From 953a7acde601b540b38e722bac9a699b848e77df Mon Sep 17 00:00:00 2001
From: Diana <40689028+ausiejute@users.noreply.github.com>
Date: Sun, 1 Nov 2026 18:48:06 +0000
Subject: [PATCH 01/13] Write required tests

---
 Sprint-1/fix/median.js         | 12 ++++++++++--
 Sprint-1/implement/max.test.js | 34 ++++++++++++++++++++++++++++++++--
 2 files changed, 42 insertions(+), 4 deletions(-)

diff --git a/Sprint-1/fix/median.js b/Sprint-1/fix/median.js
index 5c5b796e1..f97d2e8ac 100644
--- a/Sprint-1/fix/median.js
+++ b/Sprint-1/fix/median.js
@@ -6,8 +6,16 @@
 // 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 median = list.splice(middleIndex, 1)[0];
+  list.forEach((item) => {
+    if (typeof item !== "number")
+      throw new Error("input should be a number value");
+  });
+
+  const sortedList = list.slice().sort((a, b) => a - b);
+
+  // implement median part
+  const middleIndex = Math.floor(sortedList.length / 2);
+  const median = sortedList[middleIndex];
   return median;
 }
 
diff --git a/Sprint-1/implement/max.test.js b/Sprint-1/implement/max.test.js
index ff3fbb5e5..c727883fa 100644
--- a/Sprint-1/implement/max.test.js
+++ b/Sprint-1/implement/max.test.js
@@ -15,29 +15,59 @@ const findMax = require("./max.js");
 // Given an empty array
 // When passed to the max function
 // Then it should return -Infinity
-// Delete this test.todo and replace it with a test.
-test.todo("given an empty array, returns -Infinity");
+
+test("should return -Infinity if given an empty array", () => {
+  expect(findMax([]).toEqual(-Infinity));
+});
 
 // Given an array with one number
 // When passed to the max function
 // Then it should return that number
 
+test("should return that number if given an array with one number", () => {
+  expect(findMax([2]).toEqual(2));
+});
+
 // Given an array with both positive and negative numbers
 // When passed to the max function
 // Then it should return the largest number overall
 
+test("should return the largest number overall if given positive & negative numbers", () => {
+  expect(findMax([-2, 4, -7, 9]).toEqual(9));
+});
+
 // Given an array with just negative numbers
 // When passed to the max function
 // Then it should return the closest one to zero
 
+test("should return the one closest to zero if given only negative numbers", () => {
+  expect(findMax([-2, -4, -7, -9]).toEqual(-2));
+});
+
 // Given an array with decimal numbers
 // When passed to the max function
 // Then it should return the largest decimal number
 
+test("should return the largest decimal number when only decimals were given", () => {
+  expect(findMax([-2.5, 4.1, 3.2, 9.3]).toEqual(9.3));
+});
+
 // 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("should throw an error when at least one value is not a number", () => {
+  expect(() => findMax([-2, "9", "sweet", 9])).toThrow(
+    new Error("findMax requires for all items to be 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")
+
+test("should throw an error when the data type isn't an array", () => {
+  expect(() => findMax(["ten", 1, "thirty"])).toThrow(
+    new Error("findMax requires for input to be a list of items")
+  );
+});

From 646befa539c9db64eec5d5a8d09850fef686ad49 Mon Sep 17 00:00:00 2001
From: Diana <40689028+ausiejute@users.noreply.github.com>
Date: Mon, 2 Nov 2026 00:17:22 +0000
Subject: [PATCH 02/13] Implement the function & correct some test cases

