From bd846e8a910bec155d542667f1133ae272acd196 Mon Sep 17 00:00:00 2001
From: Alex Jamshidi <alexjamshidi@Alexs-MacBook-Air.local>
Date: Wed, 13 May 2026 00:58:36 +0100
Subject: [PATCH 01/14] debugged address.js

---
 Sprint-2/debug/address.js | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/Sprint-2/debug/address.js b/Sprint-2/debug/address.js
index 940a6af83..54aa0c02a 100644
--- a/Sprint-2/debug/address.js
+++ b/Sprint-2/debug/address.js
@@ -1,4 +1,5 @@
 // Predict and explain first...
+// This will fail because to parse from an object requires a key, not an index value
 
 // This code should log out the houseNumber from the address object
 // but it isn't working...
@@ -12,4 +13,4 @@ const address = {
   postcode: "XYZ 123",
 };
 
-console.log(`My house number is ${address[0]}`);
+console.log(`My house number is ${address.street}, ${address.city}, ${address.country}, ${address.postcode}`);

From dc61f913aa7f3bc316dd79ebdaf8904424e4ca1f Mon Sep 17 00:00:00 2001
From: Alex Jamshidi <alexjamshidi@Alexs-MacBook-Air.local>
Date: Wed, 13 May 2026 01:04:01 +0100
Subject: [PATCH 02/14] debugged author.js

---
 Sprint-2/debug/author.js | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/Sprint-2/debug/author.js b/Sprint-2/debug/author.js
index 8c2125977..eb6208ac2 100644
--- a/Sprint-2/debug/author.js
+++ b/Sprint-2/debug/author.js
@@ -1,4 +1,5 @@
 // Predict and explain first...
+// the for loop it the syntax for an array, I'm not sure it will work with an object
 
 // 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
@@ -11,6 +12,6 @@ const author = {
   alive: true,
 };
 
-for (const value of author) {
+for (const value of Object.values(author)) {
   console.log(value);
 }

From 5761063572afc6425739d2a1be45a58d6f94472f Mon Sep 17 00:00:00 2001
From: Alex Jamshidi <alexjamshidi@Alexs-MacBook-Air.local>
Date: Wed, 13 May 2026 01:12:46 +0100
Subject: [PATCH 03/14] debugged recipe.js

---
 Sprint-2/debug/recipe.js | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/Sprint-2/debug/recipe.js b/Sprint-2/debug/recipe.js
index 6cbdd22cd..eb835edea 100644
--- a/Sprint-2/debug/recipe.js
+++ b/Sprint-2/debug/recipe.js
@@ -1,4 +1,6 @@
 // Predict and explain first...
+// the title and serves looks like it would work, the ingredients list is just calling the recipe object
+// that won't list any values and may return an error or undefined.
 
 // This program should log out the title, how many it serves and the ingredients.
 // Each ingredient should be logged on a new line
@@ -11,5 +13,5 @@ const recipe = {
 };
 
 console.log(`${recipe.title} serves ${recipe.serves}
-  ingredients:
-${recipe}`);
+ingredients:
+${recipe.ingredients.join("\n")}`);

From 3ff26b115a9b2322c81baa4b1fc115c376e947b7 Mon Sep 17 00:00:00 2001
From: Alex Jamshidi <alexjamshidi@Alexs-MacBook-Air.local>
Date: Wed, 13 May 2026 01:32:08 +0100
Subject: [PATCH 04/14] contains.test.js tests written

---
 Sprint-2/implement/contains.js      |  4 +++-
 Sprint-2/implement/contains.test.js | 24 ++++++++++++++++++++++--
 2 files changed, 25 insertions(+), 3 deletions(-)

diff --git a/Sprint-2/implement/contains.js b/Sprint-2/implement/contains.js
index cd779308a..3de7795ed 100644
--- a/Sprint-2/implement/contains.js
+++ b/Sprint-2/implement/contains.js
@@ -1,3 +1,5 @@
-function contains() {}
+function contains() {
+    return true
+}
 
 module.exports = contains;
diff --git a/Sprint-2/implement/contains.test.js b/Sprint-2/implement/contains.test.js
index 326bdb1f2..3fc401aca 100644
--- a/Sprint-2/implement/contains.test.js
+++ b/Sprint-2/implement/contains.test.js
@@ -12,24 +12,44 @@ as the object doesn't contains a key of 'c'
 */
 
 // Acceptance criteria:
-
 // Given a contains function
 // When passed an object and a property name
 // Then it should return true if the object contains the property, false otherwise
 
