From 2071acd370db9ea32bb405122ebd6ed379ad8546 Mon Sep 17 00:00:00 2001
From: marscancode <marsadesina@gmail.com>
Date: Tue, 3 Nov 2026 15:50:29 +0000
Subject: [PATCH 01/42] fixed median calculation for odd and even arrays

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

diff --git a/Sprint-1/fix/median.js b/Sprint-1/fix/median.js
index 5c5b796e1..8cef4118e 100644
--- a/Sprint-1/fix/median.js
+++ b/Sprint-1/fix/median.js
@@ -7,8 +7,12 @@
 
 function calculateMedian(list) {
   const middleIndex = Math.floor(list.length / 2);
-  const median = list.splice(middleIndex, 1)[0];
-  return median;
+
+  if (list.length % 2 === 0) {
+    return (list[middleIndex - 1] + list[middleIndex]) / 2;
+  } else {
+    return list[middleIndex];
+  }
 }
 
 module.exports = calculateMedian;

From 19742a76169f307c87cbd74a764edb702e04a41c Mon Sep 17 00:00:00 2001
From: marscancode <marsadesina@gmail.com>
Date: Tue, 3 Nov 2026 16:03:40 +0000
Subject: [PATCH 02/42] Sorted a copy before calculating the median

---
 Sprint-1/fix/median.js | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/Sprint-1/fix/median.js b/Sprint-1/fix/median.js
index 8cef4118e..0f42cb652 100644
--- a/Sprint-1/fix/median.js
+++ b/Sprint-1/fix/median.js
@@ -6,12 +6,14 @@
 // or contains values that aren't numbers (the function is expected to throw - see the tests).
 
 function calculateMedian(list) {
-  const middleIndex = Math.floor(list.length / 2);
+  const sortedList = [...list];
+  sortedList.sort((a, b) => a - b);
+  const middleIndex = Math.floor(sortedList.length / 2);
 
-  if (list.length % 2 === 0) {
-    return (list[middleIndex - 1] + list[middleIndex]) / 2;
+  if (sortedList.length % 2 === 0) {
+    return (sortedList[middleIndex - 1] + sortedList[middleIndex]) / 2;
   } else {
-    return list[middleIndex];
+    return sortedList[middleIndex];
   }
 }
 

From aca8e91ae2ed2b07758ff23092eb7bdf28568689 Mon Sep 17 00:00:00 2001
From: marscancode <marsadesina@gmail.com>
Date: Tue, 3 Nov 2026 16:14:16 +0000
Subject: [PATCH 03/42] Added a check in function to make sure the input is an
 array

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

diff --git a/Sprint-1/fix/median.js b/Sprint-1/fix/median.js
index 0f42cb652..e7b4d4bfb 100644
--- a/Sprint-1/fix/median.js
+++ b/Sprint-1/fix/median.js
@@ -6,6 +6,9 @@
 // or contains values that aren't numbers (the function is expected to throw - see the tests).
 
 function calculateMedian(list) {
+  if (!Array.isArray(list)) {
+    throw new Error("calculateMedian requires an array of numbers");
+  }
   const sortedList = [...list];
   sortedList.sort((a, b) => a - b);
   const middleIndex = Math.floor(sortedList.length / 2);

From 091e875b4420ff26ce9f3fab478191dedee5d824 Mon Sep 17 00:00:00 2001
From: marscancode <marsadesina@gmail.com>
Date: Tue, 3 Nov 2026 16:20:29 +0000
Subject: [PATCH 04/42] Added a a check in function for empty arrays

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

diff --git a/Sprint-1/fix/median.js b/Sprint-1/fix/median.js
index e7b4d4bfb..f0904dc7b 100644
--- a/Sprint-1/fix/median.js
+++ b/Sprint-1/fix/median.js
@@ -9,6 +9,10 @@ function calculateMedian(list) {
   if (!Array.isArray(list)) {
     throw new Error("calculateMedian requires an array of numbers");
   }
+
+  if (list.length === 0) {
+    throw new Error("calculateMedian requires a non-empty array");
+  }
   const sortedList = [...list];
   sortedList.sort((a, b) => a - b);
   const middleIndex = Math.floor(sortedList.length / 2);

From c4d364885ce11ceab58c9c6f584101b02b19a914 Mon Sep 17 00:00:00 2001
From: marscancode <marsadesina@gmail.com>
Date: Tue, 3 Nov 2026 16:44:04 +0000
Subject: [PATCH 05/42] added check in function that the array only contains
 numbers

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

diff --git a/Sprint-1/fix/median.js b/Sprint-1/fix/median.js
index f0904dc7b..8a58f7c90 100644
--- a/Sprint-1/fix/median.js
+++ b/Sprint-1/fix/median.js
@@ -13,6 +13,10 @@ function calculateMedian(list) {
   if (list.length === 0) {
     throw new Error("calculateMedian requires a non-empty array");
   }
+
+  if (!list.every((number) => typeof number === "number")) {
+    throw new Error("calculateMedian requires an array of numbers");
+  }
   const sortedList = [...list];
   sortedList.sort((a, b) => a - b);
   const middleIndex = Math.floor(sortedList.length / 2);

From fc92cc23b44153180ae3757b9c274a5917df6851 Mon Sep 17 00:00:00 2001
From: marscancode <marsadesina@gmail.com>
Date: Tue, 3 Nov 2026 17:42:10 +0000
Subject: [PATCH 06/42] removed duplicate values from arrays

