From b88166f3cd73f3199ec4630b1f284d0329165e0d Mon Sep 17 00:00:00 2001
From: Precious Moses <mosesjeffrey74@gmail.com>
Date: Thu, 5 Nov 2026 19:45:12 +0000
Subject: [PATCH 01/52] Fix console log to correctly display house number 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..36d2f865d 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 7158a9b1ffd2bbb156d52fe7324566b2500aba2d Mon Sep 17 00:00:00 2001
From: Precious Moses <mosesjeffrey74@gmail.com>
Date: Thu, 5 Nov 2026 19:46:21 +0000
Subject: [PATCH 02/52] Remove commented-out code and explanations from
 address.js

---
 Sprint-2/debug/address.js | 6 ------
 1 file changed, 6 deletions(-)

diff --git a/Sprint-2/debug/address.js b/Sprint-2/debug/address.js
index 36d2f865d..0886a5278 100644
--- a/Sprint-2/debug/address.js
+++ b/Sprint-2/debug/address.js
@@ -1,9 +1,3 @@
-// Predict and explain first...
-
-// This code should log out the houseNumber from the address object
-// but it isn't working...
-// Fix anything that isn't working
-
 const address = {
   houseNumber: 42,
   street: "Imaginary Road",

From 16a2b1a4eb1c911caf12666ce3e7f43bb2d9b8ae Mon Sep 17 00:00:00 2001
From: Precious Moses <mosesjeffrey74@gmail.com>
Date: Thu, 5 Nov 2026 19:58:04 +0000
Subject: [PATCH 03/52] Add explanation for for...of loop issue in author.js

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

diff --git a/Sprint-2/debug/author.js b/Sprint-2/debug/author.js
index 8c2125977..2ba2284a9 100644
--- a/Sprint-2/debug/author.js
+++ b/Sprint-2/debug/author.js
@@ -3,6 +3,10 @@
 // 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
 
+// explanation:
+// The code could not be executed because the for...of loop could not access object "author".
+// for...loops are used in arrays, strings or with certain array methods.
+
 const author = {
   firstName: "Zadie",
   lastName: "Smith",

From b124b4dc19d13aa8b3fcb55740e7748faa15444f Mon Sep 17 00:00:00 2001
From: Precious Moses <mosesjeffrey74@gmail.com>
Date: Thu, 5 Nov 2026 19:59:36 +0000
Subject: [PATCH 04/52] Fix for...of loop to correctly iterate over author
 object properties

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

diff --git a/Sprint-2/debug/author.js b/Sprint-2/debug/author.js
index 2ba2284a9..63eec98c1 100644
--- a/Sprint-2/debug/author.js
+++ b/Sprint-2/debug/author.js
@@ -15,6 +15,6 @@ const author = {
   alive: true,
 };
 
-for (const value of author) {
+for (const value of Object.values(author)) {
   console.log(value);
 }

From fa4aee7c5a064cc75bfcf5fedb9ea088884b2be5 Mon Sep 17 00:00:00 2001
From: Precious Moses <mosesjeffrey74@gmail.com>
Date: Thu, 5 Nov 2026 19:59:59 +0000
Subject: [PATCH 05/52] Remove unnecessary comments and explanations from
 author.js

---
 Sprint-2/debug/author.js | 5 -----
 1 file changed, 5 deletions(-)

diff --git a/Sprint-2/debug/author.js b/Sprint-2/debug/author.js
index 63eec98c1..925ea5f54 100644
--- a/Sprint-2/debug/author.js
+++ b/Sprint-2/debug/author.js
@@ -1,8 +1,3 @@
-// Predict and explain first...
-
-// 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
-
 // explanation:
 // The code could not be executed because the for...of loop could not access object "author".
 // for...loops are used in arrays, strings or with certain array methods.

From ee40cba11f4615174035b20304e0991674ab4268 Mon Sep 17 00:00:00 2001
From: Precious Moses <mosesjeffrey74@gmail.com>
Date: Thu, 5 Nov 2026 20:06:24 +0000
Subject: [PATCH 06/52] refactor console log to correctly display ingredients
 list in recipe.js

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

diff --git a/Sprint-2/debug/recipe.js b/Sprint-2/debug/recipe.js
index 6cbdd22cd..a413b3332 100644
--- a/Sprint-2/debug/recipe.js
+++ b/Sprint-2/debug/recipe.js
@@ -12,4 +12,4 @@ const recipe = {
 
 console.log(`${recipe.title} serves ${recipe.serves}
   ingredients:
-${recipe}`);
+${recipe.ingredients.join("\n")}`);

From f4617bf3bf9934320f481d0b1bea42405cdd0e22 Mon Sep 17 00:00:00 2001
From: Precious Moses <mosesjeffrey74@gmail.com>
Date: Thu, 5 Nov 2026 20:08:00 +0000
Subject: [PATCH 07/52] Remove unnecessary comments from recipe.js

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

diff --git a/Sprint-2/debug/recipe.js b/Sprint-2/debug/recipe.js
index a413b3332..e6230ac41 100644
--- a/Sprint-2/debug/recipe.js
+++ b/Sprint-2/debug/recipe.js
@@ -1,9 +1,3 @@
-// Predict and explain first...
-
-// 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?
-
 const recipe = {
   title: "bruschetta",
   serves: 2,

From 106c55f1c4ce090eb875934c13f1c89d137173d1 Mon Sep 17 00:00:00 2001
From: Precious Moses <mosesjeffrey74@gmail.com>
Date: Thu, 5 Nov 2026 20:24:45 +0000
Subject: [PATCH 08/52] Implement test for contains function on empty object

