filter((item) => typeof item === "number"); + + if (numbers.length === 0) { + return null; + } + + const sorted = [...numbers].sort((a, b) => a - b); + const middleIndex = Math.floor(sorted.length / 2); + + if (sorted.length % 2 === 0) { + return (sorted[middleIndex - 1] + sorted[middleIndex]) / 2; + } else { + return sorted[middleIndex]; + } } module.exports = calculateMedian; From 25d86f085842a75f4d77bec72a311a5d54cc20cd Mon Sep 17 00:00:00 2001 From: TTiamiyu Date: Sun, 26 Jul 2026 10:10:47 +0100 Subject: [PATCH 02/13] Implement dedupe function and add tests for empty and unique arrays --- Sprint-1/implement/dedupe.js | 6 +++++- Sprint-1/implement/dedupe.test.js | 10 ++++++++-- 2 files changed, 13 insertions(+), 3 deletions(-) diff --git a/Sprint-1/implement/dedupe.js b/Sprint-1/implement/dedupe.js index 781e8718a..f3905db2a 100644 --- a/Sprint-1/implement/dedupe.js +++ b/Sprint-1/implement/dedupe.js @@ -1 +1,5 @@ -function dedupe() {} +function dedupe(list) { + return list.filter((item, index) => index === list.indexOf(item)); +} + +module.exports = dedupe; diff --git a/Sprint-1/implement/dedupe.test.js b/Sprint-1/implement/dedupe.test.js index d7c8e3d8e..019850797 100644 --- a/Sprint-1/implement/dedupe.test.js +++ b/Sprint-1/implement/dedupe.test.js @@ -16,7 +16,13 @@ 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, it returns an empty array", () => { + expect(dedupe([])).toEqual([]); +}); + +test("given an array with no duplicates, it returns a copy of the original array", () => { + expect(dedupe([1, 2, 3])).toEqual([1, 2, 3]); +}); // Given an array with no duplicates // When passed to the dedupe function @@ -24,5 +30,5 @@ test.todo("given an empty array, it returns an empty array"); // 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. From 520177486f81491b841ff7bbed110eb6148f75a7 Mon Sep 17 00:00:00 2001 From: TTiamiyu Date: Sun, 26 Jul 2026 10:27:07 +0100 Subject: [PATCH 03/13] Add test for empty array case in max function --- Sprint-1/implement/max.test.js | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/Sprint-1/implement/max.test.js b/Sprint-1/implement/max.test.js index 82f18fd88..4f5620078 100644 --- a/Sprint-1/implement/max.test.js +++ b/Sprint-1/implement/max.test.js @@ -16,7 +16,9 @@ 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 From 4e5a380c8ce5613e1c957c261ccc8f352cc92bb0 Mon Sep 17 00:00:00 2001 From: TTiamiyu Date: Sun, 26 Jul 2026 11:04:12 +0100 Subject: [PATCH 04/13] Add tests for various scenarios in max function --- Sprint-1/implement/max.test.js | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) diff --git a/Sprint-1/implement/max.test.js b/Sprint-1/implement/max.test.js index 4f5620078..8fa5f2388 100644 --- a/Sprint-1/implement/max.test.js +++ b/Sprint-1/implement/max.test.js @@ -24,22 +24,41 @@ test("given an empty array, returns -Infinity", () => { // When passed to the max function // Then it should return that number +test("given an array with one number, returns the number", () => { + expected(findMax([12])).toBe(12); +}); + // 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 highest number", () => { + expect(findMax([20, -21, 30])).toBe(30); +}); // 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, return the number closest to zero", () => { + expect(findMax([-12, -7, -20])).toBe(-7); +}); // 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, return the largest decimal number", () => { + expect(findMax([1.2, 1.3, 1.8])).toBe(1.8); +}); // 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, return the max and ignore the non-numerical values", () => { + expect(findMax(["boy", 2, "hi", 20, 24])).toBe(24); +}); // 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, return the least surprising value", () => { + expect(findMax(["a", "c", "e"])).toBe(-Infinity); +}); From 1c07c6162fff8b68185e25ea0ba755827e4e824c Mon Sep 17 00:00:00 2001 From: TTiamiyu Date: Sun, 26 Jul 2026 11:32:11 +0100 Subject: [PATCH 05/13] Fix findMax function to correctly filter non-numeric values and update test case for consistency --- Sprint-1/implement/max.js | 2 ++ Sprint-1/implement/max.test.js | 2 +- 2 files changed, 3 insertions(+), 1 deletion(-) diff --git