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

diff --git a/Sprint-1/implement/dedupe.js b/Sprint-1/implement/dedupe.js
index 781e8718a..16b3eb20b 100644
--- a/Sprint-1/implement/dedupe.js
+++ b/Sprint-1/implement/dedupe.js
@@ -1 +1,18 @@
-function dedupe() {}
+function dedupe(numbers) {
+  //function starts
+  const uniqueNumbers = [];
+
+  for (let i = 0; i < numbers.length; i++) {
+    // for loop starts
+    const currentValue = numbers[i];
+
+    if (!uniqueNumbers.includes(currentValue)) {
+      // if statement starts
+      uniqueNumbers.push(currentValue);
+    } // if statement ends
+  } // for loop ends
+
+  return uniqueNumbers;
+} //function ends
+
+module.exports = dedupe;

From a0786537ab04c00647b01d18e48469f5fb19138c Mon Sep 17 00:00:00 2001
From: marscancode <marsadesina@gmail.com>
Date: Tue, 3 Nov 2026 18:11:36 +0000
Subject: [PATCH 07/42] added describe median function

---
 Sprint-1/implement/describe-median.js | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/Sprint-1/implement/describe-median.js b/Sprint-1/implement/describe-median.js
index 3381cfc0a..a56e3d7ba 100644
--- a/Sprint-1/implement/describe-median.js
+++ b/Sprint-1/implement/describe-median.js
@@ -1,5 +1,7 @@
 // Don't change this function.
 function calculateMedian(list) {
+
+
   if (!Array.isArray(list)) {
     throw new Error("calculateMedian requires an array of numbers");
   }
@@ -20,6 +22,13 @@ function calculateMedian(list) {
 }
 
 // Implement this function. See describe-median.test.js for the acceptance criteria.
-function describeMedian(list) {}
+function describeMedian(list) { // opens function
+  try { // opens try statement
+    const median = calculateMedian(list);
+    return `The median is ${median}`;
+  } catch (error) { // opens catch 
+    return "Could not calculate a median: " + error.message;
+  }
+} //closes function
 
 module.exports = describeMedian;

From e02094b0af140b22205fe52d77f658d682ec9f29 Mon Sep 17 00:00:00 2001
From: marscancode <marsadesina@gmail.com>
Date: Tue, 3 Nov 2026 21:33:06 +0000
Subject: [PATCH 08/42] Added tests for describeMedian

---
 Sprint-1/implement/describe-median.test.js | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/Sprint-1/implement/describe-median.test.js b/Sprint-1/implement/describe-median.test.js
index e7d18a264..0696112ee 100644
--- a/Sprint-1/implement/describe-median.test.js
+++ b/Sprint-1/implement/describe-median.test.js
@@ -21,12 +21,25 @@ const describeMedian = require("./describe-median.js");
 // When passed to describeMedian
 // Then it should return "The median is " followed by the median
 // Delete this test.todo and replace it with a test.
-test.todo('given [1, 2, 3], returns "The median is 2"');
+test('given [1, 2, 3], returns "The median is 2"', () => {
+  expect(describeMedian([1, 2, 3])).toEqual("The median is 2");
+});
 
 // Given an empty array
 // When passed to describeMedian
 // Then it should return "Could not calculate a median: calculateMedian requires a non-empty array"
+test("given an empty array returns an error message", () => {
+  expect(describeMedian([])).toEqual(
+    "Could not calculate a median: calculateMedian requires a non-empty array"
+  );
+});
 
 // Given something that isn't an array of numbers, e.g. "banana"
 // When passed to describeMedian
 // Then it should return "Could not calculate a median: calculateMedian requires an array of numbers"
+
+test("given a string returns an error message", () => {
+  expect(describeMedian("banana")).toEqual(
+    "Could not calculate a median: calculateMedian requires an array of numbers"
+  );
+});

From 1875b30655d230b2a9423d8a6d863e43d8283442 Mon Sep 17 00:00:00 2001
From: marscancode <marsadesina@gmail.com>
Date: Tue, 3 Nov 2026 21:37:14 +0000
Subject: [PATCH 09/42] Ignore prep directory

---
 .gitignore | 1 +
 1 file changed, 1 insertion(+)

diff --git a/.gitignore b/.gitignore
index 8ee70353f..ac74be127 100644
--- a/.gitignore
+++ b/.gitignore
@@ -4,3 +4,4 @@ node_modules
 **/.DS_Store
 .idea
 package-lock.json
+/prep/

From f9a47c72794684f5172f5b4bbb448d67dbc5d66e Mon Sep 17 00:00:00 2001
From: marscancode <marsadesina@gmail.com>
Date: Tue, 3 Nov 2026 22:20:35 +0000
Subject: [PATCH 10/42] Implemented findMax function

---
 Sprint-1/implement/max.js | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/Sprint-1/implement/max.js b/Sprint-1/implement/max.js
index 6dd76378e..663218659 100644
--- a/Sprint-1/implement/max.js
+++ b/Sprint-1/implement/max.js
@@ -1,4 +1,20 @@
 function findMax(elements) {
+  if (
+    !Array.isArray(elements) ||
+    !elements.every((element) => typeof element === "number")
+  ) {
+    throw new Error("findMax requires an array of numbers");
+  }
+
+  let max = -Infinity;
+
+  for (let i = 0; i < elements.length; i++) {
+    if (elements[i] > max) {
+      max = elements[i];
+    }
+  }
+
+  return max;
 }
 
 module.exports = findMax;