---
 Sprint-2/implement/contains.test.js | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/Sprint-2/implement/contains.test.js b/Sprint-2/implement/contains.test.js
index 719272787..ecfa3f5c5 100644
--- a/Sprint-2/implement/contains.test.js
+++ b/Sprint-2/implement/contains.test.js
@@ -23,7 +23,9 @@ as an array isn't an object
 // Given an empty object
 // When passed to contains
 // Then it should return false
-test.todo("contains on empty object returns false");
+test("contains on empty object returns false", () => {
+  expect(contains({}, "name")).toBe(false);
+});
 
 // Given an object with properties
 // When passed to contains with an existing property name

From 9f620988b544bbaeff669dce09ecb0da4a429c8a Mon Sep 17 00:00:00 2001
From: Precious Moses <mosesjeffrey74@gmail.com>
Date: Thu, 5 Nov 2026 20:25:30 +0000
Subject: [PATCH 09/52] Implement contains function to return false

---
 Sprint-2/implement/contains.js | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/Sprint-2/implement/contains.js b/Sprint-2/implement/contains.js
index cd779308a..1a566c258 100644
--- a/Sprint-2/implement/contains.js
+++ b/Sprint-2/implement/contains.js
@@ -1,3 +1,5 @@
-function contains() {}
+function contains() {
+  return false;
+}
 
 module.exports = contains;

From 51be35cc252ee9c8437c724a7617ecddcadb7956 Mon Sep 17 00:00:00 2001
From: Precious Moses <mosesjeffrey74@gmail.com>
Date: Thu, 5 Nov 2026 20:50:20 +0000
Subject: [PATCH 10/52] Add test for contains function with existing property

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

diff --git a/Sprint-2/implement/contains.test.js b/Sprint-2/implement/contains.test.js
index ecfa3f5c5..276386018 100644
--- a/Sprint-2/implement/contains.test.js
+++ b/Sprint-2/implement/contains.test.js
@@ -30,6 +30,9 @@ test("contains on empty object returns false", () => {
 // Given an object with properties
 // When passed to contains with an existing property name
 // Then it should return true
+test("contains on object with existing property returns true", () => {
+  expect(contains({ name: "Moses", age: 30 }, "name")).toBe(true);
+});
 
 // Given an object with properties
 // When passed to contains with a non-existent property name

From f2a26fce347d1c9a0631bf0b88ddcb44bf6b5833 Mon Sep 17 00:00:00 2001
From: Precious Moses <mosesjeffrey74@gmail.com>
Date: Thu, 5 Nov 2026 20:53:39 +0000
Subject: [PATCH 11/52] Implement contains function to check for property
 existence in object

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

diff --git a/Sprint-2/implement/contains.js b/Sprint-2/implement/contains.js
index 1a566c258..de6e9c3e0 100644
--- a/Sprint-2/implement/contains.js
+++ b/Sprint-2/implement/contains.js
@@ -1,5 +1,5 @@
-function contains() {
-  return false;
+function contains(object, property) {
+  return Object.hasOwn(object, property);
 }
 
 module.exports = contains;

From 96cdc69ac158f1181bcc266b747d27dc5531def5 Mon Sep 17 00:00:00 2001
From: Precious Moses <mosesjeffrey74@gmail.com>
Date: Thu, 5 Nov 2026 21:03:07 +0000
Subject: [PATCH 12/52] Add tests for contains function with non-existent
 property and error handling

---
 Sprint-2/implement/contains.test.js | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/Sprint-2/implement/contains.test.js b/Sprint-2/implement/contains.test.js
index 276386018..00b283f0d 100644
--- a/Sprint-2/implement/contains.test.js
+++ b/Sprint-2/implement/contains.test.js
@@ -37,9 +37,17 @@ test("contains on object with existing property returns true", () => {
 // Given an object with properties
 // When passed to contains with a non-existent property name
 // Then it should return false
+test("contains on object with non-existent property returns false", () => {
+  expect(contains({ name: "Moses", age: 30 }, "city")).toBe(false);
+});
 
 // Given a value that isn't an object - an array, a string, a number,
 // null, or no argument at all
 // When passed to contains
 // Then it should throw Error("contains requires an object")
 // (careful: typeof [] and typeof null are both "object")
+test("contains throws an error for an array", () => {
+  expect(() => contains([1, 2, 3], "name")).toThrow(
+    "contains requires an object"
+  );
+});

From 990790e93fff5596639044780209d67f3e81cf9c Mon Sep 17 00:00:00 2001
From: Precious Moses <mosesjeffrey74@gmail.com>
Date: Thu, 5 Nov 2026 21:04:34 +0000
Subject: [PATCH 13/52] Add test for contains function to throw error for
 string input

---
 Sprint-2/implement/contains.test.js | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/Sprint-2/implement/contains.test.js b/Sprint-2/implement/contains.test.js
index 00b283f0d..5ca725663 100644
--- a/Sprint-2/implement/contains.test.js
+++ b/Sprint-2/implement/contains.test.js
@@ -51,3 +51,9 @@ test("contains throws an error for an array", () => {
     "contains requires an object"
   );
 });
+
+test("contains throws an error for a string", () => {
+  expect(() => contains("Manchester", "name")).toThrow(
+    "contains requires an object"
+  );
+});

From 8ea5fab7cb883a97146b19a447f29275483aabe9 Mon Sep 17 00:00:00 2001
From: Precious Moses <mosesjeffrey74@gmail.com>
Date: Thu, 5 Nov 2026 21:05:50 +0000
Subject: [PATCH 14/52] Add test for contains function to throw error for
 number input