a/Sprint-1/implement/max.js b/Sprint-1/implement/max.js index 6dd76378e..106bb3278 100644 --- a/Sprint-1/implement/max.js +++ b/Sprint-1/implement/max.js @@ -1,4 +1,6 @@ function findMax(elements) { + const numbers = elements.filter((item) => typeof item === "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 8fa5f2388..2d1aa7cf6 100644 --- a/Sprint-1/implement/max.test.js +++ b/Sprint-1/implement/max.test.js @@ -25,7 +25,7 @@ test("given an empty array, returns -Infinity", () => { // Then it should return that number test("given an array with one number, returns the number", () => { - expected(findMax([12])).toBe(12); + expect(findMax([12])).toBe(12); }); // Given an array with both positive and negative numbers From c52700ab7b5ec5330f6d96998eec4dea4651cbdb Mon Sep 17 00:00:00 2001 From: TTiamiyu Date: Sun, 26 Jul 2026 12:13:21 +0100 Subject: [PATCH 06/13] Implement tests for sum function to cover various scenarios including empty array, single number, negative numbers, decimal numbers, and non-number values --- Sprint-1/implement/sum.test.js | 21 ++++++++++++++++++--- 1 file changed, 18 insertions(+), 3 deletions(-) diff --git a/Sprint-1/implement/sum.test.js b/Sprint-1/implement/sum.test.js index dd0a090ca..d665c6998 100644 --- a/Sprint-1/implement/sum.test.js +++ b/Sprint-1/implement/sum.test.js @@ -13,24 +13,39 @@ 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(); +}); // Given an array with just one number // When passed to the sum function // Then it should return that number +test("given an array with one number, return the 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("given an array with negative numbers, return the correct sum total", () => { + expect(sum([-1, -2, -3])).toBe(-6); +}); // 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/float numbers, return the correct sum total", () => { + expect(sum([1.1, 1.2, 2.1])).toBeCloseTo(4.4); +}); // 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, return correct sum total and ignore the non-numbers", () => { + expect(sum(["we", 2, "are", 18])).toBe(20); +}); // 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, return the least surprising value", () => { + expect(sum(["the", "world"])).toBe(0); +}); From 0667c52363d946d7a80f82296a9425e15c8de3ea Mon Sep 17 00:00:00 2001 From: TTiamiyu Date: Sun, 26 Jul 2026 12:32:41 +0100 Subject: [PATCH 07/13] Fix sum function test to return 0 for empty array case --- Sprint-1/implement/sum.test.js | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/Sprint-1/implement/sum.test.js b/Sprint-1/implement/sum.test.js index d665c6998..531be9bf5 100644 --- a/Sprint-1/implement/sum.test.js +++ b/Sprint-1/implement/sum.test.js @@ -14,7 +14,7 @@ const sum = require("./sum.js"); // When passed to the sum function // Then it should return 0 test("given an empty array, returns 0", () => { - expect(sum([])).toBe(); + expect(sum([])).toBe(0); }); // Given an array with just one number From 7d6ad3c4642d6ee9378cd4393da80af0bf39c98d Mon Sep 17 00:00:00 2001 From: TTiamiyu Date: Sun, 26 Jul 2026 12:32:52 +0100 Subject: [PATCH 08/13] Refactor sum function to filter non-numeric values and ensure correct summation --- Sprint-1/implement/sum.js | 2 ++ 1 file changed, 2 insertions(+) diff --git a/Sprint-1/implement/sum.js b/Sprint-1/implement/sum.js index 9062aafe3..f94529ebd 100644 --- a/Sprint-1/implement/sum.js +++ b/Sprint-1/implement/sum.js @@ -1,4 +1,6 @@ function sum(elements) { + const numbers = elements.filter((item) => typeof item === "number"); + return numbers.reduce((total, current) => total + current, 0); } module.exports = sum; From 2abe1ec659a4025c43500994bead3ebf716fdfef Mon Sep 17 00:00:00 2001 From: TTiamiyu Date: Sun, 26 Jul 2026 13:02:29 +0100 Subject: [PATCH 09/13] Refactor includes function to use for...of loop for improved readability --- 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 21c4d2a322d8a7e4ae0ce43440e1433aca844a75 Mon Sep 17 00:00:00 2001 From: TTiamiyu Date: Fri, 31 Jul 2026 22:17:25 +0100 Subject: [PATCH 10/13] Refactor dedupe tests to improve clarity and structure in case of future changes. --- Sprint-1/implement/dedupe.test.js | 28 ++++++++++++++++++++++++---- 1 file changed, 24 