From 1516690d3b716c8eb82eb13a7ebc9e8daad56799 Mon Sep 17 00:00:00 2001
From: marscancode <marsadesina@gmail.com>
Date: Tue, 3 Nov 2026 22:33:53 +0000
Subject: [PATCH 11/42] added empty and single-number tests for findMax

---
 Sprint-1/implement/max.test.js | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/Sprint-1/implement/max.test.js b/Sprint-1/implement/max.test.js
index ff3fbb5e5..137dba18e 100644
--- a/Sprint-1/implement/max.test.js
+++ b/Sprint-1/implement/max.test.js
@@ -16,11 +16,16 @@ 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, should return -Infinity", () => {
+  expect(findMax([])).toEqual(-Infinity);
+});
 
 // Given an array with one number
 // When passed to the max function
 // Then it should return that number
+test("expects findMax with an array containing 7 to return 7", () => {
+  expect(findMax([7])).toEqual(7);
+});
 
 // Given an array with both positive and negative numbers
 // When passed to the max function

From 445b260754f202ca71e64b0e49c83c2da9cf261b Mon Sep 17 00:00:00 2001
From: marscancode <marsadesina@gmail.com>
Date: Tue, 3 Nov 2026 22:44:28 +0000
Subject: [PATCH 12/42] Added test for both positive and negative numbers

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

diff --git a/Sprint-1/implement/max.test.js b/Sprint-1/implement/max.test.js
index 137dba18e..f81eaa5bf 100644
--- a/Sprint-1/implement/max.test.js
+++ b/Sprint-1/implement/max.test.js
@@ -30,7 +30,9 @@ test("expects findMax with an array containing 7 to return 7", () => {
 // Given an array with both positive and negative numbers
 // When passed to the max function
 // Then it should return the largest number overall
-
+test("returns largest number given an array with both positive and negative numbers", () => {
+  expect(findMax([-5, -6, 10, 4])).toEqual(10);
+});
 // Given an array with just negative numbers
 // When passed to the max function
 // Then it should return the closest one to zero

From 4337038728888114455598d8ea359474669b61ea Mon Sep 17 00:00:00 2001
From: marscancode <marsadesina@gmail.com>
Date: Tue, 3 Nov 2026 22:47:38 +0000
Subject: [PATCH 13/42] Add test for array with negative numbers

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

diff --git a/Sprint-1/implement/max.test.js b/Sprint-1/implement/max.test.js
index f81eaa5bf..45d1983a9 100644
--- a/Sprint-1/implement/max.test.js
+++ b/Sprint-1/implement/max.test.js
@@ -36,7 +36,9 @@ test("returns largest number given an array with both positive and negative numb
 // Given an array with just negative numbers
 // When passed to the max function
 // Then it should return the closest one to zero
-
+test("returns largest number when given an array with negative numbers", () => {
+  expect(findMax([-4, -7, -9, -14])).toEqual(-4);
+});
 // Given an array with decimal numbers
 // When passed to the max function
 // Then it should return the largest decimal number

From 6fd0acf23367d7928bf77216d67ee1627c8e0e5c Mon Sep 17 00:00:00 2001
From: marscancode <marsadesina@gmail.com>
Date: Tue, 3 Nov 2026 22:50:39 +0000
Subject: [PATCH 14/42] added test for decimal numbers

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

diff --git a/Sprint-1/implement/max.test.js b/Sprint-1/implement/max.test.js
index 45d1983a9..64050f362 100644
--- a/Sprint-1/implement/max.test.js
+++ b/Sprint-1/implement/max.test.js
@@ -42,7 +42,9 @@ test("returns largest number when given an array with negative numbers", () => {
 // Given an array with decimal numbers
 // When passed to the max function
 // Then it should return the largest decimal number
-
+test("returns largest number when given an array of decimal numbers", () => {
+  expect(findMax([2.2, 4.3, 6.8, 9.4])).toEqual(9.4);
+});
 // Given an array containing a value that isn't a number
 // When passed to the max function
 // Then it should throw Error("findMax requires an array of numbers")

From 8490f09ae2a91bc4e3dd640e5db9e4df70155464 Mon Sep 17 00:00:00 2001
From: marscancode <marsadesina@gmail.com>
Date: Tue, 3 Nov 2026 22:56:40 +0000
Subject: [PATCH 15/42] added test for value that isnt a number

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

diff --git a/Sprint-1/implement/max.test.js b/Sprint-1/implement/max.test.js
index 64050f362..3ee02ba66 100644
--- a/Sprint-1/implement/max.test.js
+++ b/Sprint-1/implement/max.test.js
@@ -48,7 +48,11 @@ test("returns largest number when given an array of decimal numbers", () => {
 // Given an array containing a value that isn't a number
 // When passed to the max function
 // Then it should throw Error("findMax requires an array of numbers")
-
+test("given an array containing a value that isn't a number", () => {
+  expect(() => findMax([4, "hello", 5])).toThrow(
+    "findMax requires an array of numbers"
+  );
+});
 // Given something that isn't an array at all, such as "hey", 42 or no argument
 // When passed to the max function
 // Then it should throw Error("findMax requires an array of numbers")