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

diff --git a/Sprint-2/implement/contains.test.js b/Sprint-2/implement/contains.test.js
index 5ca725663..297a625d8 100644
--- a/Sprint-2/implement/contains.test.js
+++ b/Sprint-2/implement/contains.test.js
@@ -57,3 +57,7 @@ test("contains throws an error for a string", () => {
     "contains requires an object"
   );
 });
+
+test("contains throws an error for a number", () => {
+  expect(() => contains(30, "name")).toThrow("contains requires an object");
+});

From e586a0bf07291e59570f940c2c13afe11e390339 Mon Sep 17 00:00:00 2001
From: Precious Moses <mosesjeffrey74@gmail.com>
Date: Thu, 5 Nov 2026 21:06:37 +0000
Subject: [PATCH 15/52] Add test for contains function to throw error for null
 input

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

diff --git a/Sprint-2/implement/contains.test.js b/Sprint-2/implement/contains.test.js
index 297a625d8..6f0579912 100644
--- a/Sprint-2/implement/contains.test.js
+++ b/Sprint-2/implement/contains.test.js
@@ -61,3 +61,7 @@ test("contains throws an error for a string", () => {
 test("contains throws an error for a number", () => {
   expect(() => contains(30, "name")).toThrow("contains requires an object");
 });
+
+test("contains throws an error for null", () => {
+  expect(() => contains(null, "name")).toThrow("contains requires an object");
+});

From 9b77ec849188f780303a556d6eeecaa671d84d8e Mon Sep 17 00:00:00 2001
From: Precious Moses <mosesjeffrey74@gmail.com>
Date: Thu, 5 Nov 2026 21:07:34 +0000
Subject: [PATCH 16/52] Add test for contains function to throw error when no
 argument is given

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

diff --git a/Sprint-2/implement/contains.test.js b/Sprint-2/implement/contains.test.js
index 6f0579912..202fb3ea9 100644
--- a/Sprint-2/implement/contains.test.js
+++ b/Sprint-2/implement/contains.test.js
@@ -65,3 +65,7 @@ test("contains throws an error for a number", () => {
 test("contains throws an error for null", () => {
   expect(() => contains(null, "name")).toThrow("contains requires an object");
 });
+
+test("contains throws an error when no argument is given", () => {
+  expect(() => contains()).toThrow("contains requires an object");
+});

From 3ede0847677a034dd6d5e9631ff7e9b1fc6e64e9 Mon Sep 17 00:00:00 2001
From: Precious Moses <mosesjeffrey74@gmail.com>
Date: Thu, 5 Nov 2026 21:09:07 +0000
Subject: [PATCH 17/52] Remove unnecessary comments from contains test file

---
 Sprint-2/implement/contains.test.js | 14 --------------
 1 file changed, 14 deletions(-)

diff --git a/Sprint-2/implement/contains.test.js b/Sprint-2/implement/contains.test.js
index 202fb3ea9..19c6c9e4c 100644
--- a/Sprint-2/implement/contains.test.js
+++ b/Sprint-2/implement/contains.test.js
@@ -1,19 +1,5 @@
 const contains = require("./contains.js");
 
-/*
-Implement a function called contains that checks an object contains a
-particular property
-
-E.g. contains({a: 1, b: 2}, 'a') // returns true
-as the object contains a key of 'a'
-
-E.g. contains({a: 1, b: 2}, 'c') // returns false
-as the object doesn't contains a key of 'c'
-
-E.g. contains([1, 2, 3], 'a') throws Error("contains requires an object")
-as an array isn't an object
-*/
-
 // Acceptance criteria:
 
 // Given a contains function

From 26939b17b88b4c627b1375eb06b2bbfdc67f8d70 Mon Sep 17 00:00:00 2001
From: Precious Moses <mosesjeffrey74@gmail.com>
Date: Thu, 5 Nov 2026 21:11:29 +0000
Subject: [PATCH 18/52] Add validation to contains function to ensure input is
 an object

---
 Sprint-2/implement/contains.js | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/Sprint-2/implement/contains.js b/Sprint-2/implement/contains.js
index de6e9c3e0..f96b86673 100644
--- a/Sprint-2/implement/contains.js
+++ b/Sprint-2/implement/contains.js
@@ -1,4 +1,7 @@
 function contains(object, property) {
+  if (typeof object !== "object" || object === null || Array.isArray(object)) {
+    throw new Error("contains requires an object");
+  }
   return Object.hasOwn(object, property);
 }
 

From c6044d52d264e6980753816d48e43adb6d8053f1 Mon Sep 17 00:00:00 2001
From: Precious Moses <mosesjeffrey74@gmail.com>
Date: Thu, 5 Nov 2026 21:27:40 +0000
Subject: [PATCH 19/52] Implement test for country-currency pairs

---
 Sprint-2/implement/lookup.test.js | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/Sprint-2/implement/lookup.test.js b/Sprint-2/implement/lookup.test.js
index 547e06c5a..3c052eaf6 100644
--- a/Sprint-2/implement/lookup.test.js
+++ b/Sprint-2/implement/lookup.test.js
@@ -1,6 +1,14 @@
 const createLookup = require("./lookup.js");
 
-test.todo("creates a country currency code lookup for multiple codes");
+test("creates a country currency code lookup for multiple codes", () => {
+  const pairs = [
+    ["US", "USD"],
+    ["CA", "CAD"],
+  ];
+  const result = createLookup(pairs);
+
+  expect(result).toEqual({ US: "USD", CA: "CAD" });
+});
 
 /*
 

From 8c357a8ad817c8dde13212f2c6dd4a1e71232e1a Mon Sep 17 00:00:00 2001
From: Precious Moses <mosesjeffrey74@gmail.com>
Date: Thu, 5 Nov 2026 21:28:19 +0000
Subject: [PATCH 20/52] Implement createLookup function to map country codes to
 currency codes