---
 Sprint-1/implement/max.js      | 13 +++++++++++++
 Sprint-1/implement/max.test.js | 12 ++++++------
 2 files changed, 19 insertions(+), 6 deletions(-)

diff --git a/Sprint-1/implement/max.js b/Sprint-1/implement/max.js
index 6dd76378e..16ec000dc 100644
--- a/Sprint-1/implement/max.js
+++ b/Sprint-1/implement/max.js
@@ -1,4 +1,17 @@
 function findMax(elements) {
+  if (!Array.isArray(elements)) {
+    throw new Error("findMax requires an array of numbers");
+  }
+
+  if (elements.length === 0) {
+    return -Infinity;
+  }
+
+  if (!elements.every((element) => typeof element === "number")) {
+    throw new Error("findMax requires for all items to be numbers");
+  }
+
+  return Math.max(...elements);
 }
 
 module.exports = findMax;
diff --git a/Sprint-1/implement/max.test.js b/Sprint-1/implement/max.test.js
index c727883fa..bb9e39a0e 100644
--- a/Sprint-1/implement/max.test.js
+++ b/Sprint-1/implement/max.test.js
@@ -17,7 +17,7 @@ const findMax = require("./max.js");
 // Then it should return -Infinity
 
 test("should return -Infinity if given an empty array", () => {
-  expect(findMax([]).toEqual(-Infinity));
+  expect(findMax([])).toEqual(-Infinity);
 });
 
 // Given an array with one number
@@ -25,7 +25,7 @@ test("should return -Infinity if given an empty array", () => {
 // Then it should return that number
 
 test("should return that number if given an array with one number", () => {
-  expect(findMax([2]).toEqual(2));
+  expect(findMax([2])).toEqual(2);
 });
 
 // Given an array with both positive and negative numbers
@@ -33,7 +33,7 @@ test("should return that number if given an array with one number", () => {
 // Then it should return the largest number overall
 
 test("should return the largest number overall if given positive & negative numbers", () => {
-  expect(findMax([-2, 4, -7, 9]).toEqual(9));
+  expect(findMax([-2, 4, -7, 9])).toEqual(9);
 });
 
 // Given an array with just negative numbers
@@ -41,7 +41,7 @@ test("should return the largest number overall if given positive & negative numb
 // Then it should return the closest one to zero
 
 test("should return the one closest to zero if given only negative numbers", () => {
-  expect(findMax([-2, -4, -7, -9]).toEqual(-2));
+  expect(findMax([-2, -4, -7, -9])).toEqual(-2);
 });
 
 // Given an array with decimal numbers
@@ -49,7 +49,7 @@ test("should return the one closest to zero if given only negative numbers", ()
 // Then it should return the largest decimal number
 
 test("should return the largest decimal number when only decimals were given", () => {
-  expect(findMax([-2.5, 4.1, 3.2, 9.3]).toEqual(9.3));
+  expect(findMax([-2.5, 4.1, 3.2, 9.3])).toEqual(9.3);
 });
 
 // Given an array containing a value that isn't a number
@@ -68,6 +68,6 @@ test("should throw an error when at least one value is not a number", () => {
 
 test("should throw an error when the data type isn't an array", () => {
   expect(() => findMax(["ten", 1, "thirty"])).toThrow(
-    new Error("findMax requires for input to be a list of items")
+    new Error("findMax requires for all items to be numbers")
   );
 });

From 755f69f9cd85949fb316ef647be853fa4ed0a611 Mon Sep 17 00:00:00 2001
From: Diana <40689028+ausiejute@users.noreply.github.com>
Date: Mon, 2 Nov 2026 14:21:45 +0000
Subject: [PATCH 03/13] fix the implementation of  calculateMedian

---
 Sprint-1/fix/median.js | 20 +++++++++++++-------
 1 file changed, 13 insertions(+), 7 deletions(-)

diff --git a/Sprint-1/fix/median.js b/Sprint-1/fix/median.js
index f97d2e8ac..6357c63ac 100644
--- a/Sprint-1/fix/median.js
+++ b/Sprint-1/fix/median.js
@@ -6,16 +6,22 @@
 // or contains values that aren't numbers (the function is expected to throw - see the tests).
 
 function calculateMedian(list) {
-  list.forEach((item) => {
-    if (typeof item !== "number")
-      throw new Error("input should be a number value");
-  });
+  if (!Array.isArray(list) || !list.every((item) => typeof item === "number")) {
+    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.slice().sort((a, b) => a - b);
 