From 7b42dd0da6343f380f3a5b03bdc0337797ac4601 Mon Sep 17 00:00:00 2001
From: marscancode <marsadesina@gmail.com>
Date: Tue, 3 Nov 2026 23:03:54 +0000
Subject: [PATCH 16/42] Completed findMax tests

---
 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 3ee02ba66..21f25ffe7 100644
--- a/Sprint-1/implement/max.test.js
+++ b/Sprint-1/implement/max.test.js
@@ -56,3 +56,16 @@ test("given an array containing a value that isn't a number", () => {
 // Given something that isn't an array at all, such as "hey", 42 or no argument
 // When passed to the max function
 // Then it should throw Error("findMax requires an array of numbers")
+test("given something that isn't an array at all", () => {
+  expect(() => findMax("hey")).toThrow(
+    "findMax requires an array of numbers"
+  );
+
+  expect(() => findMax(42)).toThrow(
+    "findMax requires an array of numbers"
+  );
+
+  expect(() => findMax()).toThrow(
+    "findMax requires an array of numbers"
+  );
+});
\ No newline at end of file

From 9f17e6dae044e93fce1f963b5a82a234ffa0cd37 Mon Sep 17 00:00:00 2001
From: marscancode <marsadesina@gmail.com>
Date: Wed, 4 Nov 2026 11:41:45 +0000
Subject: [PATCH 17/42] added first test for calculateMean, it fails

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

diff --git a/Sprint-1/implement/mean.test.js b/Sprint-1/implement/mean.test.js
index 847b88676..fbba037ba 100644
--- a/Sprint-1/implement/mean.test.js
+++ b/Sprint-1/implement/mean.test.js
@@ -23,7 +23,9 @@ const calculateMean = require("./mean.js");
 // When passed to calculateMean
 // Then it should return their mean
 // Delete this test.todo and replace it with a test.
-test.todo("given [1, 2, 6], returns 3");
+test("given the array [1,2,6], should return the number 3", () => {
+  expect(calculateMean([1, 2, 6])).toEqual(3);
+});
 
 // Given an array with a single number
 // When passed to calculateMean

From 19d9c71134b99ea51ca10d9ff9764763d03c97f1 Mon Sep 17 00:00:00 2001
From: marscancode <marsadesina@gmail.com>
Date: Wed, 4 Nov 2026 12:16:54 +0000
Subject: [PATCH 18/42] implemented function calculateMean

---
 Sprint-1/implement/mean.js | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/Sprint-1/implement/mean.js b/Sprint-1/implement/mean.js
index 36909ea1f..2490df14c 100644
--- a/Sprint-1/implement/mean.js
+++ b/Sprint-1/implement/mean.js
@@ -1,3 +1,9 @@
-function calculateMean(list) {}
+function calculateMean(list) {
+  const sum = list.reduce((sum, number) => {
+    return sum + number;
+  }, 0);
+
+  return sum / list.length;
+}
 
 module.exports = calculateMean;

From 063182ae15c176726f78c293a71d71950a788197 Mon Sep 17 00:00:00 2001
From: marscancode <marsadesina@gmail.com>
Date: Wed, 4 Nov 2026 14:25:20 +0000
Subject: [PATCH 19/42] test to check wether calculateMean works given an array
 with a single number, it passes

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

diff --git a/Sprint-1/implement/mean.test.js b/Sprint-1/implement/mean.test.js
index fbba037ba..ccbb09751 100644
--- a/Sprint-1/implement/mean.test.js
+++ b/Sprint-1/implement/mean.test.js
@@ -30,6 +30,9 @@ test("given the array [1,2,6], should return the number 3", () => {
 // Given an array with a single number
 // When passed to calculateMean
 // Then it should return that number
+test("given an array with a single number, should return 7", () => {
+  expect(calculateMean([7])).toEqual(7);
+});
 
 // Given an array containing negative or decimal numbers
 // When passed to calculateMean

From 1b1468ed4c74e9c869cce8cf047fbd049df4f9cf Mon Sep 17 00:00:00 2001
From: marscancode <marsadesina@gmail.com>
Date: Wed, 4 Nov 2026 14:30:01 +0000
Subject: [PATCH 20/42] test to check how calculateMean handles an array of
 negative numbers, it passes

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

diff --git a/Sprint-1/implement/mean.test.js b/Sprint-1/implement/mean.test.js
index ccbb09751..4242df813 100644
--- a/Sprint-1/implement/mean.test.js
+++ b/Sprint-1/implement/mean.test.js
@@ -37,7 +37,9 @@ test("given an array with a single number, should return 7", () => {
 // Given an array containing negative or decimal numbers
 // When passed to calculateMean
 // Then it should return the correct mean
-
+test("given an array of negative numbers, should return -4", () => {
+  expect(calculateMean([-2, -4, -6])).toEqual(-4);
+});
 // Given an empty array
 // When passed to calculateMean
 // Then it should throw Error("calculateMean requires a non-empty array")

From d90b2cf5a76807ed2d63ca530080f19f663e186b Mon Sep 17 00:00:00 2001
From: marscancode <marsadesina@gmail.com>
Date: Wed, 4 Nov 2026 14:34:24 +0000
Subject: [PATCH 21/42] test to check wether calculateMean handles an array of
 decimal numbers, it passes

