From a7538540c54478c21f2dae757f639b96d324dc48 Mon Sep 17 00:00:00 2001 From: Niangh Ciang Date: Mon, 6 Jul 2026 13:38:38 +0100 Subject: [PATCH 01/10] Fixed median.js implementation --- 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..2984d724c 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; + if (!Array.isArray(list)) { + return null; + } + const numbersOnly = list.filter((value) => typeof value === "number"); + + if (numbersOnly.length === 0) { + return null; + } + + const sortedList = [...numbersOnly].sort((a, b) => a - b); + + const middleIndex = Math.floor(sortedList.length / 2); + + if (sortedList.length % 2 !== 0) { + return sortedList[middleIndex]; + } else { + const firstMiddle = sortedList[middleIndex - 1]; + const secondMiddle = sortedList[middleIndex]; + return (firstMiddle + secondMiddle) / 2; + } } module.exports = calculateMedian; From 3cbe8a919f205529d6cafb25c286a18f7123006f Mon Sep 17 00:00:00 2001 From: Niangh Ciang Date: Mon, 6 Jul 2026 14:08:52 +0100 Subject: [PATCH 02/10] Add dedupe tests --- Sprint-1/implement/dedupe.test.js | 53 +++++++++++++++++++++++++------ 1 file changed, 43 insertions(+), 10 deletions(-) diff --git a/Sprint-1/implement/dedupe.test.js b/Sprint-1/implement/dedupe.test.js index d7c8e3d8e..b7a91e057 100644 --- a/Sprint-1/implement/dedupe.test.js +++ b/Sprint-1/implement/dedupe.test.js @@ -14,15 +14,48 @@ E.g. dedupe([1, 2, 1]) returns [1, 2] // Acceptance Criteria: // 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"); +describe("dedupe", () => { + test("returns an empty array when passed 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 + // Given an array with no duplicates + test("returns a copy of the original array when there are no duplicates", () => { + expect(dedupe([1, 2, 3])).toEqual([1, 2, 3]); + expect(dedupe(["a", "b", "c"])).toEqual(["a", "b", "c"]); + expect(dedupe(["apple", "banana", "cherry"])).toEqual([ + "apple", + "banana", + "cherry", + ]); + }); -// 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. + // Given an array of strings or numbers + test("removes duplicates from an array of numbers", () => { + expect(dedupe([5, 1, 1, 2, 3, 2, 5, 8])).toEqual([5, 1, 2, 3, 8]); + expect(dedupe([1, 2, 1])).toEqual([1, 2]); + expect(dedupe([1, 1, 2, 2, 3, 3, 4, 4])).toEqual([1, 2, 3, 4]); + }); + test("removes duplicates from an array of strings", () => { + expect(dedupe(["a", "a", "a", "b", "b", "c"])).toEqual(["a", "b", "c"]); + expect( + dedupe(["apple", "banana", "apple", "banana", "cherry", "cherry"]) + ).toEqual(["apple", "banana", "cherry"]); + expect(dedupe(["cat", "dog", "cat", "bird"])).toEqual([ + "cat", + "dog", + "bird", + ]); + }); + // Given an array with mixed types + test("removes duplicates from an array with mixed types", () => { + expect(dedupe([1, "1", 2, "2", 1, "1"])).toEqual([1, "1", 2, "2"]); + expect(dedupe(["apple", 1, "banana", 2, "apple", 1])).toEqual([ + "apple", + 1, + "banana", + 2, + ]); + expect(dedupe([true, false, true, false])).toEqual([true, false]); + }); +}); From f22f510e28c0af5b9abcc5e7e89f0c9a451ffbc6 Mon Sep 17 00:00:00 2001 From: Niangh Ciang Date: Mon, 6 Jul 2026 14:21:24 +0100 Subject: [PATCH 03/10] Implement dedupe function --- Sprint-1/implement/dedupe.js | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/Sprint-1/implement/dedupe.js b/Sprint-1/implement/dedupe.js index 781e8718a..fab3d944f 100644 --- a/Sprint-1/implement/dedupe.js +++ b/Sprint-1/implement/dedupe.js @@ -1 +1,5 @@ -function dedupe() {} +function dedupe(array) { + if (!Array.isArray(array)) return []; + return [...new Set(array)]; +} +module.exports = dedupe; From 7b69ec926491a63a2362a18f34901404078ea87a Mon Sep 17 00:00:00 2001 From: Niangh Ciang Date: Mon, 6 Jul 2026 14:38:46 +0100 Subject: [PATCH 04/10] Add max tests --- Sprint-1/implement/max.test.js | 64 +++++++++++++++++++--------------- 1 file changed, 35 insertions(+), 29 deletions(-) diff --git a/Sprint-1/implement/max.test.js b/Sprint-1/implement/max.test.js index 82f18fd88..ebf95a49a 100644 --- a/Sprint-1/implement/max.test.js +++ b/Sprint-1/implement/max.test.js @@ -12,32 +12,38 @@ We have set things up already so that this file can see your function from the o const findMax = require("./max.js"); -// 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"); - -// Given an array with one number -// When passed to the max function -// Then it should return that number - -// Given an array with both positive and negative numbers -// When passed to the max function -// Then it should return the largest number overall - -// Given an array with just negative numbers -// When passed to the max function -// Then it