From 6e09b6448d76fef3e0693cfe6867562779773f23 Mon Sep 17 00:00:00 2001
From: iswat <ibeetek@gmail.com>
Date: Thu, 23 Oct 2025 12:07:07 +0100
Subject: [PATCH 01/64] Add initial mean.js and mean.test.js files

---
 prep/mean.js      | 9 +++++++++
 prep/mean.test.js | 7 +++++++
 2 files changed, 16 insertions(+)
 create mode 100644 prep/mean.js
 create mode 100644 prep/mean.test.js

diff --git a/prep/mean.js b/prep/mean.js
new file mode 100644
index 000000000..485efedb8
--- /dev/null
+++ b/prep/mean.js
@@ -0,0 +1,9 @@
+function calculateMean(list) {
+    let total = 0;
+     
+    for (const item of list) {
+        total += item;
+    }
+}
+
+calculateMean([1,2,3,4,5]);
\ No newline at end of file
diff --git a/prep/mean.test.js b/prep/mean.test.js
new file mode 100644
index 000000000..cac7bfbfa
--- /dev/null
+++ b/prep/mean.test.js
@@ -0,0 +1,7 @@
+Test("Calculate the average of a list of numbers", () => {
+  const list = [3, 50, 7];
+  const currentOutput = calculateMean(list);
+  const targetOutput = 20; // 20 is (3 + 50 + 7) / 3
+  
+  expect(currentOutput).toEqual(targetOutput);
+});

From 49b82d5e422e6703f028ff69669b697aea6145a7 Mon Sep 17 00:00:00 2001
From: iswat <ibeetek@gmail.com>
Date: Thu, 23 Oct 2025 12:30:58 +0100
Subject: [PATCH 02/64] Write a test for the function in the median.js file.

---
 prep/median.test.js | 7 +++++++
 1 file changed, 7 insertions(+)
 create mode 100644 prep/median.test.js

diff --git a/prep/median.test.js b/prep/median.test.js
new file mode 100644
index 000000000..5f8ef9c1e
--- /dev/null
+++ b/prep/median.test.js
@@ -0,0 +1,7 @@
+test("Calculate the median of the list of numbers", () => {
+    list = [10, 20, 30, 40, 50];
+    const currentOutput = calaculateMedian(list);
+    const targetOutput = 30;
+
+    expect(currentOutput).toEqual(targetOutput);
+})
\ No newline at end of file

From 94d5edf356155dbd76115de580146991b7ca2f38 Mon Sep 17 00:00:00 2001
From: iswat <ibeetek@gmail.com>
Date: Thu, 23 Oct 2025 12:57:24 +0100
Subject: [PATCH 03/64] Implement calculateMedian function

---
 prep/median.js | 6 ++++++
 1 file changed, 6 insertions(+)
 create mode 100644 prep/median.js

diff --git a/prep/median.js b/prep/median.js
new file mode 100644
index 000000000..5961bed42
--- /dev/null
+++ b/prep/median.js
@@ -0,0 +1,6 @@
+function calculateMedian(list) {
+    const middleIndex = Math.floor(list.length / 2);
+    const median = list.splice(middleIndex, 1)[0];
+
+    return median;
+}
\ No newline at end of file

From b6b20602775cfae82cf5f22c6343e838530af319 Mon Sep 17 00:00:00 2001
From: iswat <ibeetek@gmail.com>
Date: Fri, 24 Oct 2025 10:21:30 +0100
Subject: [PATCH 04/64] Add functions, extra code, and explanatory comments to
 mean-median.js about arrays as reference types

---
 prep/mean-median.js | 53 +++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 53 insertions(+)
 create mode 100644 prep/mean-median.js

diff --git a/prep/mean-median.js b/prep/mean-median.js
new file mode 100644
index 000000000..c79e65573
--- /dev/null
+++ b/prep/mean-median.js
@@ -0,0 +1,53 @@
+function calculateMean(list) {
+  let total = 0;
+
+  for (const item of list) {
+    total += item;
+  }
+  console.log("the total of the array is", total);
+  console.log("the element has",list.length, "elements");
+  return (total/list.length);
+  
+}
+
+function calculateMedian(list) {
+  const middleIndex = Math.floor(list.length / 2);
+  const median = list.splice(middleIndex, 1)[0]; // Because the splice method has been used on the variable list, 
+  // the array stored in memory will change, and any variable that points to it will show the updated array.
+
+  return median;
+}
+
+const salaries = [10, 20, 30, 40, 60, 80, 80]; 
+const median = calculateMedian(salaries);
+
+console.log(salaries, "<--- salaries input before we call calculateMean");
+const mean = calculateMean(salaries);
+
+console.log(`The median of the salaries is ${median}`);
+console.log(`The mean of the salaries is ${mean}`);
+console.log(salaries);
+
+// Notes to understand Array as a reference type
+// 1. Arrays are reference types
+
+// This means that when you create an array like this:
+// const salaries = [10, 20, 30, 40, 60, 80, 80];
+// JavaScript doesn’t store the array itself directly in the variable salaries.
+
+// Instead, the array is stored somewhere in memory, and salaries holds a reference (or pointer) to that memory location.
+// 2. What “reference” means
+
+// Think of it like this: the array is a house, and salaries is the address of that house.
+
+// If you write:
+// const other = salaries;
+// now other has the same address. Both salaries and other point to the same array in memory.
+
+// 3. Implication: modifying the array
+
+// Because both variables point to the same array, changing it through one variable affects the other:
+// other[0] = 100;
+// console.log(salaries[0]); // 100
+// This happens because there is only one array in memory, and both variables reference it.
+

From 935e47ed28c003f1ecdbe7ca2bb8d3818a3de012 Mon Sep 17 00:00:00 2001
From: iswat <ibeetek@gmail.com>
Date: Fri, 24 Oct 2025 10:25:37 +0100
Subject: [PATCH 05/64] Add a return statement to the function calculateMean

---
 prep/mean.js | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/prep/mean.js b/prep/mean.js
index 485efedb8..b6fcc88f0 100644
--- a/prep/mean.js
+++ b/prep/mean.js
@@ -4,6 +4,9 @@ function calculateMean(list) {
     for (const item of list) {
         total += item;
     }
+    console.log("the total of the array is", total);
+    console.log("the element has", list.length, "elements");
+    return total / list.length;
 }
 
 calculateMean([1,2,3,4,5]);
\ No newline at end of file

From dfe0f4434ae9bfd1137326d901a1589f1199664d Mon Sep 17 00:00:00 2001
From: iswat <ibeetek@gmail.com>
Date: Fri, 24 Oct 2025 16:05:08 +0100
Subject: [PATCH 06/64] Export function to test file using module.exports

---
 prep/mean.js   | 4 +++-
 prep/median.js | 4 +++-
 2 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/prep/mean.js b/prep/mean.js
index b6fcc88f0..de9d6f4d7 100644
--- a/prep/mean.js
+++ b/prep/mean.js
@@ -9,4 +9,6 @@ function calculateMean(list) {
     return total / list.length;
 }
 
-calculateMean([1,2,3,4,5]);
\ No newline at end of file
+//calculateMean([1,2,3,4,5]);
+
+module.exports = calculateMean;
\ No newline at end of file
diff --git a/prep/median.js b/prep/median.js
index 5961bed42..c30ccddd4 100644
--- a/prep/median.js
+++ b/prep/median.js
@@ -3,4 +3,6 @@ function calculateMedian(list) {
     const median = list.splice(middleIndex, 1)[0];
 
     return median;
-}
\ No newline at end of file
+}
+
+module.exports = calculateMedian;
\ No newline at end of file

From 22abc47946189c101917a77af63b9c1e7fc1bd83 Mon Sep 17 00:00:00 2001
From: iswat <ibeetek@gmail.com>
Date: Fri, 24 Oct 2025 16:07:16 +0100
Subject: [PATCH 07/64] Import calculateMean function from mean.js

---
 prep/mean.test.js | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/prep/mean.test.js b/prep/mean.test.js
index cac7bfbfa..4123bf07e 100644
--- a/prep/mean.test.js
+++ b/prep/mean.test.js
@@ -1,4 +1,6 @@
-Test("Calculate the average of a list of numbers", () => {
+const calculateMean = require("./mean");
+
+test("Calculate the average of a list of numbers", () => {
   const list = [3, 50, 7];
   const currentOutput = calculateMean(list);
   const targetOutput = 20; // 20 is (3 + 50 + 7) / 3

From e0bed316dfe739315cf391e660e7ef7ca1f75506 Mon Sep 17 00:00:00 2001
From: iswat <ibeetek@gmail.com>
Date: Fri, 24 Oct 2025 16:07:36 +0100
Subject: [PATCH 08/64] Import calculateMedian function from median.js

---
 prep/median.test.js | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/prep/median.test.js b/prep/median.test.js
index 5f8ef9c1e..5e9695e63 100644
--- a/prep/median.test.js
+++ b/prep/median.test.js
@@ -1,7 +1,13 @@
+const calaculateMedian = require("./median");
+
 test("Calculate the median of the list of numbers", () => {
-    list = [10, 20, 30, 40, 50];
+    const list = [10, 20, 30, 40, 50];
     const currentOutput = calaculateMedian(list);
     const targetOutput = 30;
 
     expect(currentOutput).toEqual(targetOutput);
-})
\ No newline at end of file
+})
+
+// test("should not mutate the list of numbers", () => {
+//     const list = 
+// })
\ No newline at end of file

From e092070074e48f4c7c1027c1f3c0cd64233fa12a Mon Sep 17 00:00:00 2001
From: iswat <ibeetek@gmail.com>
Date: Fri, 24 Oct 2025 16:08:38 +0100
Subject: [PATCH 09/64] Add package.json file

---
 prep/package.json | 13 +++++++++++++
 1 file changed, 13 insertions(+)
 create mode 100644 prep/package.json

diff --git a/prep/package.json b/prep/package.json
new file mode 100644
index 000000000..8cf1fc5ab
--- /dev/null
+++ b/prep/package.json
@@ -0,0 +1,13 @@
+{
+  "devDependencies": {
+    "jest": "^30.2.0"
+  },
+  "scripts": {
+    "test": "jest"
+  }
+}
+
+
+  
+
+

From 4fe7d13636b6365c327ea6f75ab734203000f15f Mon Sep 17 00:00:00 2001
From: iswat <ibeetek@gmail.com>
Date: Sun, 26 Oct 2025 19:25:59 +0000
Subject: [PATCH 10/64] Comment out function that mutates array with splice

---
 prep/median.js | 22 ++++++++++++++++------
 1 file changed, 16 insertions(+), 6 deletions(-)

diff --git a/prep/median.js b/prep/median.js
index c30ccddd4..8f91e67a5 100644
--- a/prep/median.js
+++ b/prep/median.js
@@ -1,8 +1,18 @@
-function calculateMedian(list) {
-    const middleIndex = Math.floor(list.length / 2);
-    const median = list.splice(middleIndex, 1)[0];
+// How to calculate the median of an array by mutating the array
 
-    return median;
-}
+// function calculateMedian(list) {
+//   const middleIndex = Math.floor(list.length / 2);
+//   const median = list.splice(middleIndex, 1)[0];
+//   console.log("middleIndex", middleIndex);
+//   console.log(list);
+//   return median;
+// }
+
+// const actualOutput = calculateMedian([1, 2, 3]);
+// console.log("median", actualOutput);
+module.exports = calculateMedian;
 
-module.exports = calculateMedian;
\ No newline at end of file
+// How to calculate the median of an array without muatating the array
+function calculateMedian(list) {
+  const arrayLength = list.length;
+}

From f72964348947972503419c8e8809d107a5c0c782 Mon Sep 17 00:00:00 2001
From: iswat <ibeetek@gmail.com>
Date: Mon, 27 Oct 2025 10:44:46 +0000
Subject: [PATCH 11/64] Add function to calculate median without mutating the
 array

This implementation handles arrays with an odd length.
---
 prep/median.js | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/prep/median.js b/prep/median.js
index 8f91e67a5..11cd3d86c 100644
--- a/prep/median.js
+++ b/prep/median.js
@@ -14,5 +14,15 @@ module.exports = calculateMedian;
 