-  // implement median part
-  const middleIndex = Math.floor(sortedList.length / 2);
-  const median = sortedList[middleIndex];
+  const mid = Math.floor(sortedList.length / 2);
+  const median =
+    sortedList.length % 2 !== 0
+      ? sortedList[mid]
+      : (sortedList[mid - 1] + sortedList[mid]) / 2;
+
   return median;
 }
 

From 391d0e5de17feecee2878d1ac1a5cb0f5369c94a Mon Sep 17 00:00:00 2001
From: Diana <40689028+ausiejute@users.noreply.github.com>
Date: Tue, 3 Nov 2026 00:36:55 +0000
Subject: [PATCH 04/13] Fix the calculateMedian implementation

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

diff --git a/Sprint-1/fix/median.js b/Sprint-1/fix/median.js
index 6357c63ac..2756596b4 100644
--- a/Sprint-1/fix/median.js
+++ b/Sprint-1/fix/median.js
@@ -9,6 +9,7 @@ function calculateMedian(list) {
   if (!Array.isArray(list) || !list.every((item) => typeof item === "number")) {
     throw new Error("calculateMedian requires an array of numbers");
   }
+  // test test test
 
   if (list.length === 0) {
     throw new Error("calculateMedian requires a non-empty array");

From a2b4428e883ffdeddd3ea884960aa576412f9316 Mon Sep 17 00:00:00 2001
From: Diana <40689028+ausiejute@users.noreply.github.com>
Date: Tue, 3 Nov 2026 00:38:12 +0000
Subject: [PATCH 05/13] Write the tests and implementation for Sum

---
 Sprint-1/implement/sum.js      | 16 ++++++++++++++++
 Sprint-1/implement/sum.test.js | 23 ++++++++++++++++++++++-
 2 files changed, 38 insertions(+), 1 deletion(-)

diff --git a/Sprint-1/implement/sum.js b/Sprint-1/implement/sum.js
index 9062aafe3..f404246c2 100644
--- a/Sprint-1/implement/sum.js
+++ b/Sprint-1/implement/sum.js
@@ -1,4 +1,20 @@
 function sum(elements) {
+  if (
+    !Array.isArray(elements) ||
+    !elements.every((item) => typeof item === "number")
+  ) {
+    throw new Error("sum requires an array of numbers");
+  }
+
+  if (elements.length === 0) {
+    return 0;
+  }
+
+  let total = 0;
+  for (let i = 0; i < elements.length; i++) {
+    total += elements[i];
+  }
+  return total;
 }
 
 module.exports = sum;
diff --git a/Sprint-1/implement/sum.test.js b/Sprint-1/implement/sum.test.js
index a288e0f0a..de5238d7c 100644
--- a/Sprint-1/implement/sum.test.js
+++ b/Sprint-1/implement/sum.test.js
@@ -13,24 +13,45 @@ 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
+test("should return the same number when given one number", () => {
+  expect(sum([3])).toEqual(3);
+});
 
 // Given an array containing negative numbers
 // When passed to the sum function
 // Then it should still return the correct total sum
+test("should return correct sum when given negative numbers", () => {
+  expect(sum([5, -4, 1, 9])).toEqual(11);
+});
 
 // Given an array with decimal/float numbers
 // When passed to the sum function
 // Then it should return the correct total sum
+test("should return a correct total sum when given decimal/float numbers", () => {
+  expect(sum([2.2, 1, 4.1])).toEqual(7.3);
+});
 
 // 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("should throw an error when passing non-number values", () => {
+  expect(() => sum([8, -3, ""])).toThrow(
+    new Error("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")
+test("should throw an error when passing non-array data types", () => {
+  expect(() => sum("three", {})).toThrow(
+    new Error("sum requires an array of numbers")
+  );
+});

From 6d3d23f38116d1bf5362038d974cf99dc299f709 Mon Sep 17 00:00:00 2001
From: Diana <40689028+ausiejute@users.noreply.github.com>
Date: Tue, 3 Nov 2026 01:07:19 +0000
Subject: [PATCH 06/13] Write required tests for Dedupe