---
 Sprint-2/implement/lookup.js | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/Sprint-2/implement/lookup.js b/Sprint-2/implement/lookup.js
index a6746e07f..c24eeec29 100644
--- a/Sprint-2/implement/lookup.js
+++ b/Sprint-2/implement/lookup.js
@@ -1,5 +1,13 @@
-function createLookup() {
-  // implementation here
+function createLookup(pairs) {
+  const lookup = [];
+
+  for (const pair of pairs) {
+    const countryCode = pair[0];
+    const currencyCode = pair[1];
+
+    lookup[countryCode] = currencyCode;
+  }
+  return lookup;
 }
 
 module.exports = createLookup;

From df599c5906079606e11317a6f8b7fd9faafecb92 Mon Sep 17 00:00:00 2001
From: Precious Moses <mosesjeffrey74@gmail.com>
Date: Thu, 5 Nov 2026 21:32:04 +0000
Subject: [PATCH 21/52] Refactor createLookup function to use an object instead
 of an array for lookup

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

diff --git a/Sprint-2/implement/lookup.js b/Sprint-2/implement/lookup.js
index c24eeec29..8d214aa97 100644
--- a/Sprint-2/implement/lookup.js
+++ b/Sprint-2/implement/lookup.js
@@ -1,5 +1,5 @@
 function createLookup(pairs) {
-  const lookup = [];
+  const lookup = {};
 
   for (const pair of pairs) {
     const countryCode = pair[0];

From 6440839ed9737f69d8bfe2277b371d9edb34c371 Mon Sep 17 00:00:00 2001
From: Precious Moses <mosesjeffrey74@gmail.com>
Date: Thu, 5 Nov 2026 21:33:16 +0000
Subject: [PATCH 22/52] Remove unnecessary comments from lookup test file

---
 Sprint-2/implement/lookup.test.js | 32 -------------------------------
 1 file changed, 32 deletions(-)

diff --git a/Sprint-2/implement/lookup.test.js b/Sprint-2/implement/lookup.test.js
index 3c052eaf6..ada04588c 100644
--- a/Sprint-2/implement/lookup.test.js
+++ b/Sprint-2/implement/lookup.test.js
@@ -9,35 +9,3 @@ test("creates a country currency code lookup for multiple codes", () => {
 
   expect(result).toEqual({ US: "USD", CA: "CAD" });
 });
-
-/*
-
-Create a lookup object of key value pairs from an array of code pairs
-
-Acceptance Criteria:
-
-Given
- - An array of arrays representing country code and currency code pairs
-   e.g. [['US', 'USD'], ['CA', 'CAD']]
-
-When
- - createLookup function is called with the country-currency array as an argument
-
-Then
- - It should return an object where:
- - The keys are the country codes
- - The values are the corresponding currency codes
-
-Example
-Given: [['US', 'USD'], ['CA', 'CAD']]
-
-When
-createLookup(countryCurrencyPairs) is called
-
-Then
-It should return:
- {
-   'US': 'USD',
-   'CA': 'CAD'
- }
-*/

From dc9fbcd566115b27909bc78fdc3827aa586f20f0 Mon Sep 17 00:00:00 2001
From: Precious Moses <mosesjeffrey74@gmail.com>
Date: Thu, 5 Nov 2026 21:40:50 +0000
Subject: [PATCH 23/52] Implement test for tally function on an empty array

---
 Sprint-2/implement/tally.test.js | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/Sprint-2/implement/tally.test.js b/Sprint-2/implement/tally.test.js
index ca763c296..55a4c77ad 100644
--- a/Sprint-2/implement/tally.test.js
+++ b/Sprint-2/implement/tally.test.js
@@ -23,7 +23,9 @@ const tally = require("./tally.js");
 // 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");
+test("tally on an empty array returns an empty object", () => {
+  expect(tally([])).toEqual({});
+});
 
 // Given an array with duplicate items
 // When passed to tally

From cbe89f11dbbf206561f73e2d406621dabfad1847 Mon Sep 17 00:00:00 2001
From: Precious Moses <mosesjeffrey74@gmail.com>
Date: Thu, 5 Nov 2026 21:41:24 +0000
Subject: [PATCH 24/52] Implement return statement in tally function

---
 Sprint-2/implement/tally.js | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/Sprint-2/implement/tally.js b/Sprint-2/implement/tally.js
index f47321812..011b683a8 100644
--- a/Sprint-2/implement/tally.js
+++ b/Sprint-2/implement/tally.js
@@ -1,3 +1,5 @@
-function tally() {}
+function tally() {
+  return {};
+}
 
 module.exports = tally;

From 0df25388be10c0157732b08b9ffcf28238917739 Mon Sep 17 00:00:00 2001
From: Precious Moses <mosesjeffrey74@gmail.com>
Date: Thu, 5 Nov 2026 21:50:41 +0000
Subject: [PATCH 25/52] Add test for tally function to count duplicate items

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

diff --git a/Sprint-2/implement/tally.test.js b/Sprint-2/implement/tally.test.js
index 55a4c77ad..7fce65e22 100644
--- a/Sprint-2/implement/tally.test.js
+++ b/Sprint-2/implement/tally.test.js
@@ -30,6 +30,9 @@ test("tally on an empty array returns an empty object", () => {
 // Given an array with duplicate items
 // When passed to tally
 // Then it should return counts for each unique item
+test("tally counts duplicate items", () => {
+  expect(tally(["a", "a", "a"])).toEqual({ a: 3 });
+});
 
 // Given an invalid input like a string, a number, or no argument at all
 // When passed to tally

From c08d7ad2e7716c7b8b908b91beabf2a99ee13f0a Mon Sep 17 00:00:00 2001
From: Precious Moses <mosesjeffrey74@gmail.com>
Date: Thu, 5 Nov 2026 21:52:21 +0000
Subject: [PATCH 26/52] Add test for tally function to verify counts for unique
 items