 // How to calculate the median of an array without muatating the array
 function calculateMedian(list) {
-  const arrayLength = list.length;
+  let median = "no implementation for this test case yet";
+  const arrayLength = list.length; // 3
+  if (arrayLength % 2 !== 0) {
+    const lengthDividedByTwo = Math.floor(arrayLength / 2);
+    median = lengthDividedByTwo;
+
+  }
+  return list[median];
 }
+
+const actualOutput = calculateMedian([10, 20, 30, 40, 50]);
+console.log("median", actualOutput);
\ No newline at end of file

From 3449f32621c5f610dad32f16f2d07e3c271cbf68 Mon Sep 17 00:00:00 2001
From: iswat <ibeetek@gmail.com>
Date: Mon, 27 Oct 2025 11:03:06 +0000
Subject: [PATCH 12/64] Add Jest test case to verify that the function
 implementation does not mutate the array

---
 prep/median.test.js | 22 +++++++++++++---------
 1 file changed, 13 insertions(+), 9 deletions(-)

diff --git a/prep/median.test.js b/prep/median.test.js
index 5e9695e63..b260117c7 100644
--- a/prep/median.test.js
+++ b/prep/median.test.js
@@ -1,13 +1,17 @@
-const calaculateMedian = require("./median");
+const calculateMedian = require("./median");
 
 test("Calculate the median of the list of numbers", () => {
-    const list = [10, 20, 30, 40, 50];
-    const currentOutput = calaculateMedian(list);
-    const targetOutput = 30;
+  const list = [10, 20, 30, 40, 50];
+  const currentOutput = calculateMedian(list);
+  const targetOutput = 30;
 
-    expect(currentOutput).toEqual(targetOutput);
-})
+  expect(currentOutput).toEqual(targetOutput);
+});
+
+test("should not modify the input", () => {
+  const list = [1, 2, 3];
+  calculateMedian(list);
+
+  expect(list).toEqual([1, 2, 3]);
+});
 
-// test("should not mutate the list of numbers", () => {
-//     const list = 
-// })
\ No newline at end of file

From 696f20b6a908334bfe40cfc4fffe93f0f265f4e6 Mon Sep 17 00:00:00 2001
From: iswat <ibeetek@gmail.com>
Date: Thu, 30 Oct 2025 22:10:42 +0000
Subject: [PATCH 13/64] Add a Jest test case to check that calculateMedian
 returns the correct median for an even-length array

---
 prep/median.test.js | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/prep/median.test.js b/prep/median.test.js
index b260117c7..9f407df2b 100644
--- a/prep/median.test.js
+++ b/prep/median.test.js
@@ -10,8 +10,17 @@ test("Calculate the median of the list of numbers", () => {
 
 test("should not modify the input", () => {
   const list = [1, 2, 3];
-  calculateMedian(list);
+  const currentOutput = calculateMedian(list);
 
-  expect(list).toEqual([1, 2, 3]);
+  expect(currentOutput).toEqual(2);
 });
 
+test(
+  "should return the average of the two middle numbers as the median for an array with even length",
+  () => {
+    const list = [2, 6, 4, 3];
+    const currentOutput = calculateMedian(list);
+    expect(currentOutput).toEqual(5);
+  }
+);
+

From 2bf9d3cd33f7d09734b8e89485bea75695872448 Mon Sep 17 00:00:00 2001
From: iswat <ibeetek@gmail.com>
Date: Thu, 30 Oct 2025 22:42:33 +0000
Subject: [PATCH 14/64] Update function implementation to handle even-length
 arrays when calculating the median

---
 prep/median.js | 23 ++++++++++++++++-------
 1 file changed, 16 insertions(+), 7 deletions(-)

diff --git a/prep/median.js b/prep/median.js
index 11cd3d86c..d89688342 100644
--- a/prep/median.js
+++ b/prep/median.js
@@ -14,15 +14,24 @@ module.exports = calculateMedian;
 
 // How to calculate the median of an array without muatating the array
 function calculateMedian(list) {
-  let median = "no implementation for this test case yet";
+  let medianIndex;
+  let actualMedian;
   const arrayLength = list.length; // 3
   if (arrayLength % 2 !== 0) {
-    const lengthDividedByTwo = Math.floor(arrayLength / 2);
-    median = lengthDividedByTwo;
-
+    medianIndex = (arrayLength + 1) / 2;
+    console.log(medianIndex - 1);
+    actualMedian = list[medianIndex - 1];
+  } 
+  else {
+  medianIndex = (arrayLength) / 2;
+  console.log(medianIndex);
+  firstMedianIndex = list[medianIndex - 1];
+  secondMedianIndex = list[medianIndex];
+  actualMedian = (firstMedianIndex + secondMedianIndex) / 2
+  
   }
-  return list[median];
+  return actualMedian;
 }
 
-const actualOutput = calculateMedian([10, 20, 30, 40, 50]);
-console.log("median", actualOutput);
\ No newline at end of file
+const actualOutput = calculateMedian([10, 20, 30, 50]);
+console.log("median", actualOutput);

From f658cab3ba40187b26133d675865f4bcfe8d8f34 Mon Sep 17 00:00:00 2001
From: iswat <ibeetek@gmail.com>
Date: Thu, 30 Oct 2025 22:47:57 +0000
Subject: [PATCH 15/64] Remove function call and console.log debugging
 statements

---
 prep/median.js | 18 ++++++------------
 1 file changed, 6 insertions(+), 12 deletions(-)

diff --git a/prep/median.js b/prep/median.js
index d89688342..d008917bb 100644
--- a/prep/median.js
+++ b/prep/median.js
@@ -19,19 +19,13 @@ function calculateMedian(list) {
   const arrayLength = list.length; // 3
   if (arrayLength % 2 !== 0) {
     medianIndex = (arrayLength + 1) / 2;
-    console.log(medianIndex - 1);
     actualMedian = list[medianIndex - 1];
-  } 
-  else {
-  medianIndex = (arrayLength) / 2;
-  console.log(medianIndex);
-  firstMedianIndex = list[medianIndex - 1];
-  secondMedianIndex = list[medianIndex];
-  actualMedian = (firstMedianIndex + secondMedianIndex) / 2
-  
+  } else {
+    medianIndex = arrayLength / 2;
+
+    firstMedianIndex = list[medianIndex - 1];
+    secondMedianIndex = list[medianIndex];
+    actualMedian = (firstMedianIndex + secondMedianIndex) / 2;
   }
   return actualMedian;
 }
-
-const actualOutput = calculateMedian([10, 20, 30, 50]);
-console.log("median", actualOutput);

From 7ecf9490c8a3c2fee9864e75e0fd8933846b3150 Mon Sep 17 00:00:00 2001
From: iswat <ibeetek@gmail.com>
Date: Thu, 30 Oct 2025 22:51:17 +0000
Subject: [PATCH 16/64] Fix inconsistent indentation in jest test

---
 prep/median.test.js | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/prep/median.test.js b/prep/median.test.js
index 9f407df2b..b0ed64d2d 100644
--- a/prep/median.test.js
+++ b/prep/median.test.js
@@ -15,12 +15,10 @@ test("should not modify the input", () => {
   expect(currentOutput).toEqual(2);
 });
 
-test(
-  "should return the average of the two middle numbers as the median for an array with even length",
-  () => {
+test("should return the average of the two middle numbers as the median for an array with even length", () => {
     const list = [2, 6, 4, 3];
     const currentOutput = calculateMedian(list);
-    expect(currentOutput).toEqual(5);
+    expect(currentOutput).toEqual(5)
   }
 );
 

From c217567c79a7aa918879a4d997ffea0e24592f8c Mon Sep 17 00:00:00 2001
From: iswat <ibeetek@gmail.com>
Date: Mon, 3 Nov 2025 16:41:58 +0000
Subject: [PATCH 17/64] Add input validation to return null when a non-array is
 passed

---
 Sprint-1/fix/median.js | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/Sprint-1/fix/median.js b/Sprint-1/fix/median.js
index b22590bc6..ff8a86d67 100644
--- a/Sprint-1/fix/median.js
+++ b/Sprint-1/fix/median.js
@@ -6,9 +6,16 @@
 // 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;
+  // Check that the input passed to the function calculateMeddian is an array
+  if (!Array.isArray(list)) {
+    return null;
+  }
+
+  if (list.length % 2 !== 0) {
+    const middleIndex = Math.floor(list.length / 2);
+    const median = list.splice(middleIndex, 1)[0];
+    return median;
+  }
 }
 
 module.exports = calculateMedian;

From d75a3ce2d0cea771d49c78b4be3e86ce5ef35707 Mon Sep 17 00:00:00 2001
From: iswat <ibeetek@gmail.com>
Date: Mon, 3 Nov 2025 16:47:05 +0000
Subject: [PATCH 18/64] Reformat median test suite for readability

- Adjusted indentation and arrow function formatting
- Added consistent line breaks and spacing
- No changes to test logic or order
---
 Sprint-1/fix/median.test.js | 22 +++++++++++++++++-----
 1 file changed, 17 insertions(+), 5 deletions(-)

diff --git a/Sprint-1/fix/median.test.js b/Sprint-1/fix/median.test.js
index 21da654d7..c262c3776 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 +35,17 @@ 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 (${val})`, () => expect(calculateMedian(val)).toBe(null))
+  [
+    "not an array",
+    123,
+    null,
+    undefined,
+    {},
+    [],
+    ["apple", null, undefined],
+  ].forEach((val) =>
+    it(`returns null for non-numeric array (${val})`, () =>
+      expect(calculateMedian(val)).toBe(null))
   );
 
   [
@@ -45,6 +56,7 @@ 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))
   );
 });

From 4040d9b15fb7cfe2b0f27c52b64358d41a3a34d5 Mon Sep 17 00:00:00 2001
From: iswat <ibeetek@gmail.com>
Date: Mon, 3 Nov 2025 21:46:37 +0000
Subject: [PATCH 19/64] Add validation to ensure input is an array

---
 Sprint-1/fix/median.js | 8 ++------
 1 file changed, 2 insertions(+), 6 deletions(-)

diff --git a/Sprint-1/fix/median.js b/Sprint-1/fix/median.js
index ff8a86d67..c3bcc3167 100644
--- a/Sprint-1/fix/median.js
+++ b/Sprint-1/fix/median.js
@@ -6,16 +6,12 @@
 // or 'list' has mixed values (the function is expected to sort only numbers).
 
 function calculateMedian(list) {
-  // Check that the input passed to the function calculateMeddian is an array
+  // this statement checks that the input passed to the function calculateMeddian is an array
   if (!Array.isArray(list)) {
     return null;
   }
 
-  if (list.length % 2 !== 0) {
-    const middleIndex = Math.floor(list.length / 2);
-    const median = list.splice(middleIndex, 1)[0];
-    return median;
-  }
+ 
 }
 
 module.exports = calculateMedian;

From 57c20f41e06e1a0c9891efc40cc0cac4dd34ba09 Mon Sep 17 00:00:00 2001
From: iswat <ibeetek@gmail.com>
Date: Mon, 3 Nov 2025 21:48:50 +0000
Subject: [PATCH 20/64] Filter out non-numeric values from the array and assign
 its reference to the `validNumbers`

---
 Sprint-1/fix/median.js | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/Sprint-1/fix/median.js b/Sprint-1/fix/median.js
index c3bcc3167..0f0f6b9f5 100644
--- a/Sprint-1/fix/median.js
+++ b/Sprint-1/fix/median.js
@@ -11,7 +11,10 @@ function calculateMedian(list) {
     return null;
   }
 
- 
+  // this statement filters valid numbers and make variable validNumbers to hold a reference to the new array
+  const validNumbers = list.filter(
+    (item) => typeof item === "number" && !isNaN(item)
+  );
 }
 
 module.exports = calculateMedian;

