From 5c5e165e270770b5ad92977c959f65afff382da3 Mon Sep 17 00:00:00 2001
From: Arunkumar Akilan <arunkumarakilanarun@gmail.com>
Date: Mon, 9 Mar 2026 20:29:04 +0000
Subject: [PATCH 01/15] fix: handle non-array and non-numeric inputs in
 calculateMedian

---
 Sprint-1/fix/median.js | 38 +++++++++++++++++++++++++++++++++++---
 1 file changed, 35 insertions(+), 3 deletions(-)

diff --git a/Sprint-1/fix/median.js b/Sprint-1/fix/median.js
index b22590bc6..c593f1811 100644
--- a/Sprint-1/fix/median.js
+++ b/Sprint-1/fix/median.js
@@ -6,9 +6,41 @@
 // 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;
+  let newArray = [];
+  if(!Array.isArray(list))
+    {
+      return null;
+    }
+   
+  for (const item of list)
+  {
+    if (typeof item === 'number')
+    {
+      newArray.push(item);
+    } 
+
+  }
+  if (newArray.length === 0)
+  {
+    return null;
+  }
+  newArray = newArray.sort((a, b) => a-b);
+  if(newArray.length %2 === 0)
+  {
+     const rightIndex = newArray.length/2
+     const leftIndex = rightIndex - 1;
+     const median = (newArray[rightIndex] + newArray[leftIndex])/2;
+     return median;
+
+  }
+  else{
+
+    const middleIndex = Math.floor(newArray.length/2);
+    return newArray[middleIndex]
+  }
+  //const middleIndex = Math.floor(newArray.length / 2);
+  //const median = list.splice(middleIndex, 1)[0];
+  //return newArray[middleIndex];
 }
 
 module.exports = calculateMedian;

From 4700cb12ac3bd3a4795eb6111ed93873366ac786 Mon Sep 17 00:00:00 2001
From: Arunkumar Akilan <arunkumarakilanarun@gmail.com>
Date: Tue, 10 Mar 2026 18:45:13 +0000
Subject: [PATCH 02/15] Implement dedupe function

---
 Sprint-1/implement/dedupe.js      | 18 +++++++++++++++++-
 Sprint-1/implement/dedupe.test.js | 13 ++++++++++++-
 2 files changed, 29 insertions(+), 2 deletions(-)

diff --git a/Sprint-1/implement/dedupe.js b/Sprint-1/implement/dedupe.js
index 781e8718a..b19b591e3 100644
--- a/Sprint-1/implement/dedupe.js
+++ b/Sprint-1/implement/dedupe.js
@@ -1 +1,17 @@
-function dedupe() {}
+function dedupe(list) {
+  if (list.length=== 0)
+    {
+        return [];
+    }
+     let result = [];
+  for (let item of list)
+  {
+    if(!result.includes(item))
+    {
+        result.push(item)
+    }
+    }
+    return result;
+ 
+}
+module.exports = dedupe;
\ No newline at end of file
diff --git a/Sprint-1/implement/dedupe.test.js b/Sprint-1/implement/dedupe.test.js
index 23e0f8638..04d0edaa6 100644
--- a/Sprint-1/implement/dedupe.test.js
+++ b/Sprint-1/implement/dedupe.test.js
@@ -17,7 +17,18 @@ E.g. dedupe([1, 2, 1]) target output: [1, 2]
 // 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", ()=>{
+    const list = [];
+    expect(dedupe(list)).toEqual([]);
+});
+test
+("array with no duplicate should return copy of original", ()=>{
+    let list = [1,2,4,6,9,8];
+    expect(dedupe(list)).toEqual([1,2,4,6,9,8]);
+});
+test("shoiuld remove the duplicate value and preserving the first occurebce",()=>{
+    expect(dedupe([5, 1, 1, 2, 3, 2, 5, 8])).toEqual([5,1,2,3,8]);
+})
 // Given an array with no duplicates
 // When passed to the dedupe function
 // Then it should return a copy of the original array