+describe("contains", () =>{
 // Given an empty object
 // When passed to contains
 // Then it should return false
-test.todo("contains on empty object returns false");
+it("contains on empty object returns false", () => {
+    const object = {};
+    const property = 'a'
+    expect(contains(object, property)).toEqual(false)
+});
 
 // Given an object with properties
 // When passed to contains with an existing property name
 // Then it should return true
+it("object contains property returns true", () => {
+    const object = {a: 1, b: 2};
+    const property = 'a'
+    expect(contains(object, property)).toEqual(true)
+});
 
 // Given an object with properties
 // When passed to contains with a non-existent property name
 // Then it should return false
+it("object does not contain property returns false", () => {
+    const object = {a: 1, b: 2};
+    const property = 'c'
+    expect(contains(object, property)).toEqual(false)
+});
 
 // Given invalid parameters like an array
 // When passed to contains
 // Then it should return false or throw an error
+it("given invalid parameter (an array) returns false or throws an error", () => {
+    const object = [];
+    const property = [];
+    expect(contains(object, property)).toEqual(false)
+});
+});
\ No newline at end of file

From 59b776367b8c97540efcd1c32d89e6519f4e4d3a Mon Sep 17 00:00:00 2001
From: Alex Jamshidi <alexjamshidi@Alexs-MacBook-Air.local>
Date: Wed, 13 May 2026 01:43:38 +0100
Subject: [PATCH 05/14] added solution to contains.js

---
 Sprint-2/implement/contains.js | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/Sprint-2/implement/contains.js b/Sprint-2/implement/contains.js
index 3de7795ed..749dc3269 100644
--- a/Sprint-2/implement/contains.js
+++ b/Sprint-2/implement/contains.js
@@ -1,5 +1,8 @@
-function contains() {
-    return true
+function contains(object, property) {
+    if (typeof object !== 'object' || Array.isArray(object)) {return false;}
+    if (typeof property !== 'string') {return false;}
+
+    return Object.hasOwn(object, property)
 }
 
 module.exports = contains;

From 40a2e863dec3f68a6ab70b6c62586466a18cad16 Mon Sep 17 00:00:00 2001
From: Alex Jamshidi <alexjamshidi@Alexs-MacBook-Air.local>
Date: Wed, 13 May 2026 01:51:00 +0100
Subject: [PATCH 06/14] written test for lookup.test.js

---
 Sprint-2/implement/contains.test.js | 2 +-
 Sprint-2/implement/lookup.js        | 2 +-
 Sprint-2/implement/lookup.test.js   | 7 ++++++-
 3 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/Sprint-2/implement/contains.test.js b/Sprint-2/implement/contains.test.js
index 3fc401aca..4ae4376d0 100644
--- a/Sprint-2/implement/contains.test.js
+++ b/Sprint-2/implement/contains.test.js
@@ -16,7 +16,7 @@ as the object doesn't contains a key of 'c'
 // When passed an object and a property name
 // Then it should return true if the object contains the property, false otherwise
 
-describe("contains", () =>{
+describe("contains", () => {
 // Given an empty object
 // When passed to contains
 // Then it should return false
diff --git a/Sprint-2/implement/lookup.js b/Sprint-2/implement/lookup.js
index a6746e07f..7864587e2 100644
--- a/Sprint-2/implement/lookup.js
+++ b/Sprint-2/implement/lookup.js
@@ -1,5 +1,5 @@
 function createLookup() {
-  // implementation here
+  return {'US': 'USD', 'CA': 'CAD', 'UK': 'GBP'}
 }
 
 module.exports = createLookup;
diff --git a/Sprint-2/implement/lookup.test.js b/Sprint-2/implement/lookup.test.js
index 547e06c5a..8852123ed 100644
--- a/Sprint-2/implement/lookup.test.js
+++ b/Sprint-2/implement/lookup.test.js
@@ -1,6 +1,11 @@
 const createLookup = require("./lookup.js");
 
-test.todo("creates a country currency code lookup for multiple codes");
+describe("createLookup", () => {
+  it("creates a country currency code lookup for multiple codes", () => {
+    const arrayOfArrays = [['US', 'USD'], ['CA', 'CAD'], ['UK', 'GBP']]
+    expect(createLookup(arrayOfArrays)).toEqual( {'US': 'USD', 'CA': 'CAD', 'UK': 'GBP'})
+ })
+});
 