From 8a413462c1b3f55b5dcf1ec77d2cf3823801742f Mon Sep 17 00:00:00 2001
From: iswat <ibeetek@gmail.com>
Date: Mon, 3 Nov 2025 21:53:48 +0000
Subject: [PATCH 21/64] Add statements to duplicate the input array and sort it
 in ascending order

---
 Sprint-1/fix/median.js | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/Sprint-1/fix/median.js b/Sprint-1/fix/median.js
index 0f0f6b9f5..7e1c01330 100644
--- a/Sprint-1/fix/median.js
+++ b/Sprint-1/fix/median.js
@@ -15,6 +15,19 @@ function calculateMedian(list) {
   const validNumbers = list.filter(
     (item) => typeof item === "number" && !isNaN(item)
   );
+
+  // This statement returns `null` if the length of the array is strictly equals to zero
+  // i.e empty array or invalid array
+  if (validNumbers.length === 0) {
+    return null;
+  }
+
+  // this statement creates a copy of the array and variable copyArray will hold a reference to the new array
+  const copyArray = validNumbers.slice();
+
+  // this statement uses sort function to arrange the elements in the array in ascending order.
+  //  sort function mutates the `copyArray` so, sortArray and copyArray hold reference to the same array in memory
+  const sortArray = copyArray.sort((a, b) => a - b);
 }
 
 module.exports = calculateMedian;

From 17d40f7e0de3e553df05edf06b4f99462d3f0ecc Mon Sep 17 00:00:00 2001
From: iswat <ibeetek@gmail.com>
Date: Mon, 3 Nov 2025 21:58:20 +0000
Subject: [PATCH 22/64] Add logic to calculate the median for arrays with odd
 or even lengths

---
 Sprint-1/fix/median.js | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/Sprint-1/fix/median.js b/Sprint-1/fix/median.js
index 7e1c01330..59fd0fc33 100644
--- a/Sprint-1/fix/median.js
+++ b/Sprint-1/fix/median.js
@@ -28,6 +28,20 @@ function calculateMedian(list) {
   // this statement uses sort function to arrange the elements in the array in ascending order.
   //  sort function mutates the `copyArray` so, sortArray and copyArray hold reference to the same array in memory
   const sortArray = copyArray.sort((a, b) => a - b);
+
+  // this statement divides the length of `sortArray` by 2, rounds it down to the
+  // nearest whole number, and assigns it to `middleIndex`
+  const middleIndex = Math.floor(sortArray.length / 2);
+
+  // this statement checks if `sortArray` has an odd number of elements, and if so, returns the middle element
+  if (sortArray.length % 2 !== 0) {
+    return sortArray[middleIndex];
+  } else {
+    // this statement checks if `sortArray` has an even number of length
+    const firstMiddleIndex = sortArray[middleIndex - 1];
+    const secondMiddleIndex = sortArray[middleIndex];
+    return (firstMiddleIndex + secondMiddleIndex) / 2;
+  }
 }
 
 module.exports = calculateMedian;

From a22309d089c6688d311325436112393a12e8cbe3 Mon Sep 17 00:00:00 2001
From: iswat <ibeetek@gmail.com>
Date: Mon, 3 Nov 2025 22:18:58 +0000
Subject: [PATCH 23/64] Add test case to ensure `dedupe` returns an empty array
 for empty input

---
 Sprint-1/implement/dedupe.test.js | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/Sprint-1/implement/dedupe.test.js b/Sprint-1/implement/dedupe.test.js
index 23e0f8638..8754fdaa0 100644
--- a/Sprint-1/implement/dedupe.test.js
+++ b/Sprint-1/implement/dedupe.test.js
@@ -25,3 +25,12 @@ test.todo("given an empty array, it returns an empty 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
+
+describe("dedupe", () => {
+  test("returns an empty array when given an empty array", () => {
+    const inputArray = [];
+    const actualOutput = dedupe(inputArray);
+    const expectedOutput = [];
+    expect(actualOutput).toStrictEqual(expectedOutput);
+  });
+});

From 8d1429815d08fff3c0ed529481de0a9ca5b54183 Mon Sep 17 00:00:00 2001
From: iswat <ibeetek@gmail.com>
Date: Mon, 3 Nov 2025 22:21:44 +0000
Subject: [PATCH 24/64] Make function accessible in other files by adding
 module.exports

---
 Sprint-1/implement/dedupe.js | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/Sprint-1/implement/dedupe.js b/Sprint-1/implement/dedupe.js
index 781e8718a..bfd8f1d0f 100644
--- a/Sprint-1/implement/dedupe.js
+++ b/Sprint-1/implement/dedupe.js
@@ -1 +1,8 @@
-function dedupe() {}
+function dedupe(arrayInput) {
+    if (arrayInput.length === 0) {
+        return [];
+    }
+}
+
+
+module.exports = dedupe;
\ No newline at end of file

From 50670f0d915f2726e246e0fcd024aceac9fbdc9a Mon Sep 17 00:00:00 2001
From: iswat <ibeetek@gmail.com>
Date: Mon, 3 Nov 2025 22:52:02 +0000
Subject: [PATCH 25/64] Add test case for `dedupe` to ensure it returns a copy
 of the array when input has no duplicates

---
 Sprint-1/implement/dedupe.test.js | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/Sprint-1/implement/dedupe.test.js b/Sprint-1/implement/dedupe.test.js
index 8754fdaa0..53cd83c2b 100644
--- a/Sprint-1/implement/dedupe.test.js
+++ b/Sprint-1/implement/dedupe.test.js
@@ -31,6 +31,13 @@ describe("dedupe", () => {
     const inputArray = [];
     const actualOutput = dedupe(inputArray);
     const expectedOutput = [];
-    expect(actualOutput).toStrictEqual(expectedOutput);
+    expect(actualOutput).toEqual(expectedOutput);
   });
+
+  test("returns a copy of the original array when there is no duplicates", () => {
+    const inputArray = [1, 2, 3];
+    const actualOutput = dedupe(inputArray);
+    const expectedOutput = [1, 2, 3];
+    expect(actualOutput).toEqual(expectedOutput);
+  })
 });

From 63e538fcb095a334f7de27f4166870d37b355350 Mon Sep 17 00:00:00 2001
From: iswat <ibeetek@gmail.com>
Date: Tue, 4 Nov 2025 11:37:13 +0000
Subject: [PATCH 26/64] Refactor test cases to data-driven format using an
 array and loop

---
 Sprint-1/implement/dedupe.test.js | 28 +++++++++++++++-------------
 1 file changed, 15 insertions(+), 13 deletions(-)

diff --git a/Sprint-1/implement/dedupe.test.js b/Sprint-1/implement/dedupe.test.js
index 53cd83c2b..d1ab64bd1 100644
--- a/Sprint-1/implement/dedupe.test.js
+++ b/Sprint-1/implement/dedupe.test.js
@@ -27,17 +27,19 @@ test.todo("given an empty array, it returns an empty array");
 // Then it should remove the duplicate values, preserving the first occurence of each element
 
 describe("dedupe", () => {
-  test("returns an empty array when given an empty array", () => {
-    const inputArray = [];
-    const actualOutput = dedupe(inputArray);
-    const expectedOutput = [];
-    expect(actualOutput).toEqual(expectedOutput);
-  });
-
-  test("returns a copy of the original array when there is no duplicates", () => {
-    const inputArray = [1, 2, 3];
-    const actualOutput = dedupe(inputArray);
-    const expectedOutput = [1, 2, 3];
-    expect(actualOutput).toEqual(expectedOutput);
-  })
+  [{ input: [], expected: [] }].forEach(({ input, expected }) =>
+    test(`returns an empty array for input [${input}]`, () =>
+      expect(dedupe(input)).toEqual(expected))
+  );
+
+  [{ input: [1, 2, 3], expected: [1, 2, 3] }].forEach(({ input, expected }) =>
+    test(`returns a copy of the array when no duplicates exist for input [${input}]`, () =>
+      expect(dedupe(input)).toEqual(expected))
+  );
+
+  [{ input: [5, 1, 1, 2, 3, 2, 5, 8], expected: [5, 1, 2, 3, 8] }].forEach(
+    ({ input, expected }) =>
+      test(`removes duplicate elements and keep the first occurrence for [${input}]`, () =>
+        expect(dedupe(input)).toEqual(expected))
+  );
 });

From 950a4a3817c16239700da8de14b11bafe8dde3d0 Mon Sep 17 00:00:00 2001
From: iswat <ibeetek@gmail.com>
Date: Tue, 4 Nov 2025 12:07:17 +0000
Subject: [PATCH 27/64] Add test case to ensure dedupe removes duplicates and
 keeps the first occurrence for arrays of strings and numbers

---
 Sprint-1/implement/dedupe.test.js | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/Sprint-1/implement/dedupe.test.js b/Sprint-1/implement/dedupe.test.js
index d1ab64bd1..e1c68b78a 100644
--- a/Sprint-1/implement/dedupe.test.js
+++ b/Sprint-1/implement/dedupe.test.js
@@ -42,4 +42,10 @@ describe("dedupe", () => {
       test(`removes duplicate elements and keep the first occurrence for [${input}]`, () =>
         expect(dedupe(input)).toEqual(expected))
   );
+
+  [{ input: ["1", 1, "1", 1], expected: ["1", 1] }].forEach(
+    ({ input, expected }) =>
+      test(`removes duplicates from an array of numbers and strings, keeping the first occurrence of each element, for the input [${input}]`, () =>
+        expect(dedupe(input)).toEqual(expected))
+  );
 });

From 37d11330007058809de72619f7af25d559299a2c Mon Sep 17 00:00:00 2001
From: iswat <ibeetek@gmail.com>
Date: Tue, 4 Nov 2025 12:08:36 +0000
Subject: [PATCH 28/64] Comment out unused test.todo

---
 Sprint-1/implement/dedupe.test.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Sprint-1/implement/dedupe.test.js b/Sprint-1/implement/dedupe.test.js
index e1c68b78a..82028f0a6 100644
--- a/Sprint-1/implement/dedupe.test.js
+++ b/Sprint-1/implement/dedupe.test.js
@@ -16,7 +16,7 @@ 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.todo("given an empty array, it returns an empty array");
 
 // Given an array with no duplicates
 // When passed to the dedupe function

From 1f1729105dc77b72bbc9bcf9c4c52b24aef5ebac Mon Sep 17 00:00:00 2001
From: iswat <ibeetek@gmail.com>
Date: Tue, 4 Nov 2025 12:26:10 +0000
Subject: [PATCH 29/64] Add additional test cases for  no duplicates, duplicate
 and mixed string-number array handling

---
 Sprint-1/implement/dedupe.test.js | 28 +++++++++++++++++++---------
 1 file changed, 19 insertions(+), 9 deletions(-)

diff --git a/Sprint-1/implement/dedupe.test.js b/Sprint-1/implement/dedupe.test.js
index 82028f0a6..8ca52de2d 100644
--- a/Sprint-1/implement/dedupe.test.js
+++ b/Sprint-1/implement/dedupe.test.js
@@ -32,20 +32,30 @@ describe("dedupe", () => {
       expect(dedupe(input)).toEqual(expected))
   );
 
-  [{ input: [1, 2, 3], expected: [1, 2, 3] }].forEach(({ input, expected }) =>
+  [
+    { input: [1, 2, 3], expected: [1, 2, 3] },
+    { input: ["a", "b", "car"], expected: ["a", "b", "car"] },
+    { input: [0, 1, 5, 6], expected: [0, 1, 5, 6]},
+  ].forEach(({ input, expected }) =>
     test(`returns a copy of the array when no duplicates exist for input [${input}]`, () =>
       expect(dedupe(input)).toEqual(expected))
   );
 
-  [{ input: [5, 1, 1, 2, 3, 2, 5, 8], expected: [5, 1, 2, 3, 8] }].forEach(
-    ({ input, expected }) =>
-      test(`removes duplicate elements and keep the first occurrence for [${input}]`, () =>
-        expect(dedupe(input)).toEqual(expected))
+  [
+    { input: [5, 1, 1, 2, 3, 2, 5, 8], expected: [5, 1, 2, 3, 8] },
+    { input: [1, 1, 1, 1], expected: [1] },
+    { input: ["a", "a", "a", "b", "b", "c"], expected: ["a", "b", "c"]},
+
+  ].forEach(({ input, expected }) =>
+    test(`removes duplicate elements and keep the first occurrence for [${input}]`, () =>
+      expect(dedupe(input)).toEqual(expected))
   );
 