From 2b3cdc0ad01a6e4b68b4a9a3b7d2187d35d8e92e Mon Sep 17 00:00:00 2001
From: Arunkumar Akilan <arunkumarakilanarun@gmail.com>
Date: Tue, 10 Mar 2026 20:25:32 +0000
Subject: [PATCH 03/15] Implement findMax function and ignore non-numeric
 values

---
 Sprint-1/implement/max.js      | 15 +++++++++++++++
 Sprint-1/implement/max.test.js | 29 ++++++++++++++++++++++++++++-
 2 files changed, 43 insertions(+), 1 deletion(-)

diff --git a/Sprint-1/implement/max.js b/Sprint-1/implement/max.js
index 6dd76378e..e69260ad5 100644
--- a/Sprint-1/implement/max.js
+++ b/Sprint-1/implement/max.js
@@ -1,4 +1,19 @@
 function findMax(elements) {
+    if(elements.length === 0)
+    {
+        return -Infinity;
+    }
+    let max = -Infinity ;
+    for (const item of elements)
+{
+    if (typeof item === 'number')
+    {
+    max =  Math.max(max , item);
+    }
+    
+
+}
+  return max;
 }
 
 module.exports = findMax;
diff --git a/Sprint-1/implement/max.test.js b/Sprint-1/implement/max.test.js
index 82f18fd88..afcf84bdc 100644
--- a/Sprint-1/implement/max.test.js
+++ b/Sprint-1/implement/max.test.js
@@ -16,7 +16,34 @@ 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", () => {
+  const list = [];
+  expect(findMax(list)).toEqual(-Infinity);
+});
+test("Array with one number should return that number", () => {
+    const list =[7];
+    expect(findMax(list)).toEqual(7);
+});
+test("An array with both positive and negative number should return the largest overall", () =>{
+    const list = [-10, 5, 30, -3];
+    expect(findMax(list)).toEqual(30);
+});
+test("Array with just negative number should return the closest on to zero", () =>{
+    const list = [-10, -3, -20,-7,-4]
+    expect(findMax(list)).toEqual(-3);
+});
+test("An array with decimal number should return largest decimal number", ()=>{
+   const list = [1.2, 3.5, 2.8]
+    expect(findMax(list)).toEqual(3.5);
+});
+test("An array with non-numeric values should return the max and ignore non-numeric", () =>{
+    const list = ['hey', 10, 'hi', 60, 50];
+    expect(findMax(list)).toEqual(60);
+});
+test("An array with non numeric value should  return the least surprising value given how it behaves for all other inputs", ()=> {
+    const list = ['a', 'b', 'hello'];
+    expect(findMax(list)).toEqual(-Infinity);
+})
 
 // Given an array with one number
 // When passed to the max function

From f59026c5cc6956e22c3443cb948f283b9f547c77 Mon Sep 17 00:00:00 2001
From: Arunkumar Akilan <arunkumarakilanarun@gmail.com>
Date: Tue, 10 Mar 2026 20:51:53 +0000
Subject: [PATCH 04/15] Implement sum function

---
 Sprint-1/implement/sum.js      | 15 +++++++++++++++
 Sprint-1/implement/sum.test.js | 29 ++++++++++++++++++++++++++++-
 2 files changed, 43 insertions(+), 1 deletion(-)

diff --git a/Sprint-1/implement/sum.js b/Sprint-1/implement/sum.js
index 9062aafe3..7bb139801 100644
--- a/Sprint-1/implement/sum.js
+++ b/Sprint-1/implement/sum.js
@@ -1,4 +1,19 @@
 function sum(elements) {
+    if (elements.length === 0)
+    {
+        return 0;
+    }
+      let total = 0 ;
+    for (const item of elements)
+{
+    if (typeof item === 'number')
+    {
+     total =  total + item;
+    }
+    
+
+}
+  return total;
 }
 