---
 Sprint-1/fix/median.js            |  1 -
 Sprint-1/implement/dedupe.test.js | 17 +++++++++++++++--
 2 files changed, 15 insertions(+), 3 deletions(-)

diff --git a/Sprint-1/fix/median.js b/Sprint-1/fix/median.js
index 2756596b4..6357c63ac 100644
--- a/Sprint-1/fix/median.js
+++ b/Sprint-1/fix/median.js
@@ -9,7 +9,6 @@ function calculateMedian(list) {
   if (!Array.isArray(list) || !list.every((item) => typeof item === "number")) {
     throw new Error("calculateMedian requires an array of numbers");
   }
-  // test test test
 
   if (list.length === 0) {
     throw new Error("calculateMedian requires a non-empty array");
diff --git a/Sprint-1/implement/dedupe.test.js b/Sprint-1/implement/dedupe.test.js
index d7c8e3d8e..655b8a5e5 100644
--- a/Sprint-1/implement/dedupe.test.js
+++ b/Sprint-1/implement/dedupe.test.js
@@ -16,13 +16,26 @@ E.g. dedupe([1, 2, 1]) returns [1, 2]
 // Given an empty array
 // When passed to the dedupe function
 // Then it should return an empty array
-test.todo("given an empty array, it returns an empty array");
+test("given an empty array, it returns an empty array", () => {
+  expect(dedupe([])).toEqual([]);
+});
 
 // Given an array with no duplicates
 // When passed to the dedupe function
 // Then it should return a copy of the original array
+test("should return a copy of the original when the given array has no duplicates", () => {
+  expect(dedupe([1, 3, 8])).toEqual([1, 3, 8]);
+});
 
 // Given an array of strings or numbers
 // When passed to the dedupe function
-// Then it should return a new array with duplicates removed while preserving the 
+// Then it should return a new array with duplicates removed while preserving the
 // first occurrence of each element from the original array.
+test("should return a new array with duplicates removed and 1st occurence of each element preserved", () => {
+  expect(dedupe(["Mon", "wed", "wed", "Sun", "Tue", "Sun"])).toEqual([
+    "Mon",
+    "Wed",
+    "Sun",
+    "Tue",
+  ]);
+});

From 2f157319c7aa1b1b5046556d832ea81c3bb661d6 Mon Sep 17 00:00:00 2001
From: Diana <40689028+ausiejute@users.noreply.github.com>
Date: Tue, 3 Nov 2026 03:01:35 +0000
Subject: [PATCH 07/13] Write the implementation for dedublicate function

---
 Sprint-1/implement/dedupe.js      | 15 ++++++++++++++-
 Sprint-1/implement/dedupe.test.js |  2 +-
 2 files changed, 15 insertions(+), 2 deletions(-)

diff --git a/Sprint-1/implement/dedupe.js b/Sprint-1/implement/dedupe.js
index 781e8718a..0c72150e7 100644
--- a/Sprint-1/implement/dedupe.js
+++ b/Sprint-1/implement/dedupe.js
@@ -1 +1,14 @@
-function dedupe() {}
+function dedupe(items) {
+  if (items.length === 0) {
+    return [];
+  }
+
+  let singleOccur = [];
+  items.forEach((i) => {
+    if (!singleOccur.includes(i)) {
+      singleOccur.push(i);
+    }
+  });
+  return singleOccur;
+}
+module.exports = dedupe;
diff --git a/Sprint-1/implement/dedupe.test.js b/Sprint-1/implement/dedupe.test.js
index 655b8a5e5..0e80143e8 100644
--- a/Sprint-1/implement/dedupe.test.js
+++ b/Sprint-1/implement/dedupe.test.js
@@ -32,7 +32,7 @@ test("should return a copy of the original when the given array has no duplicate
 // Then it should return a new array with duplicates removed while preserving the
 // first occurrence of each element from the original array.
 test("should return a new array with duplicates removed and 1st occurence of each element preserved", () => {
-  expect(dedupe(["Mon", "wed", "wed", "Sun", "Tue", "Sun"])).toEqual([
+  expect(dedupe(["Mon", "Wed", "Wed", "Sun", "Tue", "Sun"])).toEqual([
     "Mon",
     "Wed",
     "Sun",