-  [{ input: ["1", 1, "1", 1], expected: ["1", 1] }].forEach(
-    ({ input, expected }) =>
-      test(`removes duplicates from an array of numbers and strings, keeping the first occurrence of each element, for the input [${input}]`, () =>
-        expect(dedupe(input)).toEqual(expected))
+  [
+    { input: ["1", 1, "1", 1], expected: ["1", 1] },
+    { input: [2, "3", "hello", 5], expected: [2, "3", "hello", 5]},
+  ].forEach(({ input, expected }) =>
+    test(`removes duplicates from an array of numbers and strings, keeping the first occurrence of each element, for the input [${input}]`, () =>
+      expect(dedupe(input)).toEqual(expected))
   );
 });

From a73b980260327673e17eed813df9a96d0cd9c993 Mon Sep 17 00:00:00 2001
From: iswat <ibeetek@gmail.com>
Date: Tue, 4 Nov 2025 13:03:59 +0000
Subject: [PATCH 30/64] Add case to verify dedupe removes invalid elements and
 duplicates, returning a new array

---
 Sprint-1/implement/dedupe.test.js | 18 +++++++++++++-----
 1 file changed, 13 insertions(+), 5 deletions(-)

diff --git a/Sprint-1/implement/dedupe.test.js b/Sprint-1/implement/dedupe.test.js
index 8ca52de2d..4065f9910 100644
--- a/Sprint-1/implement/dedupe.test.js
+++ b/Sprint-1/implement/dedupe.test.js
@@ -35,7 +35,7 @@ describe("dedupe", () => {
   [
     { input: [1, 2, 3], expected: [1, 2, 3] },
     { input: ["a", "b", "car"], expected: ["a", "b", "car"] },
-    { input: [0, 1, 5, 6], expected: [0, 1, 5, 6]},
+    { input: [0, 1, 5, 6], expected: [0, 1, 5, 6] },
   ].forEach(({ input, expected }) =>
     test(`returns a copy of the array when no duplicates exist for input [${input}]`, () =>
       expect(dedupe(input)).toEqual(expected))
@@ -44,8 +44,7 @@ describe("dedupe", () => {
   [
     { input: [5, 1, 1, 2, 3, 2, 5, 8], expected: [5, 1, 2, 3, 8] },
     { input: [1, 1, 1, 1], expected: [1] },
-    { input: ["a", "a", "a", "b", "b", "c"], expected: ["a", "b", "c"]},
-
+    { input: ["a", "a", "a", "b", "b", "c"], expected: ["a", "b", "c"] },
   ].forEach(({ input, expected }) =>
     test(`removes duplicate elements and keep the first occurrence for [${input}]`, () =>
       expect(dedupe(input)).toEqual(expected))
@@ -53,9 +52,18 @@ describe("dedupe", () => {
 
   [
     { input: ["1", 1, "1", 1], expected: ["1", 1] },
-    { input: [2, "3", "hello", 5], expected: [2, "3", "hello", 5]},
+    { input: [2, "3", "hello", 5], expected: [2, "3", "hello", 5] },
   ].forEach(({ input, expected }) =>
     test(`removes duplicates from an array of numbers and strings, keeping the first occurrence of each element, for the input [${input}]`, () =>
-      expect(dedupe(input)).toEqual(expected))
+      expect(dedupe(input)).toEqual(expected));
+  );
+
+  [
+    { input: [1, 2, true, 3, null, "a", {}], expected: [1, 2, 3, "a"] },
+    { input: ["x", undefined, "x", "y", []], expected: ["x", "y"] },
+    { input: [false, 5, 5, "hello", () => {}, 5], expected: [5, "hello"] },
+  ].forEach(({ input, expected }) =>
+    test(`Ensures dedupe filters out invalid elements, removes duplicates, and returns a copy of the array`, () =>
+      expect(dedupe(input)).toEqual(expected));
   );
 });

From 4ea5009bf14c38049b2655e64711eaf49fd5ac18 Mon Sep 17 00:00:00 2001
From: iswat <ibeetek@gmail.com>
Date: Tue, 4 Nov 2025 13:10:45 +0000
Subject: [PATCH 31/64] Remove the semi-colon after the expect expression

---
 Sprint-1/implement/dedupe.test.js | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/Sprint-1/implement/dedupe.test.js b/Sprint-1/implement/dedupe.test.js
index 4065f9910..fc2916ed0 100644
--- a/Sprint-1/implement/dedupe.test.js
+++ b/Sprint-1/implement/dedupe.test.js
@@ -55,7 +55,7 @@ describe("dedupe", () => {
     { input: [2, "3", "hello", 5], expected: [2, "3", "hello", 5] },
   ].forEach(({ input, expected }) =>
     test(`removes duplicates from an array of numbers and strings, keeping the first occurrence of each element, for the input [${input}]`, () =>
-      expect(dedupe(input)).toEqual(expected));
+      expect(dedupe(input)).toEqual(expected))
   );
 
   [
@@ -64,6 +64,6 @@ describe("dedupe", () => {
     { input: [false, 5, 5, "hello", () => {}, 5], expected: [5, "hello"] },
   ].forEach(({ input, expected }) =>
     test(`Ensures dedupe filters out invalid elements, removes duplicates, and returns a copy of the array`, () =>
-      expect(dedupe(input)).toEqual(expected));
+      expect(dedupe(input)).toEqual(expected))
   );
 });

From e8bda7b7776f67385f8ac10c0a25bda20bedda93 Mon Sep 17 00:00:00 2001
From: iswat <ibeetek@gmail.com>
Date: Tue, 4 Nov 2025 13:27:08 +0000
Subject: [PATCH 32/64] Add test case in invalid elements category to ensure
 NaN is ignored

---
 Sprint-1/implement/dedupe.test.js | 1 +
 1 file changed, 1 insertion(+)

diff --git a/Sprint-1/implement/dedupe.test.js b/Sprint-1/implement/dedupe.test.js
index fc2916ed0..70ce45dab 100644
--- a/Sprint-1/implement/dedupe.test.js
+++ b/Sprint-1/implement/dedupe.test.js
@@ -62,6 +62,7 @@ describe("dedupe", () => {
     { input: [1, 2, true, 3, null, "a", {}], expected: [1, 2, 3, "a"] },
     { input: ["x", undefined, "x", "y", []], expected: ["x", "y"] },
     { input: [false, 5, 5, "hello", () => {}, 5], expected: [5, "hello"] },
+    { input: [1, NaN, 2, NaN, "hello"], expected: [1, NaN, 2, NaN, "hello"] },
   ].forEach(({ input, expected }) =>
     test(`Ensures dedupe filters out invalid elements, removes duplicates, and returns a copy of the array`, () =>
       expect(dedupe(input)).toEqual(expected))

From c5249d99a28c8cf5d303c27b5b66e1d88cda9773 Mon Sep 17 00:00:00 2001
From: iswat <ibeetek@gmail.com>
Date: Tue, 4 Nov 2025 13:39:04 +0000
Subject: [PATCH 33/64] Rename describe block to 'dedupe - valid inputs'

---
 Sprint-1/implement/dedupe.test.js | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/Sprint-1/implement/dedupe.test.js b/Sprint-1/implement/dedupe.test.js
index 70ce45dab..424ceaa23 100644
--- a/Sprint-1/implement/dedupe.test.js
+++ b/Sprint-1/implement/dedupe.test.js
@@ -26,7 +26,7 @@ E.g. dedupe([1, 2, 1]) target output: [1, 2]
 // When passed to the dedupe function
 // Then it should remove the duplicate values, preserving the first occurence of each element
 
-describe("dedupe", () => {
+describe("dedupe - valid inputs", () => {
   [{ input: [], expected: [] }].forEach(({ input, expected }) =>
     test(`returns an empty array for input [${input}]`, () =>
       expect(dedupe(input)).toEqual(expected))
@@ -67,4 +67,6 @@ describe("dedupe", () => {
     test(`Ensures dedupe filters out invalid elements, removes duplicates, and returns a copy of the array`, () =>
       expect(dedupe(input)).toEqual(expected))
   );
+
+
 });

From e95f6a4955bb5fb5d92cf024d2b8061bdb4f6c0e Mon Sep 17 00:00:00 2001
From: iswat <ibeetek@gmail.com>
Date: Tue, 4 Nov 2025 16:00:15 +0000
Subject: [PATCH 34/64] Add describe block for invalid inputs and a test case
 to ensure dedupe returns expected output

---
 Sprint-1/implement/dedupe.test.js | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/Sprint-1/implement/dedupe.test.js b/Sprint-1/implement/dedupe.test.js
index 424ceaa23..2b678997d 100644
--- a/Sprint-1/implement/dedupe.test.js
+++ b/Sprint-1/implement/dedupe.test.js
@@ -67,6 +67,15 @@ describe("dedupe - valid inputs", () => {
     test(`Ensures dedupe filters out invalid elements, removes duplicates, and returns a copy of the array`, () =>
       expect(dedupe(input)).toEqual(expected))
   );
+});
 
+describe("dedupe - invalid inputs", () => {
+const invalidInputs = [null, undefined, 123, "string", {}, () => {}];
 
+invalidInputs.forEach((input) => 
+  test(`throws typeError when input is ${String(input)}`, () => {
+    expect(dedupe(input)).toThrow(TypeError);
+    expect(dedupe(input)).toThrow("Input must be an array")
+  })
+)
 });

From 4e105a65c367d5c1fd533a254b3163e9047188e8 Mon Sep 17 00:00:00 2001
From: iswat <ibeetek@gmail.com>
Date: Wed, 5 Nov 2025 12:52:55 +0000
Subject: [PATCH 35/64] Remove the if statement that checks if length of the
 array is equlas to zero

---
 Sprint-1/implement/dedupe.js | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/Sprint-1/implement/dedupe.js b/Sprint-1/implement/dedupe.js
index bfd8f1d0f..db804c573 100644
--- a/Sprint-1/implement/dedupe.js
+++ b/Sprint-1/implement/dedupe.js
@@ -1,7 +1,5 @@
 function dedupe(arrayInput) {
-    if (arrayInput.length === 0) {
-        return [];
-    }
+   
 }
 
 

From ae9fb0ecc9cee19079f6c6c6004b570d61c2b0c1 Mon Sep 17 00:00:00 2001
From: iswat <ibeetek@gmail.com>
Date: Wed, 5 Nov 2025 13:49:06 +0000
Subject: [PATCH 36/64] Add input validation for non-array values

---
 Sprint-1/implement/dedupe.js | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/Sprint-1/implement/dedupe.js b/Sprint-1/implement/dedupe.js
index db804c573..85b03dddb 100644
--- a/Sprint-1/implement/dedupe.js
+++ b/Sprint-1/implement/dedupe.js
@@ -1,6 +1,9 @@
 function dedupe(arrayInput) {
-   
+   if (!Array.isArray(arrayInput)) {
+    throw new TypeError("Input must be an array");
+   }
 }
 
+console.log(dedupe("food"));
 
 module.exports = dedupe;
\ No newline at end of file

From 54e1a28b410da1df8581df79963d6fb130c2a364 Mon Sep 17 00:00:00 2001
From: iswat <ibeetek@gmail.com>
Date: Wed, 5 Nov 2025 13:54:18 +0000
Subject: [PATCH 37/64] Add implementation for when empty array is passed as
 input

---
 Sprint-1/implement/dedupe.js | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/Sprint-1/implement/dedupe.js b/Sprint-1/implement/dedupe.js
index 85b03dddb..47e061829 100644
--- a/Sprint-1/implement/dedupe.js
+++ b/Sprint-1/implement/dedupe.js
@@ -2,6 +2,10 @@ function dedupe(arrayInput) {
    if (!Array.isArray(arrayInput)) {
     throw new TypeError("Input must be an array");
    }
+
+   if (arrayInput.length === 0) {
+    return [];
+   }
 }
 
 console.log(dedupe("food"));