 module.exports = sum;
diff --git a/Sprint-1/implement/sum.test.js b/Sprint-1/implement/sum.test.js
index dd0a090ca..0598d34ab 100644
--- a/Sprint-1/implement/sum.test.js
+++ b/Sprint-1/implement/sum.test.js
@@ -13,7 +13,34 @@ 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 should return -Infinity", () => {
+  const list = [];
+  expect(sum(list)).toEqual(0);
+});
+test("Array with one number should return that number", () => {
+    const list =[7];
+    expect(sum(list)).toEqual(7);
+});
+test("An array with both positive and negative number should return the largest overall", () =>{
+    const list = [-10, 5, 30, -3];
+    expect(sum(list)).toEqual(22);
+});
+test("Array with just negative number should return the closest on to zero", () =>{
+    const list = [-10, -3, -20,-7,-4]
+    expect(sum(list)).toEqual(-44);
+});
+test("An array with decimal number should return largest decimal number", ()=>{
+   const list = [1.2, 3.5, 2.8]
+    expect(sum(list)).toEqual(7.5);
+});
+test("An array with non-numeric values should return the max and ignore non-numeric", () =>{
+    const list = ['hey', 10, 'hi', 60, 50];
+    expect(sum(list)).toEqual(120);
+});
+test("An array with non numeric value should  return the least surprising value given how it behaves for all other inputs", ()=> {
+    const list = ['a', 'b', 'hello'];
+    expect(sum(list)).toEqual(0);
+})
 
 // Given an array with just one number
 // When passed to the sum function

From b473ef0fa3fde08b49048086b8fe53f70f55c273 Mon Sep 17 00:00:00 2001
From: Arunkumar Akilan <arunkumarakilanarun@gmail.com>
Date: Wed, 11 Mar 2026 10:19:18 +0000
Subject: [PATCH 05/15] Refactor includes to use for...of loop

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

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

From dba93c73529424f25b81f606d10114337622dbf2 Mon Sep 17 00:00:00 2001
From: Arunkumar Akilan <arunkumarakilanarun@gmail.com>
Date: Sat, 14 Mar 2026 23:18:06 +0000
Subject: [PATCH 06/15] fix: correct property access to retrieve houseNumber
 from address object

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

diff --git a/Sprint-2/debug/address.js b/Sprint-2/debug/address.js
index 940a6af83..fde180d6d 100644
--- a/Sprint-2/debug/address.js
+++ b/Sprint-2/debug/address.js
@@ -12,4 +12,4 @@ const address = {
   postcode: "XYZ 123",
 };
 
-console.log(`My house number is ${address[0]}`);
+console.log(`My house number is ${address["houseNumber"]}`);

From 00cbd0933891eb315c2be60791fb74737ea4bdd8 Mon Sep 17 00:00:00 2001
From: Arunkumar Akilan <arunkumarakilanarun@gmail.com>
Date: Sat, 14 Mar 2026 23:52:09 +0000
Subject: [PATCH 07/15] fix: iterate through ingredients array to print each
 ingredient

---
 Sprint-2/debug/recipe.js | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

diff --git a/Sprint-2/debug/recipe.js b/Sprint-2/debug/recipe.js
index 6cbdd22cd..15a450935 100644
--- a/Sprint-2/debug/recipe.js
+++ b/Sprint-2/debug/recipe.js
@@ -1,5 +1,6 @@
 // Predict and explain first...
-
+//The title and serves values print correctly because the properties are accessed directly using 
+// recipe.title and recipe.serves.
 // This program should log out the title, how many it serves and the ingredients.
 // Each ingredient should be logged on a new line
 // How can you fix it?
@@ -10,6 +11,11 @@ const recipe = {
   ingredients: ["olive oil", "tomatoes", "salt", "pepper"],
 };
 
-console.log(`${recipe.title} serves ${recipe.serves}
-  ingredients:
-${recipe}`);
+console.log(`${recipe.title} serves ${recipe.serves}`);
+for(const ingredients of recipe.ingredients)
+{
+  console.log(`*${ingredients}`)
+}
+
+//The program prints the recipe title and number of servings. 
+// Then it loops through the ingredients array and logs each ingredient on a new line so they are displayed individually instead of printing the whole object.
\ No newline at end of file