From 7c2c9cd1605973202a6d89cda39a089af69c9e86 Mon Sep 17 00:00:00 2001
From: Diana <40689028+ausiejute@users.noreply.github.com>
Date: Tue, 3 Nov 2026 12:34:53 +0000
Subject: [PATCH 08/13] Write required describe-median tests

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

diff --git a/Sprint-1/implement/describe-median.test.js b/Sprint-1/implement/describe-median.test.js
index e7d18a264..58ebb43d4 100644
--- a/Sprint-1/implement/describe-median.test.js
+++ b/Sprint-1/implement/describe-median.test.js
@@ -21,12 +21,28 @@ 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"');
+describe("calculateMedian", () => {
+  test('returns "The median is " followed by the median', () => {
+    expect(calculateMedian([3, 1, 4, 1, 5])).toBe(3);
+  });
+});
 
 // Given an empty array
 // When passed to describeMedian
 // Then it should return "Could not calculate a median: calculateMedian requires a non-empty array"
+test("returns error message when given an empty array", () => {
+  const result = calculateMedian([]);
+  expect(result.error).toBe(
+    "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("returns error message when given a non-array data", () => {
+  const result = calculateMedian("five seven nine");
+  expect(result.error).toBe(
+    "Could not calculate a median: calculateMedian requires an array of numbers"
+  );
+});

From 2c6d2d0b8fbcc1b8efb2fc3837c4bb89834a085a Mon Sep 17 00:00:00 2001
From: Diana <40689028+ausiejute@users.noreply.github.com>
Date: Tue, 3 Nov 2026 12:54:22 +0000
Subject: [PATCH 09/13] Implement describe-median function

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

diff --git a/Sprint-1/implement/describe-median.js b/Sprint-1/implement/describe-median.js
index 3381cfc0a..ebdf1cfe9 100644
--- a/Sprint-1/implement/describe-median.js
+++ b/Sprint-1/implement/describe-median.js
@@ -20,6 +20,13 @@ function calculateMedian(list) {
 }
 
 // Implement this function. See describe-median.test.js for the acceptance criteria.
-function describeMedian(list) {}
+function describeMedian(list) {
+  try {
+    const median = calculateMedian(list);
+    return `The median is ${median}`;
+  } catch (err) {
+    return err.message;
+  }
+}
 
 module.exports = describeMedian;

From eef2d6bcbfc17d85f07266ad643dafb92f56a431 Mon Sep 17 00:00:00 2001
From: Diana <40689028+ausiejute@users.noreply.github.com>
Date: Tue, 3 Nov 2026 13:06:46 +0000
Subject: [PATCH 10/13] Fix  naming and final checkups

---
 Sprint-1/implement/describe-median.js      |  2 +-
 Sprint-1/implement/describe-median.test.js | 14 +++++++-------
 2 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/Sprint-1/implement/describe-median.js b/Sprint-1/implement/describe-median.js
index ebdf1cfe9..488bffa1c 100644
--- a/Sprint-1/implement/describe-median.js
+++ b/Sprint-1/implement/describe-median.js
@@ -25,7 +25,7 @@ function describeMedian(list) {
     const median = calculateMedian(list);
     return `The median is ${median}`;
   } catch (err) {
-    return err.message;
+    return `Could not calculate a median: ${err.message}`;
   }
 }
 
diff --git a/Sprint-1/implement/describe-median.test.js b/Sprint-1/implement/describe-median.test.js
index 58ebb43d4..7225f1b38 100644
--- a/Sprint-1/implement/describe-median.test.js
+++ b/Sprint-1/implement/describe-median.test.js
@@ -21,9 +21,9 @@ 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.
-describe("calculateMedian", () => {
+describe("describeMedian", () => {
   test('returns "The median is " followed by the median', () => {
-    expect(calculateMedian([3, 1, 4, 1, 5])).toBe(3);
+    expect(describeMedian([3, 1, 4, 1, 5])).toBe("The median is 3");
   });
 });
 