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

diff --git a/Sprint-1/implement/mean.test.js b/Sprint-1/implement/mean.test.js
index 4242df813..e6de86695 100644
--- a/Sprint-1/implement/mean.test.js
+++ b/Sprint-1/implement/mean.test.js
@@ -40,6 +40,9 @@ test("given an array with a single number, should return 7", () => {
 test("given an array of negative numbers, should return -4", () => {
   expect(calculateMean([-2, -4, -6])).toEqual(-4);
 });
+test("given an array of decimal numbers, should return 2.5", () => {
+  expect(calculateMean([1.5, 2.5, 3.5])).toEqual(2.5);
+});
 // Given an empty array
 // When passed to calculateMean
 // Then it should throw Error("calculateMean requires a non-empty array")

From 7547c25742cc0fd3768bfa0925e97750ff72c9e7 Mon Sep 17 00:00:00 2001
From: marscancode <marsadesina@gmail.com>
Date: Wed, 4 Nov 2026 14:45:42 +0000
Subject: [PATCH 22/42] added test to check wether calculateMean throws an
 error when given an empty array, it fails

---
 Sprint-1/implement/mean.test.js | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/Sprint-1/implement/mean.test.js b/Sprint-1/implement/mean.test.js
index e6de86695..b1595a3bc 100644
--- a/Sprint-1/implement/mean.test.js
+++ b/Sprint-1/implement/mean.test.js
@@ -46,7 +46,11 @@ test("given an array of decimal numbers, should return 2.5", () => {
 // Given an empty array
 // When passed to calculateMean
 // Then it should throw Error("calculateMean requires a non-empty array")
-
+test("given an empty array, should throw an error", () => {
+  expect(() => calculateMean([])).toThrow(
+    "calculateMean requires a non-empty array"
+  );
+});
 // Given a value that isn't an array, e.g. "banana", 42, null or {}
 // When passed to calculateMean
 // Then it should throw Error("calculateMean requires an array of numbers")

From c87f412b932bd45e7491538482918534d077a08b Mon Sep 17 00:00:00 2001
From: marscancode <marsadesina@gmail.com>
Date: Wed, 4 Nov 2026 14:52:05 +0000
Subject: [PATCH 23/42] implemented calculateMean to handle empty arrays

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

diff --git a/Sprint-1/implement/mean.js b/Sprint-1/implement/mean.js
index 2490df14c..4dc450b14 100644
--- a/Sprint-1/implement/mean.js
+++ b/Sprint-1/implement/mean.js
@@ -1,4 +1,7 @@
 function calculateMean(list) {
+  if (list.length === 0) {
+    throw new Error("calculateMean requires a non-empty array");
+  }
   const sum = list.reduce((sum, number) => {
     return sum + number;
   }, 0);

From f24628a57218f4437b5fbf564275c10a44b35225 Mon Sep 17 00:00:00 2001
From: marscancode <marsadesina@gmail.com>
Date: Wed, 4 Nov 2026 15:05:23 +0000
Subject: [PATCH 24/42] test to check if calculateMean throws an error when
 given a string instead of an array

---
 Sprint-1/implement/mean.test.js | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/Sprint-1/implement/mean.test.js b/Sprint-1/implement/mean.test.js
index b1595a3bc..a405e28d7 100644
--- a/Sprint-1/implement/mean.test.js
+++ b/Sprint-1/implement/mean.test.js
@@ -54,7 +54,11 @@ test("given an empty array, should throw an error", () => {
 // Given a value that isn't an array, e.g. "banana", 42, null or {}
 // When passed to calculateMean
 // Then it should throw Error("calculateMean requires an array of numbers")
-
+test("given a string instead of an array, should throw an error", () => {
+  expect(() => calculateMean("banana")).toThrow(
+    "calculateMean requires an array of numbers"
+  );
+});
 // Given no argument at all
 // When passed to calculateMean
 // Then it should throw Error("calculateMean requires an array of numbers")

From c5745352bba1624fa6d5a3af9d6035c7f0460de2 Mon Sep 17 00:00:00 2001
From: marscancode <marsadesina@gmail.com>
Date: Wed, 4 Nov 2026 15:12:36 +0000
Subject: [PATCH 25/42] implemented calculateMean to handle a string, tests
 pass

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

diff --git a/Sprint-1/implement/mean.js b/Sprint-1/implement/mean.js
index 4dc450b14..d6cee5447 100644
--- a/Sprint-1/implement/mean.js
+++ b/Sprint-1/implement/mean.js
@@ -1,4 +1,7 @@
 function calculateMean(list) {
+  if (!Array.isArray(list)) {
+    throw new Error("calculateMean requires an array of numbers");
+  }
   if (list.length === 0) {
     throw new Error("calculateMean requires a non-empty array");
   }

From c427aa2e052e6b3358b8f0d0f18179bad427e63b Mon Sep 17 00:00:00 2001
From: marscancode <marsadesina@gmail.com>
Date: Wed, 4 Nov 2026 15:21:17 +0000
Subject: [PATCH 26/42] added tests for calculateMean for invalid non-array
 values