 /*
 

From 556787567fef6c47edefa3c4c143d2cb7d201202 Mon Sep 17 00:00:00 2001
From: Alex Jamshidi <alexjamshidi@Alexs-MacBook-Air.local>
Date: Wed, 13 May 2026 01:58:28 +0100
Subject: [PATCH 07/14] added solution to lookup.js

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

diff --git a/Sprint-2/implement/lookup.js b/Sprint-2/implement/lookup.js
index 7864587e2..ec1a751f6 100644
--- a/Sprint-2/implement/lookup.js
+++ b/Sprint-2/implement/lookup.js
@@ -1,5 +1,9 @@
-function createLookup() {
-  return {'US': 'USD', 'CA': 'CAD', 'UK': 'GBP'}
+function createLookup(arrayOfArrays) {
+  const lookup = {}
+  for (array of arrayOfArrays) {
+    lookup[array[0]] = array[1];
+  }
+  return lookup
 }
 
 module.exports = createLookup;

From f928482bcd57d69823d7c02c72b6a02133a22c63 Mon Sep 17 00:00:00 2001
From: Alex Jamshidi <alexjamshidi@Alexs-MacBook-Air.local>
Date: Wed, 13 May 2026 02:36:23 +0100
Subject: [PATCH 08/14] added solution to tally.js

---
 Sprint-2/implement/tally.js      | 11 ++++++++++-
 Sprint-2/implement/tally.test.js | 18 +++++++++++++++++-
 2 files changed, 27 insertions(+), 2 deletions(-)

diff --git a/Sprint-2/implement/tally.js b/Sprint-2/implement/tally.js
index f47321812..2ce89ada6 100644
--- a/Sprint-2/implement/tally.js
+++ b/Sprint-2/implement/tally.js
@@ -1,3 +1,12 @@
-function tally() {}
+function tally(array) {
+    if (!Array.isArray(array)) {throw new Error("Invalid array");}
+    tally = {}
+    array.forEach((item) =>{
+        if (item in tally) {tally[item] += 1}
+        else tally[item] = 1;
+    })
+    return tally
+}
 
 module.exports = tally;
+
diff --git a/Sprint-2/implement/tally.test.js b/Sprint-2/implement/tally.test.js
index 2ceffa8dd..406b004e5 100644
--- a/Sprint-2/implement/tally.test.js
+++ b/Sprint-2/implement/tally.test.js
@@ -20,15 +20,31 @@ const tally = require("./tally.js");
 // When passed an array of items
 // Then it should return an object containing the count for each unique item
 
+describe("tally", () => {
 // Given an empty array
 // When passed to tally
 // Then it should return an empty object
-test.todo("tally on an empty array returns an empty object");
+it("tally on an empty array returns an empty object", () => {
+    const array = [];
+    expect(tally(array)).toEqual({})
+});
+
 
 // Given an array with duplicate items
 // When passed to tally
 // Then it should return counts for each unique item
+it("tally returns counts for each unique item", () => {
+    const array = ['a', 'a', 'b', 'c'];
+    expect(tally(array)).toEqual({ a : 2, b: 1, c: 1 })
+});
+
 
 // Given an invalid input like a string
 // When passed to tally
 // Then it should throw an error
+it("tally on an empty array returns an empty object", () => {
+    const array = "string";
+    expect(() => {tally(array);}).toThrow("Invalid array")
+});
+});
+

From 3b915141b8bc25f34ccb9fb59a73a90c7bd17a8e Mon Sep 17 00:00:00 2001
From: Alex Jamshidi <alexjamshidi@Alexs-MacBook-Air.local>
Date: Wed, 13 May 2026 03:38:45 +0100
Subject: [PATCH 09/14] completed querystring.js

---
 Sprint-2/implement/querystring.js      | 28 +++++++++++++++++++++++++-
 Sprint-2/implement/querystring.test.js |  2 ++
 2 files changed, 29 insertions(+), 1 deletion(-)

diff --git a/Sprint-2/implement/querystring.js b/Sprint-2/implement/querystring.js
index 45ec4e5f3..9f7827a7b 100644
--- a/Sprint-2/implement/querystring.js
+++ b/Sprint-2/implement/querystring.js
@@ -3,14 +3,40 @@ function parseQueryString(queryString) {
   if (queryString.length === 0) {
     return queryParams;
   }
+
+  // Adds percentage-encoded characters
+  queryString = changePEC(queryString)
+
+  // Replaces + with space
+  queryString = queryString.replaceAll("+", " ")
+  
   const keyValuePairs = queryString.split("&");
 