insertions(+), 4 deletions(-) diff --git a/Sprint-1/implement/dedupe.test.js b/Sprint-1/implement/dedupe.test.js index 019850797..fb5829000 100644 --- a/Sprint-1/implement/dedupe.test.js +++ b/Sprint-1/implement/dedupe.test.js @@ -20,15 +20,35 @@ test("given an empty array, it returns an empty array", () => { expect(dedupe([])).toEqual([]); }); -test("given an array with no duplicates, it returns a copy of the original array", () => { - expect(dedupe([1, 2, 3])).toEqual([1, 2, 3]); -}); - // 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", () => { + const input = [1, 2, 3]; + const result = dedupe(input); + + expect(result).toEqual(input); + expect(result).not.toBe(input); +}); + // 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("given an array of numbers with duplicates, it returns a new array with duplicates removed preserving first occurrences", () => { + const input = [5, 1, 1, 2, 3, 2, 5, 8]; + const result = dedupe(input); + + expect(result).toEqual([5, 1, 2, 3, 8]); + expect(result).not.toBe(input); +}); + +test("given an array of strings with duplicates, it returns a new array with duplicates removed preserving first occurrences", () => { + const input = ["a", "a", "a", "b", "b", "c"]; + const result = dedupe(input); + + expect(result).toEqual(["a", "b", "c"]); + expect(result).not.toBe(input); +}); From 4b9ea66c40d948a7c42082d808a9f305b8ad5ce8 Mon Sep 17 00:00:00 2001 From: TTiamiyu Date: Fri, 31 Jul 2026 22:27:40 +0100 Subject: [PATCH 11/13] Update max function test to include string representation of numbers --- Sprint-1/implement/max.test.js | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/Sprint-1/implement/max.test.js b/Sprint-1/implement/max.test.js index 2d1aa7cf6..ab496c492 100644 --- a/Sprint-1/implement/max.test.js +++ b/Sprint-1/implement/max.test.js @@ -53,7 +53,7 @@ test("given an array with decimal numbers, return the largest decimal number", ( // 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, return the max and ignore the non-numerical values", () => { - expect(findMax(["boy", 2, "hi", 20, 24])).toBe(24); + expect(findMax(["boy", 2, "hi", 20, "120", 24])).toBe(24); }); // Given an array with only non-number values From 87afb14a78b567dfa33f73d086185fb3aa8c8e5c Mon Sep 17 00:00:00 2001 From: TTiamiyu Date: Fri, 31 Jul 2026 22:48:31 +0100 Subject: [PATCH 12/13] Enhance sum function to filter out NaN values for accurate summation --- Sprint-1/implement/sum.js | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/Sprint-1/implement/sum.js b/Sprint-1/implement/sum.js index f94529ebd..3d1f5610a 100644 --- a/Sprint-1/implement/sum.js +++ b/Sprint-1/implement/sum.js @@ -1,5 +1,7 @@ function sum(elements) { - const numbers = elements.filter((item) => typeof item === "number"); + const numbers = elements.filter( + (item) => typeof item === "number" && !Number.isNaN(item) + ); return numbers.reduce((total, current) => total + current, 0); } From b70a0a4f8b1e6ea85c0d3eef0527c8706a42eba9 Mon Sep 17 00:00:00 2001 From: TTiamiyu Date: Fri, 31 Jul 2026 22:48:48 +0100 Subject: [PATCH 13/13] Add tests for NaN handling and Infinity cases in sum function --- Sprint-1/implement/sum.test.js | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/Sprint-1/implement/sum.test.js b/Sprint-1/implement/sum.test.js index 531be9bf5..38a5307c0 100644 --- a/Sprint-1/implement/sum.test.js +++ b/Sprint-1/implement/sum.test.js @@ -49,3 +49,16 @@ test("given an array containing non-number values, return correct sum total and test("given an array with only non-number values, return the least surprising value", () => { expect(sum(["the", "world"])).toBe(0); }); +// Given an array containing NaN and valid numbers +// When passed to the sum function +// Then it should ignore NaN and sum the valid numbers +test("given an array containing NaN, ignores NaN and returns the sum of valid numbers", () => { + expect(sum([NaN, 1])).toBe(1); +}); + +// Given an array with positive and negative Infinity +// When passed to the sum function +// Then it should return NaN (undefined mathematical operation) +test("given an array with Infinity and -Infinity, returns NaN", () => { + expect(sum([Infinity, -Infinity])).toBeNaN(); +});