---
 Sprint-1/implement/mean.test.js | 18 +++++++++++++++++-
 1 file changed, 17 insertions(+), 1 deletion(-)

diff --git a/Sprint-1/implement/mean.test.js b/Sprint-1/implement/mean.test.js
index a405e28d7..eae50dce6 100644
--- a/Sprint-1/implement/mean.test.js
+++ b/Sprint-1/implement/mean.test.js
@@ -54,10 +54,26 @@ test("given an empty array, should throw an error", () => {
 // Given a value that isn't an array, e.g. "banana", 42, null or {}
 // When passed to calculateMean
 // Then it should throw Error("calculateMean requires an array of numbers")
-test("given a string instead of an array, should throw an error", () => {
+test("given a value that isn't an array, should throw an error", () => {
   expect(() => calculateMean("banana")).toThrow(
     "calculateMean requires an array of numbers"
   );
+
+  expect(() => calculateMean(42)).toThrow(
+    "calculateMean requires an array of numbers"
+  );
+
+  expect(() => calculateMean(null)).toThrow(
+    "calculateMean requires an array of numbers"
+  );
+
+  expect(() => calculateMean({})).toThrow(
+    "calculateMean requires an array of numbers"
+  );
+
+  expect(() => calculateMean()).toThrow(
+    "calculateMean requires an array of numbers"
+  );
 });
 // Given no argument at all
 // When passed to calculateMean

From 108c621ed048b4fa2512a898eafeca628bdb5ec7 Mon Sep 17 00:00:00 2001
From: marscancode <marsadesina@gmail.com>
Date: Wed, 4 Nov 2026 15:32:14 +0000
Subject: [PATCH 27/42] deleted duplicate empty array test

---
 Sprint-1/implement/mean.test.js | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/Sprint-1/implement/mean.test.js b/Sprint-1/implement/mean.test.js
index eae50dce6..1cb5788c9 100644
--- a/Sprint-1/implement/mean.test.js
+++ b/Sprint-1/implement/mean.test.js
@@ -75,10 +75,6 @@ test("given a value that isn't an array, should throw an error", () => {
     "calculateMean requires an array of numbers"
   );
 });
-// Given no argument at all
-// When passed to calculateMean
-// Then it should throw Error("calculateMean requires an array of numbers")
-
 // Given an array containing a non-number value, e.g. [1, "2", 3]
 // When passed to calculateMean
 // Then it should throw Error("calculateMean requires an array of numbers")

From 03ec9391880688b6ccf1cbb32f75f6fcca3051e8 Mon Sep 17 00:00:00 2001
From: marscancode <marsadesina@gmail.com>
Date: Wed, 4 Nov 2026 15:37:59 +0000
Subject: [PATCH 28/42] added test to check if calculateMedian throws an error
 when given an array with a non-number value

---
 Sprint-1/implement/mean.test.js | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/Sprint-1/implement/mean.test.js b/Sprint-1/implement/mean.test.js
index 1cb5788c9..1b716ae38 100644
--- a/Sprint-1/implement/mean.test.js
+++ b/Sprint-1/implement/mean.test.js
@@ -78,3 +78,8 @@ test("given a value that isn't an array, should throw an error", () => {
 // Given an array containing a non-number value, e.g. [1, "2", 3]
 // When passed to calculateMean
 // Then it should throw Error("calculateMean requires an array of numbers")
+test("given an array containing a non-number value, should throw an error", () => {
+  expect(() => calculateMean([1, "2", 3])).toThrow(
+    "calculateMean requires an array of numbers"
+  );
+});

From 304895230c0ce34ce131536829cb2fba62908f92 Mon Sep 17 00:00:00 2001
From: marscancode <marsadesina@gmail.com>
Date: Wed, 4 Nov 2026 15:45:16 +0000
Subject: [PATCH 29/42] implemented calculate mean to only take in arrays with
 number values

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

diff --git a/Sprint-1/implement/mean.js b/Sprint-1/implement/mean.js
index d6cee5447..f8e710d29 100644
--- a/Sprint-1/implement/mean.js
+++ b/Sprint-1/implement/mean.js
@@ -5,6 +5,9 @@ function calculateMean(list) {
   if (list.length === 0) {
     throw new Error("calculateMean requires a non-empty array");
   }
+  if (!list.every((number) => typeof number === "number")) {
+    throw new Error("calculateMean requires an array of numbers");
+  }
   const sum = list.reduce((sum, number) => {
     return sum + number;
   }, 0);

From e6bec3a36aee120aa061f1149d2defb30db928c2 Mon Sep 17 00:00:00 2001
From: marscancode <marsadesina@gmail.com>
Date: Wed, 4 Nov 2026 15:51:23 +0000
Subject: [PATCH 30/42] added test for empty sum array

---
 Sprint-1/implement/sum.test.js | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/Sprint-1/implement/sum.test.js b/Sprint-1/implement/sum.test.js
index a288e0f0a..40dc16336 100644
--- a/Sprint-1/implement/sum.test.js
+++ b/Sprint-1/implement/sum.test.js
@@ -13,8 +13,9 @@ 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([])).toEqual(0);
+});
 // Given an array with just one number
 // When passed to the sum function
 // Then it should return that number

From 15f68c93ae63e830bbd6179af6a36c67e5dcc095 Mon Sep 17 00:00:00 2001
From: marscancode <marsadesina@gmail.com>
Date: Wed, 4 Nov 2026 16:04:07 +0000
Subject: [PATCH 31/42] implemented the sum function using reduce, test passes