   for (const pair of keyValuePairs) {
-    const [key, value] = pair.split("=");
+    if (pair !== "") {
+    let index = pair.indexOf("=")
+    if (!pair.includes("=")) {index = pair.length}
+    const [key, value] = [pair.slice(0, index), pair.slice(index + 1)]
     queryParams[key] = value;
+    }
+    else {};
   }
 
   return queryParams;
 }
 
+// this function below can have the object PEC expanded to include all percentage-encoded characters
+// currently without adding this database, an unknown PEC could cause the code to get stuck in an infinite loop
+
+function changePEC(string) {
+  const PEC = {"%24": "$", "%2F": "/"}
+  while (string.includes("%")) {
+    const index = string.indexOf("%");
+    const code = string.slice(index, index + 3);
+    if (PEC[code]) {string = string.replace(code, PEC[code]);}
+    else {break;}
+  }
+  return string
+}
+
 module.exports = parseQueryString;
diff --git a/Sprint-2/implement/querystring.test.js b/Sprint-2/implement/querystring.test.js
index 328b8df61..a3b3605a2 100644
--- a/Sprint-2/implement/querystring.test.js
+++ b/Sprint-2/implement/querystring.test.js
@@ -40,9 +40,11 @@ test("should replace '+' by ' '", () => {
 // Stretch exercise: Handling query strings that contain identical keys
 
 // Delete this test if you are not working on this optional case
+/*
 test("should store values of a key in an array when the key has 2 or more values", () => {
   expect(parseQueryString("key=value1&key=value2&key=value3&foo=bar")).toEqual({
     key: ["value1", "value2", "value3"],
     foo: "bar",
   });
 });
+*/
\ No newline at end of file

From 352aef984c37e7048a4d4fbb33e48c28c7967ba4 Mon Sep 17 00:00:00 2001
From: Alex Jamshidi <alexjamshidi@Alexs-MacBook-Air.local>
Date: Wed, 13 May 2026 03:59:14 +0100
Subject: [PATCH 10/14] completed invert.js

---
 Sprint-2/interpret/invert.js      | 16 ++++++++++++++--
 Sprint-2/interpret/invert.test.js | 14 ++++++++++++++
 2 files changed, 28 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..27ac09bdd 100644
--- a/Sprint-2/interpret/invert.js
+++ b/Sprint-2/interpret/invert.js
@@ -6,24 +6,36 @@
 
 // E.g. invert({x : 10, y : 20}), target output: {"10": "x", "20": "y"}
 
+invert({ a: 1, b: 2 })
+
 function invert(obj) {
   const invertedObj = {};
 
   for (const [key, value] of Object.entries(obj)) {
-    invertedObj.key = value;
+    invertedObj[value] = key
   }
-
+  console.log(invertedObj)
   return invertedObj;
 }
 
+
 // 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: 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?
+// It turns the object into an array of arrays
+// It's needed so the for..of loop can access the key:value pairs
 
 // d) Explain why the current return value is different from the target output
+// invertedObj.key = value;
+// this line of code sets the key to "key"
+// even if that worked as intended, the key and value haven't been swapped
 
 // e) Fix the implementation of invert (and write tests to prove it's fixed!)
+module.exports = invert;
\ No newline at end of file
diff --git a/Sprint-2/interpret/invert.test.js b/Sprint-2/interpret/invert.test.js
new file mode 100644
index 000000000..5e59c375e
--- /dev/null
+++ b/Sprint-2/interpret/invert.test.js
@@ -0,0 +1,14 @@
+const invert = require("./invert.js");
+
+describe("invert", () => {
+it("object returns inverted object", () => {
+    
+// a) What is the current return value when invert is called with { a : 1 }
+    let object = { a : 1 };    
+    expect(invert(object)).toEqual({1: "a"})
+
+// b) What is the current return value when invert is called with { a: 1, b: 2 }
+    object = { a: 1, b: 2 }; 
+    expect(invert(object)).toEqual({1: "a", 2: "b"})
+});
+});
\ No newline at end of file

From 66a45541cf3abf12b5f55fd93333d53d1ade14af Mon Sep 17 00:00:00 2001
From: Alex Jamshidi <alexjamshidi@Alexs-MacBook-Air.local>
Date: Wed, 13 May 2026 03:59:52 +0100
Subject: [PATCH 11/14] changes added that weren't saved to last commit

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

diff --git a/Sprint-2/interpret/invert.js b/Sprint-2/interpret/invert.js
index 27ac09bdd..0161fc9b9 100644
--- a/Sprint-2/interpret/invert.js
+++ b/Sprint-2/interpret/invert.js
@@ -26,7 +26,7 @@ function invert(obj) {
 // { key: 2 }
 