From 52e97c6ef803bbc5668004cf0626f0bd7fc34e2a Mon Sep 17 00:00:00 2001
From: iswat <ibeetek@gmail.com>
Date: Thu, 6 Nov 2025 09:47:55 +0000
Subject: [PATCH 38/64] Update dedupe test cases for correct expected output

- Remove NaN elements from expected outputs
- Add missing element 5 in the test input for a duplicate case
- Wrap dedupe function calls in a function so Jest can catch thrown errors
---
 Sprint-1/implement/dedupe.test.js | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/Sprint-1/implement/dedupe.test.js b/Sprint-1/implement/dedupe.test.js
index 2b678997d..a67597eb9 100644
--- a/Sprint-1/implement/dedupe.test.js
+++ b/Sprint-1/implement/dedupe.test.js
@@ -52,7 +52,7 @@ describe("dedupe - valid inputs", () => {
 
   [
     { input: ["1", 1, "1", 1], expected: ["1", 1] },
-    { input: [2, "3", "hello", 5], expected: [2, "3", "hello", 5] },
+    { input: [2, "3", "hello", 5, 5], expected: [2, "3", "hello", 5] },
   ].forEach(({ input, expected }) =>
     test(`removes duplicates from an array of numbers and strings, keeping the first occurrence of each element, for the input [${input}]`, () =>
       expect(dedupe(input)).toEqual(expected))
@@ -62,7 +62,7 @@ describe("dedupe - valid inputs", () => {
     { input: [1, 2, true, 3, null, "a", {}], expected: [1, 2, 3, "a"] },
     { input: ["x", undefined, "x", "y", []], expected: ["x", "y"] },
     { input: [false, 5, 5, "hello", () => {}, 5], expected: [5, "hello"] },
-    { input: [1, NaN, 2, NaN, "hello"], expected: [1, NaN, 2, NaN, "hello"] },
+    { input: [1, NaN, 2, NaN, "hello"], expected: [1,  2, "hello"] },
   ].forEach(({ input, expected }) =>
     test(`Ensures dedupe filters out invalid elements, removes duplicates, and returns a copy of the array`, () =>
       expect(dedupe(input)).toEqual(expected))
@@ -74,8 +74,9 @@ const invalidInputs = [null, undefined, 123, "string", {}, () => {}];
 
 invalidInputs.forEach((input) => 
   test(`throws typeError when input is ${String(input)}`, () => {
-    expect(dedupe(input)).toThrow(TypeError);
-    expect(dedupe(input)).toThrow("Input must be an array")
+    expect(() => dedupe(null)).toThrow(TypeError);
+    expect(() => dedupe(null)).toThrow("Input must be an array");
+
   })
 )
 });

From ba0eff32fb98ba4ea51eebe6f4a12060448c094a Mon Sep 17 00:00:00 2001
From: iswat <ibeetek@gmail.com>
Date: Thu, 6 Nov 2025 09:54:28 +0000
Subject: [PATCH 39/64] Implement dedupe function to remove duplicate numbers
 and strings, filter out invalid elements, and return a new array preserving
 first occurrences

---
 Sprint-1/implement/dedupe.js | 27 +++++++++++++++++++++------
 1 file changed, 21 insertions(+), 6 deletions(-)

diff --git a/Sprint-1/implement/dedupe.js b/Sprint-1/implement/dedupe.js
index 47e061829..56772a912 100644
--- a/Sprint-1/implement/dedupe.js
+++ b/Sprint-1/implement/dedupe.js
@@ -1,13 +1,28 @@
 function dedupe(arrayInput) {
-   if (!Array.isArray(arrayInput)) {
+  if (!Array.isArray(arrayInput)) {
     throw new TypeError("Input must be an array");
-   }
+  }
 
-   if (arrayInput.length === 0) {
+  if (arrayInput.length === 0) {
     return [];
-   }
+  }
+
+  const newArray = [];
+  const seen = new Set();
+
+  for (const item of arrayInput) {
+    if (
+      (typeof item === "number" && !Number.isNaN(item) || typeof item === "string") &&
+      !seen.has(item)
+    ) {
+      newArray.push(item);
+      seen.add(item);
+    }
+  }
+
+  return newArray;
 }
 
-console.log(dedupe("food"));
+console.log(dedupe([null, undefined]));
 
-module.exports = dedupe;
\ No newline at end of file
+module.exports = dedupe;

From 0da3ea8bd1b8a3ca8f38d683483e13d4f98099dd Mon Sep 17 00:00:00 2001
From: iswat <ibeetek@gmail.com>
Date: Thu, 6 Nov 2025 10:24:52 +0000
Subject: [PATCH 40/64] Refactor condition in dedupe for easier reading and
 parsing

- Reorganized the logical condition to improve readability
- Ensured number and string checks remain consistent
- Simplified the order of operations to make the logic clearer and easier to maintain
---
 Sprint-1/implement/dedupe.js | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/Sprint-1/implement/dedupe.js b/Sprint-1/implement/dedupe.js
index 56772a912..e212fe0e8 100644
--- a/Sprint-1/implement/dedupe.js
+++ b/Sprint-1/implement/dedupe.js
@@ -12,8 +12,9 @@ function dedupe(arrayInput) {
 
   for (const item of arrayInput) {
     if (
-      (typeof item === "number" && !Number.isNaN(item) || typeof item === "string") &&
-      !seen.has(item)
+      !seen.has(item) &&
+      ((typeof item === "number" && !Number.isNaN(item)) ||
+        typeof item === "string")
     ) {
       newArray.push(item);
       seen.add(item);

From a7e57bfb8174efd936a78b4e61634eabe475140d Mon Sep 17 00:00:00 2001
From: iswat <ibeetek@gmail.com>
Date: Thu, 6 Nov 2025 10:28:00 +0000
Subject: [PATCH 41/64] Remove console.log statement used for debugging

---
 Sprint-1/implement/dedupe.js | 2 --
 1 file changed, 2 deletions(-)

diff --git a/Sprint-1/implement/dedupe.js b/Sprint-1/implement/dedupe.js
index e212fe0e8..5403e0b57 100644
--- a/Sprint-1/implement/dedupe.js
+++ b/Sprint-1/implement/dedupe.js
@@ -24,6 +24,4 @@ function dedupe(arrayInput) {
   return newArray;
 }
 
-console.log(dedupe([null, undefined]));
-
 module.exports = dedupe;

From 06f06ed7ed5c03e03220d2e8a2c1777fc0fe4600 Mon Sep 17 00:00:00 2001
From: iswat <ibeetek@gmail.com>
Date: Thu, 6 Nov 2025 12:05:22 +0000
Subject: [PATCH 42/64] Add comments to clarify dedupe implementation

---
 Sprint-1/implement/dedupe.js | 30 +++++++++++++++++++++++-------
 1 file changed, 23 insertions(+), 7 deletions(-)

diff --git a/Sprint-1/implement/dedupe.js b/Sprint-1/implement/dedupe.js
index 5403e0b57..b7372b6e7 100644
--- a/Sprint-1/implement/dedupe.js
+++ b/Sprint-1/implement/dedupe.js
@@ -1,27 +1,43 @@
+// This defines a function named dedupe with a parameter arrayInput. arrayInput should be an array.
 function dedupe(arrayInput) {
+  // This checks whether the input is not an array.
   if (!Array.isArray(arrayInput)) {
+    // If the input is not an array, the function stops, throws a TypeError and shows an error message saying:“Input must be an array.”
     throw new TypeError("Input must be an array");
   }
-
+  // This checks if the array is empty (has no elements).
   if (arrayInput.length === 0) {
+    // If the array is empty, it returns an empty array.
     return [];
   }
 
+  // This declares a new variable `newArray` which will hold a reference to an empty array in memory
   const newArray = [];
-  const seen = new Set();
+  // This decares a new varibale `seen` which will hold a reference to the actual set object in memory
+  const seen = new Set(); // variable seen keeps track of all items that have already been added to the result array
+  // seen is a Set object that remembers items,
+
+  // newArray is an array that holds the actual result.
 
+  // This starts a loop that goes through each element in the input array one by one.
   for (const item of arrayInput) {
+    // This big condition checks two things before adding an item:
+
+    // !seen.has(item) — The item has not been added before.
+
+    // The item is either a number (but not NaN) or a string.
+    // So only real numbers and strings that haven’t appeared yet will be kept.
     if (
       !seen.has(item) &&
       ((typeof item === "number" && !Number.isNaN(item)) ||
         typeof item === "string")
     ) {
-      newArray.push(item);
-      seen.add(item);
+      newArray.push(item); // If the item passes the condition, it gets added to the new array.
+      seen.add(item); // The item is then recorded in the Set, so it won’t be added again later.
     }
   }
-
-  return newArray;
+  // After the loop finishes, return the final deduplicated array
+  return newArray; // After checking all items, the function returns the new array with duplicates removed and invalid items filtered out.
 }
 
-module.exports = dedupe;
+module.exports = dedupe; // This line allows the dedupe function to be used in other files (like the test file).

From b38a131b126a2899f344c0073afbd23bff95f725 Mon Sep 17 00:00:00 2001
From: iswat <ibeetek@gmail.com>
Date: Thu, 6 Nov 2025 12:44:02 +0000
Subject: [PATCH 43/64] Replace test.todo with actual test cases for findMax

- Implement tests for empty array, single number, positive/negative numbers,
  negative numbers only, decimal numbers, mixed non-numeric values, and only
  non-number values.
- Covers all scenarios described in the comments.
---
 Sprint-1/implement/max.test.js | 22 +++++++++++++++++++++-
 1 file changed, 21 insertions(+), 1 deletion(-)

diff --git a/Sprint-1/implement/max.test.js b/Sprint-1/implement/max.test.js
index 82f18fd88..d92793182 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([8])).toBe(8);
+});
 
 // 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, -5, 20, 0])).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, -5, -20])).toBe(-5);
+});
 
 // 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([1.1, 2.5, 0.3])).toBe(2.5);
+});
 
 // 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 ignore the non-numeric values", () => {
+  expect(findMax([10, "hi", 20, null])).toBe(20);
+});
 
 // 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", () => {
+  expect(findMax(["a", null, undefined])).toBe(-Infinity);
+});

From 110ef310e8efc8912f9cef071e2d38bd37c00dd8 Mon Sep 17 00:00:00 2001
From: iswat <ibeetek@gmail.com>
Date: Thu, 6 Nov 2025 13:47:04 +0000
Subject: [PATCH 44/64] Add tests for non-array inputs in findMax

---
 Sprint-1/implement/max.test.js | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/Sprint-1/implement/max.test.js b/Sprint-1/implement/max.test.js
index d92793182..fbc28d4e4 100644
--- a/Sprint-1/implement/max.test.js
+++ b/Sprint-1/implement/max.test.js
@@ -61,3 +61,18 @@ test("given an array with non-number values, returns the max and ignore the non-
 test("given an array with only non-number values", () => {
   expect(findMax(["a", null, undefined])).toBe(-Infinity);
 });
+
+// Edge cases
+// Given an array with non-array values
+// when passed to the max function
+// Then it should throw and error
+test("given a non-array input, throws a TypeError with message 'Input must be an array'", () => {
+  expect(() => findMax(42)).toThrow(new TypeError("Input must be an array"));
+  expect(() => findMax("hello")).toThrow(
+    new TypeError("Input must be an array")
+  );
+  expect(() => findMax(null)).toThrow(new TypeError("Input must be an array"));
+  expect(() => findMax(undefined)).toThrow(
+    new TypeError("Input must be an array")
+  );
+});

From 6e91a426e6cea3250bf45f806636699c6aafb242 Mon Sep 17 00:00:00 2001
From: iswat <ibeetek@gmail.com>
Date: Thu, 6 Nov 2025 22:44:17 +0000
Subject: [PATCH 45/64] Change deduplicate back to dedupe