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

diff --git a/Sprint-1/implement/sum.js b/Sprint-1/implement/sum.js
index 9062aafe3..37c2c4ff5 100644
--- a/Sprint-1/implement/sum.js
+++ b/Sprint-1/implement/sum.js
@@ -1,4 +1,7 @@
 function sum(elements) {
+  const sum = elements.reduce((sum, number) => {
+    return number + sum;
+  }, 0);
+  return sum;
 }
-
 module.exports = sum;

From e4a79ce3cf704f2431ce6b6f9cfb0b2becfdfcaf Mon Sep 17 00:00:00 2001
From: marscancode <marsadesina@gmail.com>
Date: Wed, 4 Nov 2026 16:18:58 +0000
Subject: [PATCH 32/42] added test to check if an array with one number returns
 the number

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

diff --git a/Sprint-1/implement/sum.test.js b/Sprint-1/implement/sum.test.js
index 40dc16336..9de668f27 100644
--- a/Sprint-1/implement/sum.test.js
+++ b/Sprint-1/implement/sum.test.js
@@ -19,6 +19,9 @@ test("given an empty array, returns 0", () => {
 // Given an array with just one number
 // When passed to the sum function
 // Then it should return that number
+test("given an array with one number, returns that number", () => {
+  expect(sum([7])).toEqual(7);
+});
 
 // Given an array containing negative numbers
 // When passed to the sum function

From 51a5109a0a88301f2abebcb6ced5624c20c53776 Mon Sep 17 00:00:00 2001
From: marscancode <marsadesina@gmail.com>
Date: Wed, 4 Nov 2026 16:22:38 +0000
Subject: [PATCH 33/42] added test to check if sum can handle negative numbers

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

diff --git a/Sprint-1/implement/sum.test.js b/Sprint-1/implement/sum.test.js
index 9de668f27..30b290b00 100644
--- a/Sprint-1/implement/sum.test.js
+++ b/Sprint-1/implement/sum.test.js
@@ -26,6 +26,9 @@ test("given an array with one number, returns that number", () => {
 // Given an array containing negative numbers
 // When passed to the sum function
 // Then it should still return the correct total sum
+test("given an array with negative numbers, returns the correct sum", () => {
+  expect(sum([-4, -6, -2])).toEqual(-12);
+});
 
 // Given an array with decimal/float numbers
 // When passed to the sum function

From 597c5f560b76ce2a42546e7260e476c0e709c94b Mon Sep 17 00:00:00 2001
From: marscancode <marsadesina@gmail.com>
Date: Wed, 4 Nov 2026 16:27:13 +0000
Subject: [PATCH 34/42] added test for sum with decimal numbers

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

diff --git a/Sprint-1/implement/sum.test.js b/Sprint-1/implement/sum.test.js
index 30b290b00..0f3fd2532 100644
--- a/Sprint-1/implement/sum.test.js
+++ b/Sprint-1/implement/sum.test.js
@@ -33,6 +33,9 @@ test("given an array with negative numbers, returns the correct sum", () => {
 // Given an array with decimal/float numbers
 // When passed to the sum function
 // Then it should return the correct total sum
+test("given an array with decimal numbers, returns the correct sum", () => {
+  expect(sum([2.5, 3.5, 5.5])).toEqual(11.5);
+});
 
 // Given an array containing a value that isn't a number
 // When passed to the sum function

From 28a59d05e03fa5dce2c378d8322c116434d139e8 Mon Sep 17 00:00:00 2001
From: marscancode <marsadesina@gmail.com>
Date: Wed, 4 Nov 2026 16:30:23 +0000
Subject: [PATCH 35/42] added test to check if sum throws an error when given
 an array containing a non-number

---
 Sprint-1/implement/sum.test.js | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/Sprint-1/implement/sum.test.js b/Sprint-1/implement/sum.test.js
index 0f3fd2532..4568f78e7 100644
--- a/Sprint-1/implement/sum.test.js
+++ b/Sprint-1/implement/sum.test.js
@@ -40,7 +40,11 @@ test("given an array with decimal numbers, returns the correct sum", () => {
 // Given an array containing a value that isn't a number
 // When passed to the sum function
 // Then it should throw Error("sum requires an array of numbers")
-
+test("given an array containing a non-number, throws an error", () => {
+  expect(() => sum([10, "hello", 2])).toThrow(
+    "sum requires an array of numbers"
+  );
+});
 // Given something that isn't an array at all, such as "hey", 42 or no argument
 // When passed to the sum function
 // Then it should throw Error("sum requires an array of numbers")

From 4e83c4c483f6c52d3032f99df6d02d4a01c08291 Mon Sep 17 00:00:00 2001
From: marscancode <marsadesina@gmail.com>
Date: Wed, 4 Nov 2026 16:34:14 +0000
Subject: [PATCH 36/42] implemented sum function using reduce

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

diff --git a/Sprint-1/implement/sum.js b/Sprint-1/implement/sum.js
index 37c2c4ff5..1e3465c03 100644
--- a/Sprint-1/implement/sum.js
+++ b/Sprint-1/implement/sum.js
@@ -5,3 +5,4 @@ function sum(elements) {
   return sum;
 }
 module.exports = sum;
+

From c9f77547955ae9c98b4f0a65afb648c03415b296 Mon Sep 17 00:00:00 2001
From: marscancode <marsadesina@gmail.com>
Date: Wed, 4 Nov 2026 16:41:16 +0000
Subject: [PATCH 37/42] implemented sum function to throw an error if given an
 array containing a non-number