 // c) What is the target return value when invert is called with {a : 1, b: 2}
-// {"1": "a", "2": "b"}
+// {1: a, 2: b}
 
 // c) What does Object.entries return? Why is it needed in this program?
 // It turns the object into an array of arrays

From 6cb0fe27ba0d816f05de1fce84e68ef19bf8527a Mon Sep 17 00:00:00 2001
From: Alex Jamshidi <alexjamshidi@Alexs-MacBook-Air.local>
Date: Wed, 13 May 2026 17:28:58 +0100
Subject: [PATCH 12/14] added tests to ensure contains does not allow arrays
 and null, fixed lookup

---
 Sprint-2/debug/address.js              |  4 +-
 Sprint-2/implement/contains.js         | 10 ++--
 Sprint-2/implement/contains.test.js    | 75 ++++++++++++++------------
 Sprint-2/implement/lookup.js           |  6 +--
 Sprint-2/implement/lookup.test.js      | 14 +++--
 Sprint-2/implement/querystring.js      | 29 +++++-----
 Sprint-2/implement/querystring.test.js |  4 +-
 Sprint-2/implement/tally.js            | 18 ++++---
 Sprint-2/implement/tally.test.js       | 47 ++++++++--------
 Sprint-2/interpret/invert.js           |  9 ++--
 Sprint-2/interpret/invert.test.js      | 17 +++---
 11 files changed, 129 insertions(+), 104 deletions(-)

diff --git a/Sprint-2/debug/address.js b/Sprint-2/debug/address.js
index 54aa0c02a..22b116672 100644
--- a/Sprint-2/debug/address.js
+++ b/Sprint-2/debug/address.js
@@ -13,4 +13,6 @@ const address = {
   postcode: "XYZ 123",
 };
 
-console.log(`My house number is ${address.street}, ${address.city}, ${address.country}, ${address.postcode}`);
+console.log(
+  `My house number is ${address.houseNumber}, ${address.street}, ${address.city}, ${address.country}, ${address.postcode}`
+);
diff --git a/Sprint-2/implement/contains.js b/Sprint-2/implement/contains.js
index 749dc3269..f837505ae 100644
--- a/Sprint-2/implement/contains.js
+++ b/Sprint-2/implement/contains.js
@@ -1,8 +1,12 @@
 function contains(object, property) {
-    if (typeof object !== 'object' || Array.isArray(object)) {return false;}
-    if (typeof property !== 'string') {return false;}
+  if (typeof object !== "object" || !object || Array.isArray(object)) {
+    return false;
+  }
+  if (typeof property !== "string" || !object) {
+    return false;
+  }
 
-    return Object.hasOwn(object, property)
+  return Object.hasOwn(object, property);
 }
 
 module.exports = contains;
diff --git a/Sprint-2/implement/contains.test.js b/Sprint-2/implement/contains.test.js
index 4ae4376d0..6d5f04426 100644
--- a/Sprint-2/implement/contains.test.js
+++ b/Sprint-2/implement/contains.test.js
@@ -17,39 +17,46 @@ as the object doesn't contains a key of 'c'
 // Then it should return true if the object contains the property, false otherwise
 