@@ -31,8 +31,8 @@ describe("calculateMedian", () => {
 // When passed to describeMedian
 // Then it should return "Could not calculate a median: calculateMedian requires a non-empty array"
 test("returns error message when given an empty array", () => {
-  const result = calculateMedian([]);
-  expect(result.error).toBe(
+  const result = describeMedian([]);
+  expect(result).toBe(
     "Could not calculate a median: calculateMedian requires a non-empty array"
   );
 });
@@ -40,9 +40,9 @@ test("returns error message when given an 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("returns error message when given a non-array data", () => {
-  const result = calculateMedian("five seven nine");
-  expect(result.error).toBe(
+test("returns error message when given a non-array", () => {
+  const result = describeMedian("five seven nine");
+  expect(result).toBe(
     "Could not calculate a median: calculateMedian requires an array of numbers"
   );
 });

From bea2f8dc81afcf51d195816a74cd8bac08109155 Mon Sep 17 00:00:00 2001
From: Diana <40689028+ausiejute@users.noreply.github.com>
Date: Tue, 3 Nov 2026 17:56:42 +0000
Subject: [PATCH 11/13] Write required tests and implementation of
 calculateMean

---
 Sprint-1/implement/mean.js      | 15 ++++++++++++++-
 Sprint-1/implement/mean.test.js | 32 +++++++++++++++++++++++++++++++-
 2 files changed, 45 insertions(+), 2 deletions(-)

diff --git a/Sprint-1/implement/mean.js b/Sprint-1/implement/mean.js
index 36909ea1f..979f588df 100644
--- a/Sprint-1/implement/mean.js
+++ b/Sprint-1/implement/mean.js
@@ -1,3 +1,16 @@
-function calculateMean(list) {}
+function calculateMean(list) {
+  if (list.length === 0) {
+    throw new Error("calculateMean requires a non-empty array");
+  }
+
+  if (!Array.isArray(list) || !list.every((item) => typeof item === "number")) {
+    throw new Error("calculateMean requires an array of numbers");
+  }
+
+  let sum = list.reduce((a, b) => a + b, 0);
+
+  let meanResult = sum / list.length;
+  return meanResult;
+}
 
 module.exports = calculateMean;
diff --git a/Sprint-1/implement/mean.test.js b/Sprint-1/implement/mean.test.js
index 847b88676..e06bf8375 100644
--- a/Sprint-1/implement/mean.test.js
+++ b/Sprint-1/implement/mean.test.js
@@ -23,28 +23,58 @@ 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");
+describe("calculatemean", () => {
+  it("returns the mean for [1, 2, 6]", () => {
+    expect(calculateMean([])).toEqual();
+  });
+});
 
 // Given an array with a single number
 // When passed to calculateMean
 // Then it should return that number
+it("returns the mean for [1, 2, 6]", () => {
+  expect(calculateMean([1, 2, 6])).toEqual(3);
+});
 
 // Given an array containing negative or decimal numbers
 // When passed to calculateMean
 // Then it should return the correct mean
+it("returns the mean for [-1, 2.5, 6]", () => {
+  expect(calculateMean([])).toEqual(2.5);
+});
 
 // Given an empty array
 // When passed to calculateMean
 // Then it should throw Error("calculateMean requires a non-empty array")
+it("throws when given an empty array", () => {
+  expect(() => calculateMean([])).toThrow(
+    new Error("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")
+it("throws when given a non-array", () => {
+  expect(() => calculateMean("luck")).toThrow(
+    new 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")
+it("throws when not given any argument", () => {
+  expect(() => calculateMean([])).toThrow(
+    new 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")
+it("throws when given an array containing a non-number value", () => {
+  expect(() => calculateMean(["two", five, "8"])).toThrow(
+    new Error("calculateMean requires an array of numbers")
+  );
+});

From fdb26e8f56908d94a969a5d9eebb8cd278cf0e57 Mon Sep 17 00:00:00 2001
From: Diana <40689028+ausiejute@users.noreply.github.com>
Date: Tue, 3 Nov 2026 23:20:43 +0000
Subject: [PATCH 12/13] Fix and adjust implementation and tests of
 calculateMean