---
 Sprint-1/implement/dedupe.test.js | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/Sprint-1/implement/dedupe.test.js b/Sprint-1/implement/dedupe.test.js
index a67597eb9..fd5207171 100644
--- a/Sprint-1/implement/dedupe.test.js
+++ b/Sprint-1/implement/dedupe.test.js
@@ -2,9 +2,9 @@ const dedupe = require("./dedupe.js");
 /*
 Dedupe Array
 
-📖 Dedupe means **deduplicate**
+📖 Dedupe means **dedupe**
 
-In this kata, you will need to deduplicate the elements of an array
+In this kata, you will need to dedupe the elements of an array
 
 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]

From bd49eed1f96029dcf01ed5f2706fc7f651ed7db6 Mon Sep 17 00:00:00 2001
From: iswat <ibeetek@gmail.com>
Date: Sun, 9 Nov 2025 10:41:49 +0000
Subject: [PATCH 46/64] Add findMax implementation for numeric arrays and
 handle empty array case

---
 Sprint-1/implement/max.js | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/Sprint-1/implement/max.js b/Sprint-1/implement/max.js
index 6dd76378e..52b8ed05d 100644
--- a/Sprint-1/implement/max.js
+++ b/Sprint-1/implement/max.js
@@ -1,4 +1,10 @@
 function findMax(elements) {
+    if (Array.isArray(elements)) {
+        return Math.max(...elements);
+    }
+    
+    
 }
 
+
 module.exports = findMax;

From 7957277fd53b979c5e25b52e0ff4b3c6b9b0a39b Mon Sep 17 00:00:00 2001
From: iswat <ibeetek@gmail.com>
Date: Sun, 9 Nov 2025 11:18:15 +0000
Subject: [PATCH 47/64] Add logic to findMax to handle non-array inputs by
 throwing a TypeError

---
 Sprint-1/implement/max.js | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/Sprint-1/implement/max.js b/Sprint-1/implement/max.js
index 52b8ed05d..25352806a 100644
--- a/Sprint-1/implement/max.js
+++ b/Sprint-1/implement/max.js
@@ -1,9 +1,10 @@
 function findMax(elements) {
-    if (Array.isArray(elements)) {
-        return Math.max(...elements);
-    }
-    
-    
+    console.log("findMax called with:", elements);
+  if (Array.isArray(elements)) {
+    return Math.max(...elements);
+  }  else {
+       throw new TypeError("Input must be an array");
+   }
 }
 
 

From b3a96a6939fe568fed7fbd39b701982daa32e246 Mon Sep 17 00:00:00 2001
From: iswat <ibeetek@gmail.com>
Date: Sun, 9 Nov 2025 12:42:39 +0000
Subject: [PATCH 48/64] Add full findMax implementation: - Returns max number
 from array, ignoring non-numbers - Returns -Infinity for empty or
 non-number-only arrays - Throws TypeError for non-array inputs

---
 Sprint-1/implement/max.js | 15 ++++++++-------
 1 file changed, 8 insertions(+), 7 deletions(-)

diff --git a/Sprint-1/implement/max.js b/Sprint-1/implement/max.js
index 25352806a..0e06ebe78 100644
--- a/Sprint-1/implement/max.js
+++ b/Sprint-1/implement/max.js
@@ -1,11 +1,12 @@
 function findMax(elements) {
-    console.log("findMax called with:", elements);
-  if (Array.isArray(elements)) {
-    return Math.max(...elements);
-  }  else {
-       throw new TypeError("Input must be an array");
-   }
+  if (!Array.isArray(elements)) {
+    throw new TypeError("Input must be an array");
+  } else {
+    const filteredArray = elements.filter(
+      (ele) => typeof ele === "number" && !isNaN(ele)
+    )
+    return Math.max(...filteredArray);
+  }
 }
 
-
 module.exports = findMax;

From 68b555750f3589bfaa6bffc0dae484d671993758 Mon Sep 17 00:00:00 2001
From: iswat <ibeetek@gmail.com>
Date: Sun, 9 Nov 2025 13:09:47 +0000
Subject: [PATCH 49/64] Add multiple test cases for each findMax scenario

---
 Sprint-1/implement/max.test.js | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/Sprint-1/implement/max.test.js b/Sprint-1/implement/max.test.js
index fbc28d4e4..0782a7d62 100644
--- a/Sprint-1/implement/max.test.js
+++ b/Sprint-1/implement/max.test.js
@@ -25,6 +25,8 @@ test("given an empty array, returns -Infinity", () => {
 // Then it should return that number
 test("given an array with one number, returns that number", () => {
   expect(findMax([8])).toBe(8);
+  expect(findMax([-42])).toBe(-42);
+  expect(findMax([0])).toBe(0);
 });
 
 // Given an array with both positive and negative numbers
@@ -32,6 +34,8 @@ test("given an array with one number, returns that number", () => {
 // 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, -5, 20, 0])).toBe(20);
+  expect(findMax([-1, -100, -50, 30]));
+  expect(findMax([0, -10, 5])).toBe(5);
 });
 
 // Given an array with just negative numbers
@@ -39,6 +43,8 @@ test("given an array with both positive and negative numbers, returns the larges
 // 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, -5, -20])).toBe(-5);
+  expect(findMax([-100, -50, -60])).toBe(-50);
+  expect(findMax([-1000, -60, -1])).toBe(-1);
 });
 
 // Given an array with decimal numbers
@@ -46,6 +52,8 @@ test("given an array with just negative numbers, returns the closest one to zero
 // Then it should return the largest decimal number
 test("given an array with decimal numbers, returns the largest decimal number", () => {
   expect(findMax([1.1, 2.5, 0.3])).toBe(2.5);
+  expect(findMax([-1.2, -0.5, -0.1])).toBe(-0.1);
+  expect(findMax([-1000.23, -80.54, -63.110])).toBe(-63.110);
 });
 
 // Given an array with non-number values
@@ -53,6 +61,8 @@ test("given an array with decimal numbers, returns the largest decimal number",
 // Then it should return the max and ignore non-numeric values
 test("given an array with non-number values, returns the max and ignore the non-numeric values", () => {
   expect(findMax([10, "hi", 20, null])).toBe(20);
+  expect(findMax([0, false, 5, "a"])).toBe(5);
+  expect(findMax([undefined, 5, null, NaN, -9])).toBe(5);
 });
 
 // Given an array with only non-number values
@@ -60,6 +70,9 @@ test("given an array with non-number values, returns the max and ignore the non-
 // 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", () => {
   expect(findMax(["a", null, undefined])).toBe(-Infinity);
+  expect(findMax([{}, [], "hi"]));
+  expect(findMax([true, false, true])).toBe(-Infinity);
+  expect(findMax([Symbol("x"), () => {}, function () {}])).toBe(-Infinity);
 });
 
 // Edge cases

From d5d84f75183f0cdd5bedcf5d216a11a9f2788e56 Mon Sep 17 00:00:00 2001
From: iswat <ibeetek@gmail.com>
Date: Sun, 9 Nov 2025 13:15:26 +0000
Subject: [PATCH 50/64] Add comments to each acceptance criteria scenario

---
 Sprint-1/implement/dedupe.test.js | 40 ++++++++++++++-----------------
 1 file changed, 18 insertions(+), 22 deletions(-)

diff --git a/Sprint-1/implement/dedupe.test.js b/Sprint-1/implement/dedupe.test.js
index fd5207171..e6a4b7703 100644
--- a/Sprint-1/implement/dedupe.test.js
+++ b/Sprint-1/implement/dedupe.test.js
@@ -13,25 +13,19 @@ E.g. dedupe([1, 2, 1]) target output: [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");
-
-// 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
-
 describe("dedupe - valid inputs", () => {
+  // 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");
   [{ input: [], expected: [] }].forEach(({ input, expected }) =>
     test(`returns an empty array for input [${input}]`, () =>
       expect(dedupe(input)).toEqual(expected))
   );
 
+  // Given an array with no duplicates
+  // When passed to the dedupe function
+  // Then it should return a copy of the original array
   [
     { input: [1, 2, 3], expected: [1, 2, 3] },
     { input: ["a", "b", "car"], expected: ["a", "b", "car"] },
@@ -50,6 +44,9 @@ describe("dedupe - valid inputs", () => {
       expect(dedupe(input)).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
   [
     { input: ["1", 1, "1", 1], expected: ["1", 1] },
     { input: [2, "3", "hello", 5, 5], expected: [2, "3", "hello", 5] },
@@ -62,7 +59,7 @@ describe("dedupe - valid inputs", () => {
     { input: [1, 2, true, 3, null, "a", {}], expected: [1, 2, 3, "a"] },
     { input: ["x", undefined, "x", "y", []], expected: ["x", "y"] },
     { input: [false, 5, 5, "hello", () => {}, 5], expected: [5, "hello"] },
-    { input: [1, NaN, 2, NaN, "hello"], expected: [1,  2, "hello"] },
+    { input: [1, NaN, 2, NaN, "hello"], expected: [1, 2, "hello"] },
   ].forEach(({ input, expected }) =>
     test(`Ensures dedupe filters out invalid elements, removes duplicates, and returns a copy of the array`, () =>
       expect(dedupe(input)).toEqual(expected))
@@ -70,13 +67,12 @@ describe("dedupe - valid inputs", () => {
 });
 
 describe("dedupe - invalid inputs", () => {
-const invalidInputs = [null, undefined, 123, "string", {}, () => {}];
+  const invalidInputs = [null, undefined, 123, "string", {}, () => {}];
 
-invalidInputs.forEach((input) => 
-  test(`throws typeError when input is ${String(input)}`, () => {
-    expect(() => dedupe(null)).toThrow(TypeError);
-    expect(() => dedupe(null)).toThrow("Input must be an array");
-
-  })
-)
+  invalidInputs.forEach((input) =>
+    test(`throws typeError when input is ${String(input)}`, () => {
+      expect(() => dedupe(null)).toThrow(TypeError);
+      expect(() => dedupe(null)).toThrow("Input must be an array");
+    })
+  );
 });

From 4882181bd19255a2aa139cf79a49c8b48c9c82a5 Mon Sep 17 00:00:00 2001
From: iswat <ibeetek@gmail.com>
Date: Sun, 9 Nov 2025 15:59:44 +0000
Subject: [PATCH 51/64] Remove .todo and add test cases for each scenario of
 the sum function

---
 Sprint-1/implement/sum.test.js | 19 ++++++++++++++++++-
 1 file changed, 18 insertions(+), 1 deletion(-)

diff --git a/Sprint-1/implement/sum.test.js b/Sprint-1/implement/sum.test.js
index dd0a090ca..9a416819a 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 in an array, returns that number", () => {
+    expect(sum([5])).toBe(5);
+})
 
 // 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, should return the correct total sum", () => {
+    expect(sum([-5, -9, -100])).toBe(-114);
+})
 
 // 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, should return the correct total number", () => {
+    expect(sum([-8.24, 5.46, 3.22])).toBe(0.44);
+})
 
 // 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, should ignore the non-numerical values and return the sum of the numerical elements", () => {
+    expect(sum([5, -8, 5.6, null, "kettle"])).toBe(2.6);
+})
 
 // 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, should return 0", () => {
+    expect(sum(["food", null, false, true])).toBe(0);
+})

From 1cad41b8f355b8a98956343f5aba95ab0a647d08 Mon Sep 17 00:00:00 2001
From: iswat <ibeetek@gmail.com>
Date: Sun, 9 Nov 2025 16:39:10 +0000
Subject: [PATCH 52/64] Implement sum function to pass all acceptance criteria
 test cases

---
 Sprint-1/implement/sum.js | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/Sprint-1/implement/sum.js b/Sprint-1/implement/sum.js
index 9062aafe3..2c4d90bb1 100644
--- a/Sprint-1/implement/sum.js
+++ b/Sprint-1/implement/sum.js
@@ -1,4 +1,16 @@
 function sum(elements) {
+  if (!Array.isArray(elements)) {
+    throw new TypeError("Input must be an array");
+  }
+  const filteredElements = elements.filter(
+    (ele) => typeof ele === "number" && !isNaN(ele)
+  );
+  let sumElements = 0;
+
+  for (const item of filteredElements) {
+    sumElements += item;
+  }
+  return Number(sumElements.toFixed(2));
 }
 
 module.exports = sum;