 describe("contains", () => {
-// Given an empty object
-// When passed to contains
-// Then it should return false
-it("contains on empty object returns false", () => {
+  // Given an empty object
+  // When passed to contains
+  // Then it should return false
+  it("contains on empty object returns false", () => {
     const object = {};
-    const property = 'a'
-    expect(contains(object, property)).toEqual(false)
+    const property = "a";
+    expect(contains(object, property)).toEqual(false);
+  });
+
+  // Given an object with properties
+  // When passed to contains with an existing property name
+  // Then it should return true
+  it("object contains property returns true", () => {
+    const object = { a: 1, b: 2 };
+    const property = "a";
+    expect(contains(object, property)).toEqual(true);
+  });
+
+  // Given an object with properties
+  // When passed to contains with a non-existent property name
+  // Then it should return false
+  it("object does not contain property returns false", () => {
+    const object = { a: 1, b: 2 };
+    const property = "c";
+    expect(contains(object, property)).toEqual(false);
+  });
+
+  // Given invalid parameters like an array
+  // When passed to contains
+  // Then it should return false or throw an error
+  it("given invalid parameter (an array) returns false or throws an error", () => {
+    expect(contains([], [])).toEqual(false);
+    expect(contains(["a", 1], "a")).toEqual(false);
+    expect(contains({ a: 1, b: 2 }, ["a"])).toEqual(false);
+    expect(contains(["a", 1], ["a"])).toEqual(false);
+  });
+
+  it("given null returns false", () => {
+    expect(contains(null, "a")).toEqual(false);
+    expect(contains({ a: 1, b: 2 }, null)).toEqual(false);
+    expect(contains(null, null)).toEqual(false);
+  });
 });
-
-// Given an object with properties
-// When passed to contains with an existing property name
-// Then it should return true
-it("object contains property returns true", () => {
-    const object = {a: 1, b: 2};
-    const property = 'a'
-    expect(contains(object, property)).toEqual(true)
-});
-
-// Given an object with properties
-// When passed to contains with a non-existent property name
-// Then it should return false
-it("object does not contain property returns false", () => {
-    const object = {a: 1, b: 2};
-    const property = 'c'
-    expect(contains(object, property)).toEqual(false)
-});
-
-// Given invalid parameters like an array
-// When passed to contains
-// Then it should return false or throw an error
-it("given invalid parameter (an array) returns false or throws an error", () => {
-    const object = [];
-    const property = [];
-    expect(contains(object, property)).toEqual(false)
-});
-});
\ No newline at end of file
diff --git a/Sprint-2/implement/lookup.js b/Sprint-2/implement/lookup.js
index ec1a751f6..7d4439d0f 100644
--- a/Sprint-2/implement/lookup.js
+++ b/Sprint-2/implement/lookup.js
@@ -1,9 +1,9 @@
 function createLookup(arrayOfArrays) {
-  const lookup = {}
-  for (array of arrayOfArrays) {
+  const lookup = {};
+  for (const array of arrayOfArrays) {
     lookup[array[0]] = array[1];
   }
-  return lookup
+  return lookup;
 }
 
 module.exports = createLookup;
diff --git a/Sprint-2/implement/lookup.test.js b/Sprint-2/implement/lookup.test.js
index 8852123ed..8ee5bf26f 100644
--- a/Sprint-2/implement/lookup.test.js
+++ b/Sprint-2/implement/lookup.test.js
@@ -2,9 +2,17 @@ const createLookup = require("./lookup.js");
 
 describe("createLookup", () => {
   it("creates a country currency code lookup for multiple codes", () => {
-    const arrayOfArrays = [['US', 'USD'], ['CA', 'CAD'], ['UK', 'GBP']]
-    expect(createLookup(arrayOfArrays)).toEqual( {'US': 'USD', 'CA': 'CAD', 'UK': 'GBP'})
- })
+    const arrayOfArrays = [
+      ["US", "USD"],
+      ["CA", "CAD"],
+      ["UK", "GBP"],
+    ];
+    expect(createLookup(arrayOfArrays)).toEqual({
+      US: "USD",
+      CA: "CAD",
+      UK: "GBP",
+    });
+  });
 });
 
 /*
diff --git a/Sprint-2/implement/querystring.js b/Sprint-2/implement/querystring.js
index 9f7827a7b..632407834 100644
--- a/Sprint-2/implement/querystring.js
+++ b/Sprint-2/implement/querystring.js
@@ -5,21 +5,23 @@ function parseQueryString(queryString) {
   }
 
   // Adds percentage-encoded characters
-  queryString = changePEC(queryString)
+  queryString = changePEC(queryString);
 
   // Replaces + with space
-  queryString = queryString.replaceAll("+", " ")
-  
+  queryString = queryString.replaceAll("+", " ");
+
   const keyValuePairs = queryString.split("&");
 
   for (const pair of keyValuePairs) {
     if (pair !== "") {
-    let index = pair.indexOf("=")
-    if (!pair.includes("=")) {index = pair.length}
-    const [key, value] = [pair.slice(0, index), pair.slice(index + 1)]
-    queryParams[key] = value;
+      let index = pair.indexOf("=");
+      if (!pair.includes("=")) {
+        index = pair.length;
+      }
+      const [key, value] = [pair.slice(0, index), pair.slice(index + 1)];
+      queryParams[key] = value;
+    } else {
     }
-    else {};
   }
 
   return queryParams;
@@ -29,14 +31,17 @@ function parseQueryString(queryString) {
 // currently without adding this database, an unknown PEC could cause the code to get stuck in an infinite loop
 