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

diff --git a/Sprint-2/implement/tally.test.js b/Sprint-2/implement/tally.test.js
index 7fce65e22..35254ddb2 100644
--- a/Sprint-2/implement/tally.test.js
+++ b/Sprint-2/implement/tally.test.js
@@ -33,6 +33,9 @@ test("tally on an empty array returns an empty object", () => {
 test("tally counts duplicate items", () => {
   expect(tally(["a", "a", "a"])).toEqual({ a: 3 });
 });
+test("tally returns count for each unique item", () => {
+  expect(tally(["a", "a", "b", "c"])).toEqual({ a: 2, b: 1, c: 1 });
+});
 
 // Given an invalid input like a string, a number, or no argument at all
 // When passed to tally

From f82e06420e945a9883afb435497b938e6615908a Mon Sep 17 00:00:00 2001
From: Precious Moses <mosesjeffrey74@gmail.com>
Date: Thu, 5 Nov 2026 21:59:37 +0000
Subject: [PATCH 27/52] Implement tally function to count occurrences of items
 in an array

---
 Sprint-2/implement/tally.js | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/Sprint-2/implement/tally.js b/Sprint-2/implement/tally.js
index 011b683a8..f548aecef 100644
--- a/Sprint-2/implement/tally.js
+++ b/Sprint-2/implement/tally.js
@@ -1,5 +1,14 @@
-function tally() {
-  return {};
+function tally(items) {
+  const counts = {};
+
+  for (const item of items) {
+    if (counts[item] === undefined) {
+      counts[item] = 1;
+    } else {
+      counts[item] += 1;
+    }
+  }
+  return counts;
 }
 
 module.exports = tally;

From b6f88e865650149279a98b5b8211fd55bcdd7002 Mon Sep 17 00:00:00 2001
From: Precious Moses <mosesjeffrey74@gmail.com>
Date: Thu, 5 Nov 2026 22:15:24 +0000
Subject: [PATCH 28/52] Add test for tally function to handle invalid input

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

diff --git a/Sprint-2/implement/tally.test.js b/Sprint-2/implement/tally.test.js
index 35254ddb2..2dcbde96c 100644
--- a/Sprint-2/implement/tally.test.js
+++ b/Sprint-2/implement/tally.test.js
@@ -40,3 +40,8 @@ test("tally returns count for each unique item", () => {
 // Given an invalid input like a string, a number, or no argument at all
 // When passed to tally
 // Then it should throw Error("tally requires an array")
+test("tally throws an error when given an invalid input", () => {
+  expect(() => tally("hello")).toThrow(new Error("tally requires an array"));
+  expect(() => tally(30)).toThrow(new Error("tally requires an array"));
+  expect(() => tally()).toThrow(new Error("tally requires an array"));
+});

From b8fe136a4b9b9b27d2f315f3c37eaa79a8f93f5e Mon Sep 17 00:00:00 2001
From: Precious Moses <mosesjeffrey74@gmail.com>
Date: Thu, 5 Nov 2026 22:17:33 +0000
Subject: [PATCH 29/52] Add input validation to tally function to ensure an
 array is provided

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

diff --git a/Sprint-2/implement/tally.js b/Sprint-2/implement/tally.js
index f548aecef..7ab2d0dc6 100644
--- a/Sprint-2/implement/tally.js
+++ b/Sprint-2/implement/tally.js
@@ -1,4 +1,8 @@
 function tally(items) {
+  if (!Array.isArray(items)) {
+    throw new Error("tally requires an array");
+  }
+
   const counts = {};
 
   for (const item of items) {

From 625a080d8f660df50d68a4b12f21380b826b5149 Mon Sep 17 00:00:00 2001
From: Precious Moses <mosesjeffrey74@gmail.com>
Date: Thu, 5 Nov 2026 22:19:18 +0000
Subject: [PATCH 30/52] Remove unnecessary comments from tally test file for
 clarity

---
 Sprint-2/implement/tally.test.js | 14 --------------
 1 file changed, 14 deletions(-)

diff --git a/Sprint-2/implement/tally.test.js b/Sprint-2/implement/tally.test.js
index 2dcbde96c..ab50cbead 100644
--- a/Sprint-2/implement/tally.test.js
+++ b/Sprint-2/implement/tally.test.js
@@ -1,19 +1,5 @@
 const tally = require("./tally.js");
 
-/**
- * tally array
- *
- * In this task, you'll need to implement a function called tally
- * that will take a list of items and count the frequency of each item
- * in an array
- *
- * For example:
- *
- * tally(['a']), target output: { a: 1 }
- * tally(['a', 'a', 'a']), target output: { a: 3 }
- * tally(['a', 'a', 'b', 'c']), target output: { a : 2, b: 1, c: 1 }
- */
-
 // Acceptance criteria:
 
 // Given a function called tally

From 86acb174f5a39d3fde17ad61c3f77722d67827b9 Mon Sep 17 00:00:00 2001
From: Precious Moses <mosesjeffrey74@gmail.com>
Date: Thu, 5 Nov 2026 22:37:21 +0000
Subject: [PATCH 31/52] Refactor parseQueryString to use indexOf and slice for
 key-value extraction

---
 Sprint-2/implement/querystring.js | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/Sprint-2/implement/querystring.js b/Sprint-2/implement/querystring.js
index 45ec4e5f3..84b6a41fa 100644
--- a/Sprint-2/implement/querystring.js
+++ b/Sprint-2/implement/querystring.js
@@ -6,7 +6,9 @@ function parseQueryString(queryString) {
   const keyValuePairs = queryString.split("&");
 
   for (const pair of keyValuePairs) {
-    const [key, value] = pair.split("=");
+    const index = pair.indexOf("=");
+    const key = pair.slice(0, index);
+    const value = pair.slice(index + 1);
     queryParams[key] = value;
   }
 