From aebc4bd4ab9e3db555316e1d347ebcbce77cc8c1 Mon Sep 17 00:00:00 2001
From: Arunkumar Akilan <arunkumarakilanarun@gmail.com>
Date: Sun, 15 Mar 2026 00:17:51 +0000
Subject: [PATCH 08/15] fix: log all author object values using Object.values

---
 Sprint-2/debug/author.js | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/Sprint-2/debug/author.js b/Sprint-2/debug/author.js
index 8c2125977..876962002 100644
--- a/Sprint-2/debug/author.js
+++ b/Sprint-2/debug/author.js
@@ -1,5 +1,6 @@
 // Predict and explain first...
-
+// The program throws an error because a for...of loop only works with iterable values like arrays or strings. 
+// The author variable is an object, which is not iterable by default, so JavaScript cannot loop through it.
 // This program attempts to log out all the property values in the object.
 // But it isn't working. Explain why first and then fix the problem
 
@@ -10,7 +11,11 @@ const author = {
   age: 40,
   alive: true,
 };
-
-for (const value of author) {
-  console.log(value);
+const values = Object.values(author);
+for(const item of values)
+{
+    console.log(item);
 }
+
+ 
+

From 964724902b0bc8907a22ef252403da8dc3a1227c Mon Sep 17 00:00:00 2001
From: Arunkumar Akilan <arunkumarakilanarun@gmail.com>
Date: Sun, 15 Mar 2026 07:03:12 +0000
Subject: [PATCH 09/15] feat: implement createLookup to convert
 country-currency pairs into lookup object

---
 Sprint-2/implement/lookup.js      | 10 ++++++++--
 Sprint-2/implement/lookup.test.js |  9 +++++++++
 2 files changed, 17 insertions(+), 2 deletions(-)

diff --git a/Sprint-2/implement/lookup.js b/Sprint-2/implement/lookup.js
index a6746e07f..e5f1addc0 100644
--- a/Sprint-2/implement/lookup.js
+++ b/Sprint-2/implement/lookup.js
@@ -1,5 +1,11 @@
-function createLookup() {
-  // implementation here
+function createLookup(countryCurrencyPairs) {
+  const countryCurrencyLookup = {};
+
+  for (let item of countryCurrencyPairs) {
+    const [key, value] = [item[0], item[1]];
+   countryCurrencyLookup[key] = value;
+  }
+  return countryCurrencyLookup;
 }
 
 module.exports = createLookup;
diff --git a/Sprint-2/implement/lookup.test.js b/Sprint-2/implement/lookup.test.js
index 547e06c5a..a1b82e864 100644
--- a/Sprint-2/implement/lookup.test.js
+++ b/Sprint-2/implement/lookup.test.js
@@ -2,6 +2,15 @@ const createLookup = require("./lookup.js");
 
 test.todo("creates a country currency code lookup for multiple codes");
 
+test("An array of arrays representing country code and currency code should return an object where the keys are country code values are currency code",()=>{
+  const countryCurrencyPairs = [['IND', 'INR'], ['US', 'USD'], ['UK', 'GBR'], ['CA','CAD'] ];
+ expect(createLookup(countryCurrencyPairs)).toEqual({
+   IND: "INR",
+   US: "USD",
+   UK: "GBR",
+   CA: "CAD",
+ });
+})
 /*
 
 Create a lookup object of key value pairs from an array of code pairs

From e4b21305b71519a8052544ccb5e52b570c7dff0f Mon Sep 17 00:00:00 2001
From: Arunkumar Akilan <arunkumarakilanarun@gmail.com>
Date: Sun, 15 Mar 2026 08:25:31 +0000
Subject: [PATCH 10/15] fix: improve querystring parser and add edge case tests

---
 Sprint-2/implement/querystring.js      |  6 ++++--
 Sprint-2/implement/querystring.test.js | 15 +++++++++++++++
 2 files changed, 19 insertions(+), 2 deletions(-)

diff --git a/Sprint-2/implement/querystring.js b/Sprint-2/implement/querystring.js
index 45ec4e5f3..118a27b53 100644
--- a/Sprint-2/implement/querystring.js
+++ b/Sprint-2/implement/querystring.js
@@ -5,8 +5,10 @@ function parseQueryString(queryString) {
   }
   const keyValuePairs = queryString.split("&");
 