should return the closest one to zero - -// Given an array with decimal numbers -// When passed to the max function -// Then it should return the largest decimal number - -// Given an array with non-number values -// When passed to the max function -// Then it should return the max and ignore non-numeric values - -// 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 +describe("findMax", () => { + test("returns -Infinity when passed an empty array", () => { + expect(findMax([])).toEqual(-Infinity); + }); + + // Given an array with one number + test("returns the number itself when passed an array with one number", () => { + expect(findMax([42])).toEqual(42); + }); + + // Given an array with both positive and negative numbers + test("returns the largest number with both positive and negative numbers", () => { + expect(findMax([-10, 0, 10, 20, -20])).toEqual(20); + }); + + // Given an array with just negative numbers + test("returns the largest number with negative numbers", () => { + expect(findMax([-10, -20, -30, -4, -8, -1])).toEqual(-1); + }); + + // Given an array with decimal numbers + test("returns the largest number with decimal numbers", () => { + expect(findMax([-5, 2.3, 7, 3.9, 2.1])).toEqual(3.9); + }); + + // Given an array with non-number values + test("returns the largest number when the array contains non-numeric values", () => { + expect(findMax(["hey", 10, "hi", 60, 10])).toEqual(60); + }); + + // Given an array with only non-number values + test("returns -Infinity when the array contains only non-numeric values", () => { + expect(findMax(["hey", "hi", "hello"])).toEqual(-Infinity); + }); +}); From 2e90135044f504428e25d2a2f07e37bbedf4d71d Mon Sep 17 00:00:00 2001 From: Niangh Ciang Date: Mon, 6 Jul 2026 14:46:09 +0100 Subject: [PATCH 05/10] Implement findMax and update tests --- Sprint-1/implement/max.js | 12 ++++++++++++ Sprint-1/implement/max.test.js | 2 +- 2 files changed, 13 insertions(+), 1 deletion(-) diff --git a/Sprint-1/implement/max.js b/Sprint-1/implement/max.js index 6dd76378e..53d8118be 100644 --- a/Sprint-1/implement/max.js +++ b/Sprint-1/implement/max.js @@ -1,4 +1,16 @@ function findMax(elements) { + if (!Array.isArray(elements)) return -Infinity; + let max = -Infinity; + + for (const element of elements) { + if (typeof element === "number") { + if (element > max) { + max = element; + } + } + } + + return max; } module.exports = findMax; diff --git a/Sprint-1/implement/max.test.js b/Sprint-1/implement/max.test.js index ebf95a49a..e097381aa 100644 --- a/Sprint-1/implement/max.test.js +++ b/Sprint-1/implement/max.test.js @@ -34,7 +34,7 @@ describe("findMax", () => { // Given an array with decimal numbers test("returns the largest number with decimal numbers", () => { - expect(findMax([-5, 2.3, 7, 3.9, 2.1])).toEqual(3.9); + expect(findMax([-5, 2.3, 7.5, 3.9, 2.1])).toEqual(7.5); }); // Given an array with non-number values From c03e93024a25ceac25a6a50b243d409fa616c461 Mon Sep 17 00:00:00 2001 From: Niangh Ciang Date: Mon, 6 Jul 2026 16:10:38 +0100 Subject: [PATCH 06/10] Add test suite for sum function --- Sprint-1/implement/sum.test.js | 61 ++++++++++++++++++++++------------ 1 file changed, 40 insertions(+), 21 deletions(-) diff --git a/Sprint-1/implement/sum.test.js b/Sprint-1/implement/sum.test.js index dd0a090ca..b619f4060 100644 --- a/Sprint-1/implement/sum.test.js +++ b/Sprint-1/implement/sum.test.js @@ -13,24 +13,43 @@ 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") - -// Given an array with just one number -// When passed to the sum function -// Then it should return that number - -// Given an array containing negative numbers -// When passed to the sum function -// Then it should still return the correct total sum - -// Given an array with decimal/float numbers -// When passed to the sum function -// Then it should return the correct total sum - -// 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 - -// 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 +describe("sum", () => { + test("returns 0 when passed an empty array", () => { + expect(sum([])).toEqual(0); + }); + + // Given an array with just one number + // When passed to the sum function + // Then it should return that number + test("returns the number itself when passed an array with one number", () => { + expect(sum([4])).toEqual(4); + }); + + // Given an array containing negative numbers + // When passed to the sum function + // Then it should still return the correct total sum + test("returns the correct total sum when passed an array with negative numbers", () => { + expect(sum([-10, 20, -30, 40])).toEqual(20); + }); + + // Given an array with