From dff6f8c975653d7df3d603a2876d9f07a35d08e7 Mon Sep 17 00:00:00 2001
From: Precious Moses <mosesjeffrey74@gmail.com>
Date: Thu, 5 Nov 2026 22:38:56 +0000
Subject: [PATCH 32/52] Fix parseQueryString to skip empty key-value pairs in
 query string

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

diff --git a/Sprint-2/implement/querystring.js b/Sprint-2/implement/querystring.js
index 84b6a41fa..b69ced1fd 100644
--- a/Sprint-2/implement/querystring.js
+++ b/Sprint-2/implement/querystring.js
@@ -6,6 +6,8 @@ function parseQueryString(queryString) {
   const keyValuePairs = queryString.split("&");
 
   for (const pair of keyValuePairs) {
+    if (pair === "") continue;
+
     const index = pair.indexOf("=");
     const key = pair.slice(0, index);
     const value = pair.slice(index + 1);

From 50c10376b99a82df84ed0e7fec3adfed318d1daf Mon Sep 17 00:00:00 2001
From: Precious Moses <mosesjeffrey74@gmail.com>
Date: Thu, 5 Nov 2026 22:44:48 +0000
Subject: [PATCH 33/52] Refactor parseQueryString to handle key-value
 extraction with conditional checks

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

diff --git a/Sprint-2/implement/querystring.js b/Sprint-2/implement/querystring.js
index b69ced1fd..96c05a61b 100644
--- a/Sprint-2/implement/querystring.js
+++ b/Sprint-2/implement/querystring.js
@@ -9,8 +9,9 @@ function parseQueryString(queryString) {
     if (pair === "") continue;
 
     const index = pair.indexOf("=");
-    const key = pair.slice(0, index);
-    const value = pair.slice(index + 1);
+    const separator = index !== -1;
+    const key = separator ? pair.slice(0, index) : pair;
+    const value = separator ? pair.slice(index + 1) : "";
     queryParams[key] = value;
   }
 

From 53bcc81b136533c4fd4201ce971bffd420020927 Mon Sep 17 00:00:00 2001
From: Precious Moses <mosesjeffrey74@gmail.com>
Date: Thu, 5 Nov 2026 22:54:16 +0000
Subject: [PATCH 34/52] Enhance parseQueryString to decode keys and values for
 improved query parameter handling

---
 Sprint-2/implement/querystring.js | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/Sprint-2/implement/querystring.js b/Sprint-2/implement/querystring.js
index 96c05a61b..3c589930f 100644
--- a/Sprint-2/implement/querystring.js
+++ b/Sprint-2/implement/querystring.js
@@ -1,3 +1,7 @@
+function decode(text) {
+  return decodeURIComponent(text.replace(/\+/g, " "));
+}
+
 function parseQueryString(queryString) {
   const queryParams = {};
   if (queryString.length === 0) {
@@ -10,8 +14,11 @@ function parseQueryString(queryString) {
 
     const index = pair.indexOf("=");
     const separator = index !== -1;
-    const key = separator ? pair.slice(0, index) : pair;
-    const value = separator ? pair.slice(index + 1) : "";
+    const rawKey = separator ? pair.slice(0, index) : pair;
+    const rawValue = separator ? pair.slice(index + 1) : "";
+
+    const key = decode(rawKey);
+    const value = decode(rawValue);
     queryParams[key] = value;
   }
 

From 40770d83b889d20f29596ca7195ff0aaf0e2039c Mon Sep 17 00:00:00 2001
From: Precious Moses <mosesjeffrey74@gmail.com>
Date: Thu, 5 Nov 2026 23:04:22 +0000
Subject: [PATCH 35/52] Refactor parseQueryString to support multiple values
 for the same key

---
 Sprint-2/implement/querystring.js | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/Sprint-2/implement/querystring.js b/Sprint-2/implement/querystring.js
index 3c589930f..afc9ae1f1 100644
--- a/Sprint-2/implement/querystring.js
+++ b/Sprint-2/implement/querystring.js
@@ -19,7 +19,16 @@ function parseQueryString(queryString) {
 
     const key = decode(rawKey);
     const value = decode(rawValue);
-    queryParams[key] = value;
+
+    if (key in queryParams) {
+      if (Array.isArray(queryParams[key])) {
+        queryParams[key].push(value);
+      } else {
+        queryParams[key] = [queryParams[key], value];
+      }
+    } else {
+      queryParams[key] = value;
+    }
   }
 
   return queryParams;

From 89aa7c840b9c7f12a5545b53d00106421b0cd220 Mon Sep 17 00:00:00 2001
From: Precious Moses <mosesjeffrey74@gmail.com>
Date: Thu, 5 Nov 2026 23:11:04 +0000
Subject: [PATCH 36/52] add edge case test for malformed percent-encoding

---
 Sprint-2/implement/querystring.test.js | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/Sprint-2/implement/querystring.test.js b/Sprint-2/implement/querystring.test.js
index 328b8df61..adbfc2965 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({
@@ -46,3 +46,8 @@ test("should store values of a key in an array when the key has 2 or more values
     foo: "bar",
   });
 });
+
+// Edge cases
+test("should not crash on malformed percent-encoding", () => {
+  expect(parseQueryString("a=%E0%A4%A")).toEqual({ a: "%E0%A4%A" });
+});