---
 .gitignore                      |  2 ++
 Sprint-1/implement/mean.js      |  8 ++++++--
 Sprint-1/implement/mean.test.js | 12 ++++++------
 3 files changed, 14 insertions(+), 8 deletions(-)

diff --git a/.gitignore b/.gitignore
index 8ee70353f..e1ce8e68a 100644
--- a/.gitignore
+++ b/.gitignore
@@ -4,3 +4,5 @@ node_modules
 **/.DS_Store
 .idea
 package-lock.json
+mean.js
+mean.test.js
diff --git a/Sprint-1/implement/mean.js b/Sprint-1/implement/mean.js
index 979f588df..e89828027 100644
--- a/Sprint-1/implement/mean.js
+++ b/Sprint-1/implement/mean.js
@@ -1,9 +1,13 @@
 function calculateMean(list) {
-  if (list.length === 0) {
+  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");
   }
 
-  if (!Array.isArray(list) || !list.every((item) => typeof item === "number")) {
+  if (!list.every((item) => typeof item === "number")) {
     throw new Error("calculateMean requires an array of numbers");
   }
 
diff --git a/Sprint-1/implement/mean.test.js b/Sprint-1/implement/mean.test.js
index e06bf8375..8e9b24f73 100644
--- a/Sprint-1/implement/mean.test.js
+++ b/Sprint-1/implement/mean.test.js
@@ -25,22 +25,22 @@ const calculateMean = require("./mean.js");
 // Delete this test.todo and replace it with a test.
 describe("calculatemean", () => {
   it("returns the mean for [1, 2, 6]", () => {
-    expect(calculateMean([])).toEqual();
+    expect(calculateMean([1, 2, 6])).toEqual(3);
   });
 });
 
 // Given an array with a single number
 // When passed to calculateMean
 // Then it should return that number
-it("returns the mean for [1, 2, 6]", () => {
-  expect(calculateMean([1, 2, 6])).toEqual(3);
+it("returns the mean for 3", () => {
+  expect(calculateMean([3])).toEqual(3);
 });
 
 // Given an array containing negative or decimal numbers
 // When passed to calculateMean
 // Then it should return the correct mean
 it("returns the mean for [-1, 2.5, 6]", () => {
-  expect(calculateMean([])).toEqual(2.5);
+  expect(calculateMean([-1, 2.5, 6])).toEqual(2.5);
 });
 
 // Given an empty array
@@ -65,7 +65,7 @@ it("throws when given a non-array", () => {
 // When passed to calculateMean
 // Then it should throw Error("calculateMean requires an array of numbers")
 it("throws when not given any argument", () => {
-  expect(() => calculateMean([])).toThrow(
+  expect(() => calculateMean()).toThrow(
     new Error("calculateMean requires an array of numbers")
   );
 });
@@ -74,7 +74,7 @@ it("throws when not given any argument", () => {
 // When passed to calculateMean
 // Then it should throw Error("calculateMean requires an array of numbers")
 it("throws when given an array containing a non-number value", () => {
-  expect(() => calculateMean(["two", five, "8"])).toThrow(
+  expect(() => calculateMean(["two", 5, "8"])).toThrow(
     new Error("calculateMean requires an array of numbers")
   );
 });

From bdf37ad5e1d0757e616ded341bfcc65b40e4125a Mon Sep 17 00:00:00 2001
From: Diana <40689028+ausiejute@users.noreply.github.com>
Date: Wed, 4 Nov 2026 01:11:24 +0000
Subject: [PATCH 13/13] Refactor the implementation of Includes function

---
 Sprint-1/refactor/includes.js | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/Sprint-1/refactor/includes.js b/Sprint-1/refactor/includes.js
index 29dad81f0..8c9ae2e66 100644
--- a/Sprint-1/refactor/includes.js
+++ b/Sprint-1/refactor/includes.js
@@ -1,8 +1,7 @@
 // Refactor the implementation of includes to use a for...of loop
 
 function includes(list, target) {
-  for (let index = 0; index < list.length; index++) {
-    const element = list[index];
+  for (const element of list) {
     if (element === target) {
       return true;
     }