 function changePEC(string) {
-  const PEC = {"%24": "$", "%2F": "/"}
+  const PEC = { "%24": "$", "%2F": "/" };
   while (string.includes("%")) {
     const index = string.indexOf("%");
     const code = string.slice(index, index + 3);
-    if (PEC[code]) {string = string.replace(code, PEC[code]);}
-    else {break;}
+    if (PEC[code]) {
+      string = string.replace(code, PEC[code]);
+    } else {
+      break;
+    }
   }
-  return string
+  return string;
 }
 
 module.exports = parseQueryString;
diff --git a/Sprint-2/implement/querystring.test.js b/Sprint-2/implement/querystring.test.js
index a3b3605a2..c992e40f5 100644
--- a/Sprint-2/implement/querystring.test.js
+++ b/Sprint-2/implement/querystring.test.js
@@ -3,7 +3,7 @@
 // Below are some test cases the implementation doesn't handle well.
 // Fix the implementation for these tests, and try to think of as many other edge cases as possible - write tests and fix those too.
 
-const parseQueryString = require("./querystring.js")
+const parseQueryString = require("./querystring.js");
 
 test("should parse values containing '='", () => {
   expect(parseQueryString("equation=a=b-2")).toEqual({
@@ -47,4 +47,4 @@ test("should store values of a key in an array when the key has 2 or more values
     foo: "bar",
   });
 });
-*/
\ No newline at end of file
+*/
diff --git a/Sprint-2/implement/tally.js b/Sprint-2/implement/tally.js
index 2ce89ada6..82a3d35ab 100644
--- a/Sprint-2/implement/tally.js
+++ b/Sprint-2/implement/tally.js
@@ -1,12 +1,14 @@
 function tally(array) {
-    if (!Array.isArray(array)) {throw new Error("Invalid array");}
-    tally = {}
-    array.forEach((item) =>{
-        if (item in tally) {tally[item] += 1}
-        else tally[item] = 1;
-    })
-    return tally
+  if (!Array.isArray(array)) {
+    throw new Error("Invalid array");
+  }
+  tally = {};
+  array.forEach((item) => {
+    if (item in tally) {
+      tally[item] += 1;
+    } else tally[item] = 1;
+  });
+  return tally;
 }
 
 module.exports = tally;
-
diff --git a/Sprint-2/implement/tally.test.js b/Sprint-2/implement/tally.test.js
index 406b004e5..c9d5167fc 100644
--- a/Sprint-2/implement/tally.test.js
+++ b/Sprint-2/implement/tally.test.js
@@ -21,30 +21,29 @@ const tally = require("./tally.js");
 // Then it should return an object containing the count for each unique item
 
 describe("tally", () => {
-// Given an empty array
-// When passed to tally
-// Then it should return an empty object
-it("tally on an empty array returns an empty object", () => {
+  // Given an empty array
+  // When passed to tally
+  // Then it should return an empty object
+  it("tally on an empty array returns an empty object", () => {
     const array = [];
-    expect(tally(array)).toEqual({})
-});
-
-
-// Given an array with duplicate items
-// When passed to tally
-// Then it should return counts for each unique item
-it("tally returns counts for each unique item", () => {
-    const array = ['a', 'a', 'b', 'c'];
-    expect(tally(array)).toEqual({ a : 2, b: 1, c: 1 })
-});
-
-
-// Given an invalid input like a string
-// When passed to tally
-// Then it should throw an error
-it("tally on an empty array returns an empty object", () => {
+    expect(tally(array)).toEqual({});
+  });
+
+  // Given an array with duplicate items
+  // When passed to tally
+  // Then it should return counts for each unique item
+  it("tally returns counts for each unique item", () => {
+    const array = ["a", "a", "b", "c"];
+    expect(tally(array)).toEqual({ a: 2, b: 1, c: 1 });
+  });
+
+  // Given an invalid input like a string
+  // When passed to tally
+  // Then it should throw an error
+  it("tally on an empty array returns an empty object", () => {
     const array = "string";
-    expect(() => {tally(array);}).toThrow("Invalid array")
+    expect(() => {
+      tally(array);
+    }).toThrow("Invalid array");
+  });
 });
-});
-
diff --git a/Sprint-2/interpret/invert.js b/Sprint-2/interpret/invert.js
index 0161fc9b9..49a737a4a 100644
--- a/Sprint-2/interpret/invert.js
+++ b/Sprint-2/interpret/invert.js
@@ -6,19 +6,18 @@
 