From 55bcc8ed09f98e1120f45bf901b55caf26e26f8b Mon Sep 17 00:00:00 2001
From: Precious Moses <mosesjeffrey74@gmail.com>
Date: Thu, 5 Nov 2026 23:13:07 +0000
Subject: [PATCH 37/52] Refactor decode function to handle errors and replace
 plus signs with spaces

---
 Sprint-2/implement/querystring.js | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/Sprint-2/implement/querystring.js b/Sprint-2/implement/querystring.js
index afc9ae1f1..e457f3e56 100644
--- a/Sprint-2/implement/querystring.js
+++ b/Sprint-2/implement/querystring.js
@@ -1,5 +1,10 @@
 function decode(text) {
-  return decodeURIComponent(text.replace(/\+/g, " "));
+  const withSpaces = text.replace(/\+/g, " ");
+  try {
+    return decodeURIComponent(withSpaces);
+  } catch {
+    return withSpaces;
+  }
 }
 
 function parseQueryString(queryString) {

From 01bf866bebe543528fff9dac4a3a7f422d9cc691 Mon Sep 17 00:00:00 2001
From: Precious Moses <mosesjeffrey74@gmail.com>
Date: Fri, 6 Nov 2026 01:00:14 +0000
Subject: [PATCH 38/52] Update comment to clarify current return value for
 invert function

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

diff --git a/Sprint-2/interpret/invert.js b/Sprint-2/interpret/invert.js
index bb353fb1f..5e6c342b9 100644
--- a/Sprint-2/interpret/invert.js
+++ b/Sprint-2/interpret/invert.js
@@ -17,6 +17,7 @@ function invert(obj) {
 }
 
 // a) What is the current return value when invert is called with { a : 1 }
+// Current return value is 1.
 
 // b) What is the current return value when invert is called with { a: 1, b: 2 }
 

From 3e4344a75d98e2eced5b2a74f1c67de47728517b Mon Sep 17 00:00:00 2001
From: Precious Moses <mosesjeffrey74@gmail.com>
Date: Fri, 6 Nov 2026 01:00:39 +0000
Subject: [PATCH 39/52] Update comment to clarify current return value for
 invert function with multiple key-value pairs

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

diff --git a/Sprint-2/interpret/invert.js b/Sprint-2/interpret/invert.js
index 5e6c342b9..8d2bbd66b 100644
--- a/Sprint-2/interpret/invert.js
+++ b/Sprint-2/interpret/invert.js
@@ -20,6 +20,7 @@ function invert(obj) {
 // Current return value is 1.
 
 // b) What is the current return value when invert is called with { a: 1, b: 2 }
+// The current return value is 2.
 
 // c) What is the target return value when invert is called with {a : 1, b: 2}
 

From b3d7030499e8d93de9cf45e192f67be005da9a53 Mon Sep 17 00:00:00 2001
From: Precious Moses <mosesjeffrey74@gmail.com>
Date: Fri, 6 Nov 2026 01:01:16 +0000
Subject: [PATCH 40/52] Update comment to clarify target return value for
 invert function with multiple key-value pairs

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

diff --git a/Sprint-2/interpret/invert.js b/Sprint-2/interpret/invert.js
index 8d2bbd66b..7a88199b6 100644
--- a/Sprint-2/interpret/invert.js
+++ b/Sprint-2/interpret/invert.js
@@ -23,6 +23,7 @@ function invert(obj) {
 // The current return value is 2.
 
 // c) What is the target return value when invert is called with {a : 1, b: 2}
+// The target value is { "1": "a", "2": "b"}
 
 // c) What does Object.entries return? Why is it needed in this program?
 

From 4ebef47bb8a265212482058812b8040e34310ded Mon Sep 17 00:00:00 2001
From: Precious Moses <mosesjeffrey74@gmail.com>
Date: Fri, 6 Nov 2026 01:02:46 +0000
Subject: [PATCH 41/52] Update comments to clarify the purpose of
 Object.entries in the invert function

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

diff --git a/Sprint-2/interpret/invert.js b/Sprint-2/interpret/invert.js
index 7a88199b6..ace76e913 100644
--- a/Sprint-2/interpret/invert.js
+++ b/Sprint-2/interpret/invert.js
@@ -26,6 +26,8 @@ function invert(obj) {
 // The target value is { "1": "a", "2": "b"}
 
 // c) What does Object.entries return? Why is it needed in this program?
+// Object.entries returns an array of object [key, value] pairs.
+// It converts an object into an array, so the loop works, since plain objects can't be used with loops.
 
 // d) Explain why the current return value is different from the target output
 

From cffb378b3101c1ece74766e9877ee5fb0120a44c Mon Sep 17 00:00:00 2001
From: Precious Moses <mosesjeffrey74@gmail.com>
Date: Fri, 6 Nov 2026 01:03:48 +0000
Subject: [PATCH 42/52] Update comments to clarify the reason for the current
 return value in the invert function

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

diff --git a/Sprint-2/interpret/invert.js b/Sprint-2/interpret/invert.js
index ace76e913..5529e66fd 100644
--- a/Sprint-2/interpret/invert.js
+++ b/Sprint-2/interpret/invert.js
@@ -30,5 +30,7 @@ function invert(obj) {
 // It converts an object into an array, so the loop works, since plain objects can't be used with loops.
 
 // d) Explain why the current return value is different from the target output
+// It differs due to the fact that "invertedObj.key" uses the wrong notation, "key", instead of the variable's value.
+// Also, adding brackets to the literal name, [key], would only copy the object not fix it.
 
 // e) Fix the implementation of invert (and write tests to prove it's fixed!)