-  for (const pair of keyValuePairs) {
-    const [key, value] = pair.split("=");
+  for (const item of keyValuePairs) {
+    const pair = item.split("=");
+    const key = pair.shift();
+    const value = pair.join("=");
     queryParams[key] = value;
   }
 
diff --git a/Sprint-2/implement/querystring.test.js b/Sprint-2/implement/querystring.test.js
index 3e218b789..c5681bec4 100644
--- a/Sprint-2/implement/querystring.test.js
+++ b/Sprint-2/implement/querystring.test.js
@@ -10,3 +10,18 @@ test("parses querystring values containing =", () => {
     "equation": "x=y+1",
   });
 });
+test("An empty string should return an empty object",()=>{
+  expect(parseQueryString("")).toEqual({});
+});
+test("parses querystring parameters with an empty value",()=>{
+  expect(parseQueryString("name=")).toEqual({name :""});
+});
+test("handles querystring parameters that have no = sign",()=>{
+  expect(parseQueryString("flag")).toEqual({flag:""})
+});
+test("parses querystring values containing multiple = characters",()=>{
+  expect(parseQueryString("token=a=b=c=d")).toEqual({token:"a=b=c=d"});
+});
+test("handles multiple querystring parameters when one value contains =",()=>{
+  expect(parseQueryString("a=1&equation=x=y+1")).toEqual({a:"1", equation:"x=y+1"});
+});

From f5665eb3766d2837f90dd2ca905cfd10e9627cad Mon Sep 17 00:00:00 2001
From: Arunkumar Akilan <arunkumarakilanarun@gmail.com>
Date: Sun, 15 Mar 2026 12:10:58 +0000
Subject: [PATCH 11/15] test: add tests for contains function and fix toThrow
 usage

---
 Sprint-2/implement/contains.js      | 20 +++++++++++++++++++-
 Sprint-2/implement/contains.test.js | 22 ++++++++++++++++++++++
 2 files changed, 41 insertions(+), 1 deletion(-)

diff --git a/Sprint-2/implement/contains.js b/Sprint-2/implement/contains.js
index cd779308a..8cee952a2 100644
--- a/Sprint-2/implement/contains.js
+++ b/Sprint-2/implement/contains.js
@@ -1,3 +1,21 @@
-function contains() {}
+function contains(object, propertyName) {
+    if(typeof object !== 'object' || Array.isArray(object) || object=== null)
+    {
+        throw new Error("It is a invalid object")
+    }
+    const newArray = Object.keys(object);
+    for(let item of newArray)
+    {
+       if (item === propertyName)
+        {
+          return true
+       }
+       
+       
+       
+    }
+    return false;
+}
+
 
 module.exports = contains;
diff --git a/Sprint-2/implement/contains.test.js b/Sprint-2/implement/contains.test.js
index 326bdb1f2..0f020858d 100644
--- a/Sprint-2/implement/contains.test.js
+++ b/Sprint-2/implement/contains.test.js
@@ -11,6 +11,28 @@ E.g. contains({a: 1, b: 2}, 'c') // returns false
 as the object doesn't contains a key of 'c'
 */
 
+test("An empty object should return false",()=>{
+    const object = {};
+    const propertyName = "a";
+    expect(contains(object, propertyName)).toEqual(false);
+});
+  
+
+test("returns true when the object contains an existing property name", () => {
+  const object = { a: 1, b: 2, c: 3 };
+  const propertyName = "a";
+  expect(contains(object, propertyName)).toEqual(true);
+});
+test("returns false when the object not contains an existing property name", () => {
+  const object = { a: 1, b: 2, c: 3 };
+  const propertyName = "d";
+  expect(contains(object, propertyName)).toEqual(false);
+});
+test("Should throw an error for an invalid parameters", () => {
+  const object = [1,2,3,4,5,6,7];
+  const propertyName = "a";
+  expect(() => contains(object, propertyName)).toThrow();
+});
 // Acceptance criteria:
 