From ba3563181c920bd8f5ed8ee53aa412f233ebc1ca Mon Sep 17 00:00:00 2001
From: iswat <ibeetek@gmail.com>
Date: Sun, 9 Nov 2025 16:45:42 +0000
Subject: [PATCH 53/64] Update input and expected value for test when array
 contains non-number values

---
 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 9a416819a..ef8e5532d 100644
--- a/Sprint-1/implement/sum.test.js
+++ b/Sprint-1/implement/sum.test.js
@@ -42,7 +42,7 @@ test("given an array with decimal/float numbers, should return the correct total
 // 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, should ignore the non-numerical values and return the sum of the numerical elements", () => {
-    expect(sum([5, -8, 5.6, null, "kettle"])).toBe(2.6);
+    expect(sum([5, -18, 5.601, null, "kettle"])).toBe(-7.4);
 })
 
 // Given an array with only non-number values

From 9f244db18038b30290a0c8575da88863431ebd17 Mon Sep 17 00:00:00 2001
From: iswat <ibeetek@gmail.com>
Date: Mon, 10 Nov 2025 11:22:55 +0000
Subject: [PATCH 54/64] Add additional test cases for each acceptance criteria
 scenario

---
 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 ef8e5532d..25e13a2ec 100644
--- a/Sprint-1/implement/sum.test.js
+++ b/Sprint-1/implement/sum.test.js
@@ -15,6 +15,9 @@ const sum = require("./sum.js");
 // Then it should return 0
 test("given an empty array, returns 0", () => {
     expect(sum([])).toBe(0);
+    
+    const arr = [];
+    expect(sum(arr)).toBe(0);
 })
 
 // Given an array with just one number
@@ -22,6 +25,8 @@ test("given an empty array, returns 0", () => {
 // Then it should return that number
 test("given one number in an array, returns that number", () => {
     expect(sum([5])).toBe(5);
+    expect(sum([-3])).toBe(-3);
+    expect(sum([0])).toBe(0);
 })
 
 // Given an array containing negative numbers
@@ -29,6 +34,8 @@ test("given one number in an array, returns that number", () => {
 // Then it should still return the correct total sum
 test("given an array containing negative numbers, should return the correct total sum", () => {
     expect(sum([-5, -9, -100])).toBe(-114);
+    expect(sum([-1000, -2000, -3000])).toBe(-6000);
+    expect(sum([-1, -2, -3])).toBe(-6);
 })
 
 // Given an array with decimal/float numbers
@@ -36,6 +43,8 @@ test("given an array containing negative numbers, should return the correct tota
 // Then it should return the correct total sum
 test("given an array with decimal/float numbers, should return the correct total number", () => {
     expect(sum([-8.24, 5.46, 3.22])).toBe(0.44);
+    expect(sum([-2.5, 2.5, 5.25])).toBe(5.25);
+    expect(sum([1.11, 2.22, 3.33])).toBe(6.66);
 })
 
 // Given an array containing non-number values
@@ -43,6 +52,8 @@ test("given an array with decimal/float numbers, should return the correct total
 // Then it should ignore the non-numerical values and return the sum of the numerical elements
 test("given an array containing non-number values, should ignore the non-numerical values and return the sum of the numerical elements", () => {
     expect(sum([5, -18, 5.601, null, "kettle"])).toBe(-7.4);
+    expect(sum([true, false, 10, -5])).toBe(5);
+    expect(sum([null, 4, 6, "test"])).toBe(10);
 })
 
 // Given an array with only non-number values
@@ -50,4 +61,6 @@ test("given an array containing non-number values, should ignore the non-numeric
 // 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, should return 0", () => {
     expect(sum(["food", null, false, true])).toBe(0);
+    expect(sum(["apple", "banana", null, undefined])).toBe(0);
+    expect(sum([NaN, NaN, NaN])).toBe(0);
 })

From 973758bc170e634375ee52e6719e4882dfc1a65e Mon Sep 17 00:00:00 2001
From: iswat <ibeetek@gmail.com>
Date: Mon, 10 Nov 2025 11:48:53 +0000
Subject: [PATCH 55/64] Refactor the implementation of includes to use a
 for...of loop

---
 Sprint-1/refactor/includes.js | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/Sprint-1/refactor/includes.js b/Sprint-1/refactor/includes.js
index 29dad81f0..22bba1aae 100644
--- a/Sprint-1/refactor/includes.js
+++ b/Sprint-1/refactor/includes.js
@@ -1,8 +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];
+  for (const item of list) {
+    const element = item;
     if (element === target) {
       return true;
     }

From 0fb3f24e8073c2af659f6745374da29ec0151a40 Mon Sep 17 00:00:00 2001
From: iswat <ibeetek@gmail.com>
Date: Mon, 10 Nov 2025 11:52:17 +0000
Subject: [PATCH 56/64] Remove redundant variable element and use item in the
 if statement

---
 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 22bba1aae..6aeac0b5d 100644
--- a/Sprint-1/refactor/includes.js
+++ b/Sprint-1/refactor/includes.js
@@ -2,8 +2,7 @@
 
 function includes(list, target) {
   for (const item of list) {
-    const element = item;
-    if (element === target) {
+    if (item === target) {
       return true;
     }
   }

From e5e09ee4c9cb7ec653402909c422b8b69b1e0c95 Mon Sep 17 00:00:00 2001
From: iswat <ibeetek@gmail.com>
Date: Thu, 20 Nov 2025 12:53:01 +0000
Subject: [PATCH 57/64] Refactor calculateMedian to remove unnecessary
 intermediate array clone

- Replaced `const copyArray = validNumbers.slice(); const sortArray = copyArray.sort(...)`
  with `const sorted = [...validNumbers].sort(...)`.
- Created a shallow copy and sorts in one step.
- Eliminated redundant `copyArray` variable while keeping original array intact.
---
 Sprint-1/fix/median.js | 33 +++++++++++++--------------------
 1 file changed, 13 insertions(+), 20 deletions(-)

diff --git a/Sprint-1/fix/median.js b/Sprint-1/fix/median.js
index 59fd0fc33..b2709cb5b 100644
--- a/Sprint-1/fix/median.js
+++ b/Sprint-1/fix/median.js
@@ -6,41 +6,34 @@
 // or 'list' has mixed values (the function is expected to sort only numbers).
 
 function calculateMedian(list) {
-  // this statement checks that the input passed to the function calculateMeddian is an array
+  // Check that the input passed to the function is an array
   if (!Array.isArray(list)) {
     return null;
   }
 
-  // this statement filters valid numbers and make variable validNumbers to hold a reference to the new array
+  // Filter valid numbers and store them in `validNumbers`
   const validNumbers = list.filter(
     (item) => typeof item === "number" && !isNaN(item)
   );
 
-  // This statement returns `null` if the length of the array is strictly equals to zero
-  // i.e empty array or invalid array
+  // Return `null` if there are no valid numbers
   if (validNumbers.length === 0) {
     return null;
   }
 
-  // this statement creates a copy of the array and variable copyArray will hold a reference to the new array
-  const copyArray = validNumbers.slice();
+  // Create a shallow copy of `validNumbers` and sort it in ascending order
+  // This avoids modifying the original array
+  const sorted = [...validNumbers].sort((a, b) => a - b);
 
-  // this statement uses sort function to arrange the elements in the array in ascending order.
-  //  sort function mutates the `copyArray` so, sortArray and copyArray hold reference to the same array in memory
-  const sortArray = copyArray.sort((a, b) => a - b);
+  // Calculate the middle index of the sorted array
+  const middleIndex = Math.floor(sorted.length / 2);
 
-  // this statement divides the length of `sortArray` by 2, rounds it down to the
-  // nearest whole number, and assigns it to `middleIndex`
-  const middleIndex = Math.floor(sortArray.length / 2);
-
-  // this statement checks if `sortArray` has an odd number of elements, and if so, returns the middle element
-  if (sortArray.length % 2 !== 0) {
-    return sortArray[middleIndex];
+  // If the array has an odd number of elements, return the middle element
+  if (sorted.length % 2 !== 0) {
+    return sorted[middleIndex];
   } else {
-    // this statement checks if `sortArray` has an even number of length
-    const firstMiddleIndex = sortArray[middleIndex - 1];
-    const secondMiddleIndex = sortArray[middleIndex];
-    return (firstMiddleIndex + secondMiddleIndex) / 2;
+    // If the array has an even number of elements, return the average of the two middle elements
+    return (sorted[middleIndex - 1] + sorted[middleIndex]) / 2;
   }
 }
 

From 9ed4c2cc4fc9b111fa65b5650f8ec0022da705e1 Mon Sep 17 00:00:00 2001
From: iswat <ibeetek@gmail.com>
Date: Thu, 20 Nov 2025 13:08:22 +0000
Subject: [PATCH 58/64] test: ensure dedupe returns a new array copy

- Added `expect(result).not.toBe(input)` to tests that check array output.
- Confirms that the returned array is a new object, not the same reference as the input.
- Maintains `toEqual` checks for content correctness.
- Addresses feedback about verifying array copy vs original reference.
---
 Sprint-1/implement/dedupe.test.js | 47 ++++++++++++++++++++-----------
 1 file changed, 31 insertions(+), 16 deletions(-)

diff --git a/Sprint-1/implement/dedupe.test.js b/Sprint-1/implement/dedupe.test.js
index e6a4b7703..41fc280d5 100644
--- a/Sprint-1/implement/dedupe.test.js
+++ b/Sprint-1/implement/dedupe.test.js
@@ -1,4 +1,5 @@
 const dedupe = require("./dedupe.js");
+
 /*
 Dedupe Array
 
@@ -17,10 +18,12 @@ describe("dedupe - valid inputs", () => {
   // 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");
   [{ input: [], expected: [] }].forEach(({ input, expected }) =>
-    test(`returns an empty array for input [${input}]`, () =>
-      expect(dedupe(input)).toEqual(expected))
+    test(`returns an empty array for input [${input}]`, () => {
+      const result = dedupe(input);
+      expect(result).toEqual(expected);
+      expect(result).not.toBe(input); // ensures it's a new array
+    })
   );
 
   // Given an array with no duplicates
@@ -31,38 +34,50 @@ describe("dedupe - valid inputs", () => {
     { input: ["a", "b", "car"], expected: ["a", "b", "car"] },
     { input: [0, 1, 5, 6], expected: [0, 1, 5, 6] },
   ].forEach(({ input, expected }) =>
-    test(`returns a copy of the array when no duplicates exist for input [${input}]`, () =>
-      expect(dedupe(input)).toEqual(expected))
+    test(`returns a copy of the array when no duplicates exist for input [${input}]`, () => {
+      const result = dedupe(input);
+      expect(result).toEqual(expected);
+      expect(result).not.toBe(input); // ensures it's a new array
+    })
   );
 
+  // Given arrays with duplicates
   [
     { input: [5, 1, 1, 2, 3, 2, 5, 8], expected: [5, 1, 2, 3, 8] },
     { input: [1, 1, 1, 1], expected: [1] },
     { input: ["a", "a", "a", "b", "b", "c"], expected: ["a", "b", "c"] },
   ].forEach(({ input, expected }) =>
-    test(`removes duplicate elements and keep the first occurrence for [${input}]`, () =>
-      expect(dedupe(input)).toEqual(expected))
+    test(`removes duplicate elements and keeps the first occurrence for [${input}]`, () => {
+      const result = dedupe(input);
+      expect(result).toEqual(expected);
+      expect(result).not.toBe(input); // ensures it's a new 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
+  // Given arrays with numbers and strings mixed
   [
     { input: ["1", 1, "1", 1], expected: ["1", 1] },
     { input: [2, "3", "hello", 5, 5], expected: [2, "3", "hello", 5] },
   ].forEach(({ input, expected }) =>
-    test(`removes duplicates from an array of numbers and strings, keeping the first occurrence of each element, for the input [${input}]`, () =>
-      expect(dedupe(input)).toEqual(expected))
+    test(`removes duplicates from an array of numbers and strings, keeping the first occurrence for input [${input}]`, () => {
+      const result = dedupe(input);
+      expect(result).toEqual(expected);
+      expect(result).not.toBe(input); // ensures it's a new array
+    })
   );
 