 // E.g. invert({x : 10, y : 20}), target output: {"10": "x", "20": "y"}
 
-invert({ a: 1, b: 2 })
+invert({ a: 1, b: 2 });
 
 function invert(obj) {
   const invertedObj = {};
 
   for (const [key, value] of Object.entries(obj)) {
-    invertedObj[value] = key
+    invertedObj[value] = key;
   }
-  console.log(invertedObj)
+  console.log(invertedObj);
   return invertedObj;
 }
 
-
 // a) What is the current return value when invert is called with { a : 1 }
 // { key: 1 }
 
@@ -38,4 +37,4 @@ function invert(obj) {
 // even if that worked as intended, the key and value haven't been swapped
 
 // e) Fix the implementation of invert (and write tests to prove it's fixed!)
-module.exports = invert;
\ No newline at end of file
+module.exports = invert;
diff --git a/Sprint-2/interpret/invert.test.js b/Sprint-2/interpret/invert.test.js
index 5e59c375e..6343dd396 100644
--- a/Sprint-2/interpret/invert.test.js
+++ b/Sprint-2/interpret/invert.test.js
@@ -1,14 +1,13 @@
 const invert = require("./invert.js");
 
 describe("invert", () => {
-it("object returns inverted object", () => {
-    
-// a) What is the current return value when invert is called with { a : 1 }
-    let object = { a : 1 };    
-    expect(invert(object)).toEqual({1: "a"})
+  it("object returns inverted object", () => {
+    // a) What is the current return value when invert is called with { a : 1 }
+    let object = { a: 1 };
+    expect(invert(object)).toEqual({ 1: "a" });
 
-// b) What is the current return value when invert is called with { a: 1, b: 2 }
-    object = { a: 1, b: 2 }; 
-    expect(invert(object)).toEqual({1: "a", 2: "b"})
+    // b) What is the current return value when invert is called with { a: 1, b: 2 }
+    object = { a: 1, b: 2 };
+    expect(invert(object)).toEqual({ 1: "a", 2: "b" });
+  });
 });
-});
\ No newline at end of file

From 193230c734c46c12b24bb300ac6c9e969222c6cb Mon Sep 17 00:00:00 2001
From: Alex Jamshidi <alexjamshidi@Alexs-MacBook-Air.local>
Date: Wed, 13 May 2026 17:30:51 +0100
Subject: [PATCH 13/14] remove erroneous 'else'

---
 Sprint-2/implement/querystring.js | 1 -
 1 file changed, 1 deletion(-)

diff --git a/Sprint-2/implement/querystring.js b/Sprint-2/implement/querystring.js
index 632407834..1e0cac42b 100644
--- a/Sprint-2/implement/querystring.js
+++ b/Sprint-2/implement/querystring.js
@@ -20,7 +20,6 @@ function parseQueryString(queryString) {
       }
       const [key, value] = [pair.slice(0, index), pair.slice(index + 1)];
       queryParams[key] = value;
-    } else {
     }
   }
 

From 8427bfd3f636fc598748f6ddea4caf1509e8d28b Mon Sep 17 00:00:00 2001
From: Alex Jamshidi <alexjamshidi@Alexs-MacBook-Air.local>
Date: Wed, 13 May 2026 17:32:55 +0100
Subject: [PATCH 14/14] updated code to use decodeURIcomponent

---
 Sprint-2/implement/querystring.js | 19 +------------------
 1 file changed, 1 insertion(+), 18 deletions(-)

diff --git a/Sprint-2/implement/querystring.js b/Sprint-2/implement/querystring.js
index 1e0cac42b..1c0491e34 100644
--- a/Sprint-2/implement/querystring.js
+++ b/Sprint-2/implement/querystring.js
@@ -5,7 +5,7 @@ function parseQueryString(queryString) {
   }
 
   // Adds percentage-encoded characters
-  queryString = changePEC(queryString);
+  queryString = decodeURIComponent(queryString);
 
   // Replaces + with space
   queryString = queryString.replaceAll("+", " ");
@@ -26,21 +26,4 @@ function parseQueryString(queryString) {
   return queryParams;
 }
 
-// this function below can have the object PEC expanded to include all percentage-encoded characters
-// currently without adding this database, an unknown PEC could cause the code to get stuck in an infinite loop
-
-function changePEC(string) {
-  const PEC = { "%24": "$", "%2F": "/" };
-  while (string.includes("%")) {
-    const index = string.indexOf("%");
-    const code = string.slice(index, index + 3);
-    if (PEC[code]) {
-      string = string.replace(code, PEC[code]);
-    } else {
-      break;
-    }
-  }
-  return string;
-}
-
 module.exports = parseQueryString;