 // Given a contains function

From d15e236c9737efcf6264cdb7afbea69fdd12627c Mon Sep 17 00:00:00 2001
From: Arunkumar Akilan <arunkumarakilanarun@gmail.com>
Date: Sun, 15 Mar 2026 12:13:11 +0000
Subject: [PATCH 12/15] test: add tests for contains function and fix toThrow
 usage

---
 Sprint-2/implement/contains.test.js | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/Sprint-2/implement/contains.test.js b/Sprint-2/implement/contains.test.js
index 0f020858d..b64015f11 100644
--- a/Sprint-2/implement/contains.test.js
+++ b/Sprint-2/implement/contains.test.js
@@ -33,6 +33,16 @@ test("Should throw an error for an invalid parameters", () => {
   const propertyName = "a";
   expect(() => contains(object, propertyName)).toThrow();
 });
+test("Should throw an error for an invalid parameters", () => {
+  const object = null;
+  const propertyName = "a";
+  expect(() => contains(object, propertyName)).toThrow();
+});
+test("Should throw an error for an invalid parameters", () => {
+  const object = "hi";
+  const propertyName = "a";
+  expect(() => contains(object, propertyName)).toThrow();
+});
 // Acceptance criteria:
 
 // Given a contains function

From e34b8ed3ba107df756309a7d39a5ae56efa2630a Mon Sep 17 00:00:00 2001
From: Arunkumar Akilan <arunkumarakilanarun@gmail.com>
Date: Mon, 16 Mar 2026 20:33:27 +0000
Subject: [PATCH 13/15] fix: correct tally test to call the tally function

---
 Sprint-2/implement/tally.js      | 17 ++++++++++++++++-
 Sprint-2/implement/tally.test.js |  9 +++++++++
 2 files changed, 25 insertions(+), 1 deletion(-)

diff --git a/Sprint-2/implement/tally.js b/Sprint-2/implement/tally.js
index f47321812..88ff23bb1 100644
--- a/Sprint-2/implement/tally.js
+++ b/Sprint-2/implement/tally.js
@@ -1,3 +1,18 @@
-function tally() {}
+function tally(arr) {
+    const object = {};
+    if(!Array.isArray(arr))
+    {
+        throw new Error("Invalid input: tally expects an array");
+    }
+    if(arr.length === 0)
+    {
+        return object;
+    } 
+    arr.forEach(ele =>{
+        object[ele] =(object[ele] || 0) + 1;
+
+    });
+    return object;
+}
 
 module.exports = tally;
diff --git a/Sprint-2/implement/tally.test.js b/Sprint-2/implement/tally.test.js
index 2ceffa8dd..691b622be 100644
--- a/Sprint-2/implement/tally.test.js
+++ b/Sprint-2/implement/tally.test.js
@@ -13,6 +13,15 @@ const tally = require("./tally.js");
  * tally(['a', 'a', 'a']), target output: { a: 3 }
  * tally(['a', 'a', 'b', 'c']), target output: { a : 2, b: 1, c: 1 }
  */
+test("throws an error when the input is not an array", ()=>{
+    expect(()=>tally("hi")).toThrow();
+});
+test("returns an empty object when the input array is empty",()=>{
+    expect(tally([])).toEqual({});
+});
+test("returns the count of each unique item in the array", ()=>{
+    expect(tally(['a','b','a','c','b','a'])).toEqual({a:3,b:2,c:1})
+});
 
 // Acceptance criteria:
 

From 575847d16b7d7a5d50bc885879ffb9828b4945d4 Mon Sep 17 00:00:00 2001
From: Arunkumar Akilan <arunkumarakilanarun@gmail.com>
Date: Tue, 17 Mar 2026 08:19:49 +0000
Subject: [PATCH 14/15] feat: implement invert function and add tests for
 key-value swapping