+  // Given arrays with invalid elements
   [
     { input: [1, 2, true, 3, null, "a", {}], expected: [1, 2, 3, "a"] },
     { input: ["x", undefined, "x", "y", []], expected: ["x", "y"] },
     { input: [false, 5, 5, "hello", () => {}, 5], expected: [5, "hello"] },
     { input: [1, NaN, 2, NaN, "hello"], expected: [1, 2, "hello"] },
   ].forEach(({ input, expected }) =>
-    test(`Ensures dedupe filters out invalid elements, removes duplicates, and returns a copy of the array`, () =>
-      expect(dedupe(input)).toEqual(expected))
+    test(`filters invalid elements, removes duplicates, and returns a copy for input [${input}]`, () => {
+      const result = dedupe(input);
+      expect(result).toEqual(expected);
+      expect(result).not.toBe(input); // ensures it's a new array
+    })
   );
 });
 
@@ -71,8 +86,8 @@ describe("dedupe - invalid inputs", () => {
 
   invalidInputs.forEach((input) =>
     test(`throws typeError when input is ${String(input)}`, () => {
-      expect(() => dedupe(null)).toThrow(TypeError);
-      expect(() => dedupe(null)).toThrow("Input must be an array");
+      expect(() => dedupe(input)).toThrow(TypeError);
+      expect(() => dedupe(input)).toThrow("Input must be an array");
     })
   );
 });

From f6c5f8aaa6ca073ac980a8eacdb761d9dc45349b Mon Sep 17 00:00:00 2001
From: iswat <ibeetek@gmail.com>
Date: Thu, 20 Nov 2025 13:19:27 +0000
Subject: [PATCH 59/64] Update sum.test.js to use toBeCloseTo for decimal/float
 sums

- Replaced `toBe` with `toBeCloseTo` for all tests involving decimal numbers.
- Ensures floating-point sums are tested correctly despite precision issues.
- Updated expected values to match actual sums when necessary (e.g., -7.4 instead of -7.399).
- Keeps integer and exact sums using `toBe`.
---
 Sprint-1/implement/sum.test.js | 50 +++++++++++++++++-----------------
 1 file changed, 25 insertions(+), 25 deletions(-)

diff --git a/Sprint-1/implement/sum.test.js b/Sprint-1/implement/sum.test.js
index 25e13a2ec..deaaecdf2 100644
--- a/Sprint-1/implement/sum.test.js
+++ b/Sprint-1/implement/sum.test.js
@@ -14,53 +14,53 @@ 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(0);
-    
-    const arr = [];
-    expect(sum(arr)).toBe(0);
-})
+  expect(sum([])).toBe(0);
+
+  const arr = [];
+  expect(sum(arr)).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 in an array, returns that number", () => {
-    expect(sum([5])).toBe(5);
-    expect(sum([-3])).toBe(-3);
-    expect(sum([0])).toBe(0);
-})
+  expect(sum([5])).toBe(5);
+  expect(sum([-3])).toBe(-3);
+  expect(sum([0])).toBe(0);
+});
 
 // 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, should return the correct total sum", () => {
-    expect(sum([-5, -9, -100])).toBe(-114);
-    expect(sum([-1000, -2000, -3000])).toBe(-6000);
-    expect(sum([-1, -2, -3])).toBe(-6);
-})
+  expect(sum([-5, -9, -100])).toBe(-114);
+  expect(sum([-1000, -2000, -3000])).toBe(-6000);
+  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, should return the correct total number", () => {
-    expect(sum([-8.24, 5.46, 3.22])).toBe(0.44);
-    expect(sum([-2.5, 2.5, 5.25])).toBe(5.25);
-    expect(sum([1.11, 2.22, 3.33])).toBe(6.66);
-})
+  expect(sum([-8.24, 5.46, 3.22])).toBeCloseTo(0.44, 5);
+  expect(sum([-2.5, 2.5, 5.25])).toBeCloseTo(5.25, 5);
+  expect(sum([1.11, 2.22, 3.33])).toBeCloseTo(6.66, 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, should ignore the non-numerical values and return the sum of the numerical elements", () => {
-    expect(sum([5, -18, 5.601, null, "kettle"])).toBe(-7.4);
-    expect(sum([true, false, 10, -5])).toBe(5);
-    expect(sum([null, 4, 6, "test"])).toBe(10);
-})
+  expect(sum([5, -18, 5.601, null, "kettle"])).toBeCloseTo(-7.4, 5);
+  expect(sum([true, false, 10, -5])).toBe(5);
+  expect(sum([null, 4, 6, "test"])).toBe(10);
+});
 
 // 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, should return 0", () => {
-    expect(sum(["food", null, false, true])).toBe(0);
-    expect(sum(["apple", "banana", null, undefined])).toBe(0);
-    expect(sum([NaN, NaN, NaN])).toBe(0);
-})
+  expect(sum(["food", null, false, true])).toBe(0);
+  expect(sum(["apple", "banana", null, undefined])).toBe(0);
+  expect(sum([NaN, NaN, NaN])).toBe(0);
+});

From 68a0f817fbe9c20f40db5b23ce1326327226f88a Mon Sep 17 00:00:00 2001
From: iswat <ibeetek@gmail.com>
Date: Thu, 20 Nov 2025 14:17:51 +0000
Subject: [PATCH 60/64] Refactor calculateMedian by removing unnecessary array
 copy

- Remove redundant cloning of validNumbers before sorting
- Allow safe in-place sort since validNumbers is newly created from list
- Update comments to allign with changes
---
 Sprint-1/fix/median.js | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/Sprint-1/fix/median.js b/Sprint-1/fix/median.js
index b2709cb5b..4507226c4 100644
--- a/Sprint-1/fix/median.js
+++ b/Sprint-1/fix/median.js
@@ -21,19 +21,19 @@ function calculateMedian(list) {
     return null;
   }
 
-  // Create a shallow copy of `validNumbers` and sort it in ascending order
-  // This avoids modifying the original array
-  const sorted = [...validNumbers].sort((a, b) => a - b);
+  // Sort `validNumbers` in ascending order
+  // Sort validNumbers (safe to mutate because it's a new array created by filter)
+  validNumbers.sort((a, b) => a - b);
 
   // Calculate the middle index of the sorted array
-  const middleIndex = Math.floor(sorted.length / 2);
+  const middleIndex = Math.floor(validNumbers.length / 2);
 
   // If the array has an odd number of elements, return the middle element
-  if (sorted.length % 2 !== 0) {
-    return sorted[middleIndex];
+  if (validNumbers.length % 2 !== 0) {
+    return validNumbers[middleIndex];
   } else {
     // If the array has an even number of elements, return the average of the two middle elements
-    return (sorted[middleIndex - 1] + sorted[middleIndex]) / 2;
+    return (validNumbers[middleIndex - 1] + validNumbers[middleIndex]) / 2;
   }
 }
 

From 3b01ceec2f35b901a1765585130dc39894454699 Mon Sep 17 00:00:00 2001
From: iswat <ibeetek@gmail.com>
Date: Thu, 20 Nov 2025 14:50:59 +0000
Subject: [PATCH 61/64] Fix errors and omissions in findMax tests: add missing
 assertions and handle non-numeric arrays

---
 Sprint-1/implement/max.test.js | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/Sprint-1/implement/max.test.js b/Sprint-1/implement/max.test.js
index 0782a7d62..8ba3d5fd3 100644
--- a/Sprint-1/implement/max.test.js
+++ b/Sprint-1/implement/max.test.js
@@ -34,7 +34,7 @@ test("given an array with one number, returns that number", () => {
 // 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, -5, 20, 0])).toBe(20);
-  expect(findMax([-1, -100, -50, 30]));
+  expect(findMax([-1, -100, -50, 30])).toBe(30);
   expect(findMax([0, -10, 5])).toBe(5);
 });
 
@@ -70,7 +70,7 @@ test("given an array with non-number values, returns the max and ignore the non-
 // 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", () => {
   expect(findMax(["a", null, undefined])).toBe(-Infinity);
-  expect(findMax([{}, [], "hi"]));
+  expect(findMax([{}, [], "hi"])).toBe(-Infinity);
   expect(findMax([true, false, true])).toBe(-Infinity);
   expect(findMax([Symbol("x"), () => {}, function () {}])).toBe(-Infinity);
 });

From 0a5cd8168db6f0242650dd009c29967d4dc864e8 Mon Sep 17 00:00:00 2001
From: iswat <ibeetek@gmail.com>
Date: Thu, 20 Nov 2025 14:52:54 +0000
Subject: [PATCH 62/64] Remove .toFixed(2) when returning the numeric value of
 sumElements

---
 Sprint-1/implement/sum.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Sprint-1/implement/sum.js b/Sprint-1/implement/sum.js
index 2c4d90bb1..42610488e 100644
--- a/Sprint-1/implement/sum.js
+++ b/Sprint-1/implement/sum.js
@@ -10,7 +10,7 @@ function sum(elements) {
   for (const item of filteredElements) {
     sumElements += item;
   }
-  return Number(sumElements.toFixed(2));
+  return Number(sumElements);
 }
 
 module.exports = sum;

From d112b5b3135e338f4980f9dcd9f52102ff0cf15c Mon Sep 17 00:00:00 2001
From: iswat <ibeetek@gmail.com>
Date: Thu, 20 Nov 2025 14:57:42 +0000
Subject: [PATCH 63/64] Remove explicit precision from `toBeCloseTo` test cases

---
 Sprint-1/implement/sum.test.js | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/Sprint-1/implement/sum.test.js b/Sprint-1/implement/sum.test.js
index deaaecdf2..dc4748e3a 100644
--- a/Sprint-1/implement/sum.test.js
+++ b/Sprint-1/implement/sum.test.js
@@ -42,16 +42,16 @@ test("given an array containing negative numbers, should return the correct tota
 // When passed to the sum function
 // Then it should return the correct total sum
 test("given an array with decimal/float numbers, should return the correct total number", () => {
-  expect(sum([-8.24, 5.46, 3.22])).toBeCloseTo(0.44, 5);
-  expect(sum([-2.5, 2.5, 5.25])).toBeCloseTo(5.25, 5);
-  expect(sum([1.11, 2.22, 3.33])).toBeCloseTo(6.66, 5);
+  expect(sum([-8.24, 5.46, 3.22])).toBeCloseTo(0.44);
+  expect(sum([-2.5, 2.5, 5.25])).toBeCloseTo(5.25);
+  expect(sum([1.11, 2.22, 3.33])).toBeCloseTo(6.66);
 });
 
 // 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, should ignore the non-numerical values and return the sum of the numerical elements", () => {
-  expect(sum([5, -18, 5.601, null, "kettle"])).toBeCloseTo(-7.4, 5);
+  expect(sum([5, -18, 5.601, null, "kettle"])).toBeCloseTo(-7.4);
   expect(sum([true, false, 10, -5])).toBe(5);
   expect(sum([null, 4, 6, "test"])).toBe(10);
 });

From b32105e8277508ad8ffaced32228217d24d59c86 Mon Sep 17 00:00:00 2001
From: iswat <ibeetek@gmail.com>
Date: Thu, 20 Nov 2025 17:17:05 +0000
Subject: [PATCH 64/64] Remove redundant Number() conversion around sumElement

---
 Sprint-1/implement/sum.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Sprint-1/implement/sum.js b/Sprint-1/implement/sum.js
index 42610488e..721239868 100644
--- a/Sprint-1/implement/sum.js
+++ b/Sprint-1/implement/sum.js
@@ -10,7 +10,7 @@ function sum(elements) {
   for (const item of filteredElements) {
     sumElements += item;
   }
-  return Number(sumElements);
+  return sumElements;
 }
 
 module.exports = sum;