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

diff --git a/Sprint-1/implement/sum.js b/Sprint-1/implement/sum.js
index 1e3465c03..70e1b9988 100644
--- a/Sprint-1/implement/sum.js
+++ b/Sprint-1/implement/sum.js
@@ -1,8 +1,10 @@
 function sum(elements) {
+  if (!elements.every((element) => typeof element === "number")) {
+    throw new Error("sum requires an array of numbers");
+  }
   const sum = elements.reduce((sum, number) => {
     return number + sum;
   }, 0);
   return sum;
 }
 module.exports = sum;
-

From 75d26abbda04091d55072313af485cc720dc9f58 Mon Sep 17 00:00:00 2001
From: marscancode <marsadesina@gmail.com>
Date: Wed, 4 Nov 2026 16:47:25 +0000
Subject: [PATCH 38/42] added test for non-array input in sum function

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

diff --git a/Sprint-1/implement/sum.test.js b/Sprint-1/implement/sum.test.js
index 4568f78e7..0378ddcfc 100644
--- a/Sprint-1/implement/sum.test.js
+++ b/Sprint-1/implement/sum.test.js
@@ -48,3 +48,7 @@ test("given an array containing a non-number, throws an error", () => {
 // Given something that isn't an array at all, such as "hey", 42 or no argument
 // When passed to the sum function
 // Then it should throw Error("sum requires an array of numbers")
+
+test("given a non-array input, throws an error", () => {
+  expect(() => sum("hello")).toThrow("sum requires an array of numbers");
+});

From 9abe6cc91a05e5a2a8f45345387c94671ee693a1 Mon Sep 17 00:00:00 2001
From: marscancode <marsadesina@gmail.com>
Date: Wed, 4 Nov 2026 16:52:14 +0000
Subject: [PATCH 39/42] implemented sum function to check array input if
 incorrect throw error

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

diff --git a/Sprint-1/implement/sum.js b/Sprint-1/implement/sum.js
index 70e1b9988..9fde47645 100644
--- a/Sprint-1/implement/sum.js
+++ b/Sprint-1/implement/sum.js
@@ -1,8 +1,11 @@
 function sum(elements) {
+  if (!Array.isArray(elements)) {
+    throw new Error("sum requires an array of numbers");
+  }
   if (!elements.every((element) => typeof element === "number")) {
     throw new Error("sum requires an array of numbers");
   }
-  const sum = elements.reduce((sum, number) => {
+const sum = elements.reduce((sum, number) => {
     return number + sum;
   }, 0);
   return sum;

From 80d443407f0aab7b92a310d1289dfb0802272269 Mon Sep 17 00:00:00 2001
From: marscancode <marsadesina@gmail.com>
Date: Wed, 4 Nov 2026 16:57:08 +0000
Subject: [PATCH 40/42] Add tests for non-array and missing sum arguments

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

diff --git a/Sprint-1/implement/sum.test.js b/Sprint-1/implement/sum.test.js
index 0378ddcfc..4ff06f55f 100644
--- a/Sprint-1/implement/sum.test.js
+++ b/Sprint-1/implement/sum.test.js
@@ -52,3 +52,7 @@ test("given an array containing a non-number, throws an error", () => {
 test("given a non-array input, throws an error", () => {
   expect(() => sum("hello")).toThrow("sum requires an array of numbers");
 });
+
+test("given no argument, throws an error", () => {
+  expect(() => sum()).toThrow("sum requires an array of numbers");
+});

From 9ea7f047bce9b9f8ebd894f0967c331bae9717c1 Mon Sep 17 00:00:00 2001
From: marscancode <marsadesina@gmail.com>
Date: Wed, 4 Nov 2026 16:59:52 +0000
Subject: [PATCH 41/42] added test for number input in sum function

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

diff --git a/Sprint-1/implement/sum.test.js b/Sprint-1/implement/sum.test.js
index 4ff06f55f..94a78e0af 100644
--- a/Sprint-1/implement/sum.test.js
+++ b/Sprint-1/implement/sum.test.js
@@ -56,3 +56,6 @@ test("given a non-array input, throws an error", () => {
 test("given no argument, throws an error", () => {
   expect(() => sum()).toThrow("sum requires an array of numbers");
 });
+test("given a number instead of an array, throws an error", () => {
+  expect(() => sum(42)).toThrow("sum requires an array of numbers");
+});

From 556c1a79d7cec92083d0d2a97ee8808d43ab65a2 Mon Sep 17 00:00:00 2001
From: marscancode <marsadesina@gmail.com>
Date: Thu, 5 Nov 2026 11:27:00 +0000
Subject: [PATCH 42/42] refactored includes to use a for...of loop, tests pass

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

diff --git a/Sprint-1/refactor/includes.js b/Sprint-1/refactor/includes.js
index 29dad81f0..78bbc70b0 100644
--- a/Sprint-1/refactor/includes.js
+++ b/Sprint-1/refactor/includes.js
@@ -1,8 +1,6 @@
 // Refactor the implementation of includes to use a for...of loop
-
 function includes(list, target) {
-  for (let index = 0; index < list.length; index++) {
-    const element = list[index];
+  for (const element of list) {
     if (element === target) {
       return true;
     }