---
 Sprint-2/interpret/invert.js      | 11 +++++++++--
 Sprint-2/interpret/invert.test.js | 10 ++++++++++
 2 files changed, 19 insertions(+), 2 deletions(-)
 create mode 100644 Sprint-2/interpret/invert.test.js

diff --git a/Sprint-2/interpret/invert.js b/Sprint-2/interpret/invert.js
index bb353fb1f..0cdc4da5e 100644
--- a/Sprint-2/interpret/invert.js
+++ b/Sprint-2/interpret/invert.js
@@ -9,21 +9,28 @@
 function invert(obj) {
   const invertedObj = {};
 
-  for (const [key, value] of Object.entries(obj)) {
-    invertedObj.key = value;
+  for (const [value, key] of Object.entries(obj)) {
+    invertedObj[key] = value;
   }
 
   return invertedObj;
 }
 
+module.exports = invert;
 // a) What is the current return value when invert is called with { a : 1 }
+//{key:1}
 
 // b) What is the current return value when invert is called with { a: 1, b: 2 }
+//{key:1, key : 2}
 
 // c) What is the target return value when invert is called with {a : 1, b: 2}
+// {'1':'a','2':'b'}
 
 // c) What does Object.entries return? Why is it needed in this program?
+// Object.entries() returns an array of [key, value] pairs from an object. It is used here to loop through the object and access both the key and value in each iteration.
 
 // d) Explain why the current return value is different from the target output
+// The return value is different because the program uses dot notation with a variable instead of bracket notation.
+//  Also, the object needs to be inverted, so the key and value must be swapped when iterating through the entries.
 
 // e) Fix the implementation of invert (and write tests to prove it's fixed!)
diff --git a/Sprint-2/interpret/invert.test.js b/Sprint-2/interpret/invert.test.js
new file mode 100644
index 000000000..a5d0a564b
--- /dev/null
+++ b/Sprint-2/interpret/invert.test.js
@@ -0,0 +1,10 @@
+const invert = require("./invert");
+
+test("returns an object with the key and value swapped when given a single key-value pair", ()=>{
+  expect(invert({a:1})).toEqual({'1':'a'})
+});
+
+test("returns an object with all keys and values swapped for multiple key-value pairs",()=>{
+
+    expect(invert({a:1, b:2})).toEqual({'1':'a','2':'b'})
+});
\ No newline at end of file

From 4eae7cb5810bb4830621d6d52cbb99734dc85ead Mon Sep 17 00:00:00 2001
From: Arunkumar Akilan <arunkumarakilanarun@gmail.com>
Date: Tue, 17 Mar 2026 08:44:16 +0000
Subject: [PATCH 15/15] fix: remove unintended Sprint-1 changes from Sprint-2
 PR

---
 Sprint-1/implement/dedupe.js |  2 +-
 package.json                 | 24 ++++++++++++++++++++++++
 2 files changed, 25 insertions(+), 1 deletion(-)
 create mode 100644 package.json

diff --git a/Sprint-1/implement/dedupe.js b/Sprint-1/implement/dedupe.js
index b19b591e3..e15439a83 100644
--- a/Sprint-1/implement/dedupe.js
+++ b/Sprint-1/implement/dedupe.js
@@ -8,7 +8,7 @@ function dedupe(list) {
   {
     if(!result.includes(item))
     {
-        result.push(item)
+        result.push(item);
     }
     }
     return result;
diff --git a/package.json b/package.json
new file mode 100644
index 000000000..40fec1762
--- /dev/null
+++ b/package.json
@@ -0,0 +1,24 @@
+{
+  "name": "module-data-groups",
+  "version": "1.0.0",
+  "description": "Like learning a musical instrument, programming requires daily practice.",
+  "main": "index.js",
+  "scripts": {
+    "test": "echo \"Error: no test specified\" && exit 1"
+  },
+  "repository": {
+    "type": "git",
+    "url": "git+https://github.com/arunkumarakilan/Module-Data-Groups.git"
+  },
+  "keywords": [],
+  "author": "",
+  "license": "ISC",
+  "type": "commonjs",
+  "bugs": {
+    "url": "https://github.com/arunkumarakilan/Module-Data-Groups/issues"
+  },
+  "homepage": "https://github.com/arunkumarakilan/Module-Data-Groups#readme",
+  "devDependencies": {
+    "jest": "^30.2.0"
+  }
+}