decimal/float numbers + // When passed to the sum function + // Then it should return the correct total sum + test("returns the correct total sum when passed an array with decimal numbers", () => { + expect(sum([-5, 2.3, 7.5, 3.9, 2.1])).toEqual(10.8); + }); + + // 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("returns the correct total sum when passed an array with non-numeric values", () => { + expect(sum(["hey", 10, "hi", 60, 10])).toEqual(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("returns 0 when passed an array with only non-numeric values", () => { + expect(sum(["hello", "kitty", "cc"])).toEqual(0); + }); +}); From 650ead1470ebb4dbbde73c8cb97121e9bce3837f Mon Sep 17 00:00:00 2001 From: Niangh Ciang Date: Mon, 6 Jul 2026 16:24:13 +0100 Subject: [PATCH 07/10] Implement sum function --- Sprint-1/implement/sum.js | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/Sprint-1/implement/sum.js b/Sprint-1/implement/sum.js index 9062aafe3..c5f7589b9 100644 --- a/Sprint-1/implement/sum.js +++ b/Sprint-1/implement/sum.js @@ -1,4 +1,15 @@ function sum(elements) { + if (!Array.isArray(elements)) return 0; + + let total = 0; + + for (const element of elements) { + if (typeof element === "number") { + total += element; + } + } + total = Number(total.toFixed(2)); + return total; } module.exports = sum; From 7fd5ba84c90bee05121d743fe47b82e7b7607fd8 Mon Sep 17 00:00:00 2001 From: Niangh Ciang Date: Mon, 6 Jul 2026 16:31:22 +0100 Subject: [PATCH 08/10] Refactor includes implementation --- Sprint-1/refactor/includes.js | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) diff --git a/Sprint-1/refactor/includes.js b/Sprint-1/refactor/includes.js index 29dad81f0..01b696d05 100644 --- a/Sprint-1/refactor/includes.js +++ b/Sprint-1/refactor/includes.js @@ -1,6 +1,6 @@ // Refactor the implementation of includes to use a for...of loop -function includes(list, target) { +/*function includes(list, target) { for (let index = 0; index < list.length; index++) { const element = list[index]; if (element === target) { @@ -9,5 +9,15 @@ function includes(list, target) { } return false; } +*/ + +function includes(list, target) { + for (const element of list) { + if (element === target) { + return true; + } + } + return false; +} module.exports = includes; From 5467d65934dfcea58f5352ecd40fd6185b6be45b Mon Sep 17 00:00:00 2001 From: Niangh Ciang Date: Mon, 6 Jul 2026 19:15:12 +0100 Subject: [PATCH 09/10] Implement final frequency calculation --- Sprint-1/stretch/aoc-2018-day1/solution.js | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/Sprint-1/stretch/aoc-2018-day1/solution.js b/Sprint-1/stretch/aoc-2018-day1/solution.js index e69de29bb..45a36ef8c 100644 --- a/Sprint-1/stretch/aoc-2018-day1/solution.js +++ b/Sprint-1/stretch/aoc-2018-day1/solution.js @@ -0,0 +1,16 @@ +const fs = require("fs"); + +const raw = fs.readFileSync("input.txt", "utf8"); + +const lines = raw.split("\n"); +const numbers = lines.map(Number); +function findFinalFrequency(nums) { + let total = 0; + + for (const n of nums) { + total += n; + } + + return total; +} +console.log(findFinalFrequency(numbers)); From 1fbbc081e87e0634c2909afac3f2d9f3fd7d942b Mon Sep 17 00:00:00 2001 From: Niangh Ciang Date: Wed, 15 Jul 2026 12:15:02 +0100 Subject: [PATCH 10/10] Fix median filter for invalid numeric values --- Sprint-1/fix/median.js | 2 +- Sprint-1/fix/median.test.js | 26 +++++++++++++++++++++----- 2 files changed, 22 insertions(+), 6 deletions(-) diff --git a/Sprint-1/fix/median.js b/Sprint-1/fix/median.js index 2984d724c..9b4060437 100644 --- a/Sprint-1/fix/median.js +++ b/Sprint-1/fix/median.js @@ -9,7 +9,7 @@ function calculateMedian(list) { if (!Array.isArray(list)) { return null; } - const numbersOnly = list.filter((value) => typeof value === "number"); + const numbersOnly = list.filter(Number.isFinite); if (numbersOnly.length === 0) { return null; diff --git a/Sprint-1/fix/median.test.js b/Sprint-1/fix/median.test.js index 21da654d7..ceca2894d 100644 --- a/Sprint-1/fix/median.test.js +++ b/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 +35,21 @@ 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 (${val})`, () => expect(calculateMedian(val)).toBe(null)) + it("filters out NaN, Infinity, and -Infinity", () => { + expect(calculateMedian([NaN, Infinity, -Infinity, 1, 2, 3])).toEqual(2); + }); + + [ + "not an array", + 123, + null, + undefined, + {}, + [], + ["apple", null, undefined], + ].forEach((val) => + it(`returns null for non-numeric array (${val})`, () => + expect(calculateMedian(val)).toBe(null)) ); [ @@ -45,6 +60,7 @@ 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)) ); });