From f6adbf39621a0dc1425407924280909d02d7f092 Mon Sep 17 00:00:00 2001
From: Precious Moses <mosesjeffrey74@gmail.com>
Date: Fri, 6 Nov 2026 01:06:38 +0000
Subject: [PATCH 43/52] Fix invert function to correctly swap keys and values;
 add initial test file

---
 Sprint-2/interpret/invert.js      | 2 +-
 Sprint-2/interpret/invert.test.js | 0
 2 files changed, 1 insertion(+), 1 deletion(-)
 create mode 100644 Sprint-2/interpret/invert.test.js

diff --git a/Sprint-2/interpret/invert.js b/Sprint-2/interpret/invert.js
index 5529e66fd..f4893135e 100644
--- a/Sprint-2/interpret/invert.js
+++ b/Sprint-2/interpret/invert.js
@@ -10,7 +10,7 @@ function invert(obj) {
   const invertedObj = {};
 
   for (const [key, value] of Object.entries(obj)) {
-    invertedObj.key = value;
+    invertedObj[value] = key;
   }
 
   return invertedObj;
diff --git a/Sprint-2/interpret/invert.test.js b/Sprint-2/interpret/invert.test.js
new file mode 100644
index 000000000..e69de29bb

From c5db3decef0e5e7649f61da153cb2628714ac2d8 Mon Sep 17 00:00:00 2001
From: Precious Moses <mosesjeffrey74@gmail.com>
Date: Fri, 6 Nov 2026 01:13:13 +0000
Subject: [PATCH 44/52] Add invert function and initial test case for key-value
 swapping

---
 Sprint-2/interpret/invert.js      | 2 ++
 Sprint-2/interpret/invert.test.js | 5 +++++
 2 files changed, 7 insertions(+)

diff --git a/Sprint-2/interpret/invert.js b/Sprint-2/interpret/invert.js
index f4893135e..fbe899b3c 100644
--- a/Sprint-2/interpret/invert.js
+++ b/Sprint-2/interpret/invert.js
@@ -16,6 +16,8 @@ function invert(obj) {
   return invertedObj;
 }
 
+module.exports = invert;
+
 // a) What is the current return value when invert is called with { a : 1 }
 // Current return value is 1.
 
diff --git a/Sprint-2/interpret/invert.test.js b/Sprint-2/interpret/invert.test.js
index e69de29bb..6876445d2 100644
--- a/Sprint-2/interpret/invert.test.js
+++ b/Sprint-2/interpret/invert.test.js
@@ -0,0 +1,5 @@
+const invert = require("./invert");
+
+test("swaps the key and value of a single pair", () => {
+  expect(invert({ a: 1 })).toEqual({ 1: "a" });
+});

From f0daded0c24aab8abe861849c5f72fa1b932bfe3 Mon Sep 17 00:00:00 2001
From: Precious Moses <mosesjeffrey74@gmail.com>
Date: Fri, 6 Nov 2026 01:16:46 +0000
Subject: [PATCH 45/52] Add test case for multiple key-value pairs in invert
 function

---
 Sprint-2/interpret/invert.test.js | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/Sprint-2/interpret/invert.test.js b/Sprint-2/interpret/invert.test.js
index 6876445d2..4545dca3a 100644
--- a/Sprint-2/interpret/invert.test.js
+++ b/Sprint-2/interpret/invert.test.js
@@ -3,3 +3,7 @@ const invert = require("./invert");
 test("swaps the key and value of a single pair", () => {
   expect(invert({ a: 1 })).toEqual({ 1: "a" });
 });
+
+test("swaps every pair when there are multiple pairs", () => {
+  expect(invert({ a: 1, b: 2 })).toEqual({ 1: "a", 2: "b" });
+});

From a45c5ea065c8801a123c7205b02a359e931091c7 Mon Sep 17 00:00:00 2001
From: Precious Moses <mosesjeffrey74@gmail.com>
Date: Fri, 6 Nov 2026 01:18:13 +0000
Subject: [PATCH 46/52] Update test case for multiple key-value pairs in invert
 function

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

diff --git a/Sprint-2/interpret/invert.test.js b/Sprint-2/interpret/invert.test.js
index 4545dca3a..f63004f6a 100644
--- a/Sprint-2/interpret/invert.test.js
+++ b/Sprint-2/interpret/invert.test.js
@@ -5,5 +5,5 @@ test("swaps the key and value of a single pair", () => {
 });
 
 test("swaps every pair when there are multiple pairs", () => {
-  expect(invert({ a: 1, b: 2 })).toEqual({ 1: "a", 2: "b" });
+  expect(invert({ x: 10, y: 20 })).toEqual({ 10: "a", 20: "b" });
 });

From 41a07a18c6f15e3bd05dfd18cbd2ece34a485319 Mon Sep 17 00:00:00 2001
From: Precious Moses <mosesjeffrey74@gmail.com>
Date: Fri, 6 Nov 2026 01:27:19 +0000
Subject: [PATCH 47/52] Add test case for returning an empty object in invert
 function

---
 Sprint-2/interpret/invert.test.js | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/Sprint-2/interpret/invert.test.js b/Sprint-2/interpret/invert.test.js
index f63004f6a..1b3933ba8 100644
--- a/Sprint-2/interpret/invert.test.js
+++ b/Sprint-2/interpret/invert.test.js
@@ -5,5 +5,9 @@ test("swaps the key and value of a single pair", () => {
 });
 
 test("swaps every pair when there are multiple pairs", () => {
-  expect(invert({ x: 10, y: 20 })).toEqual({ 10: "a", 20: "b" });
+  expect(invert({ x: 10, y: 20 })).toEqual({ 10: "x", 20: "y" });
+});
+
+test("returns an empty object when given an empty object", () => {
+  expect(invert({})).toEqual({});
 });

From 1d46b2242762b528777ca5412ed0c961d14ed904 Mon Sep 17 00:00:00 2001
From: Precious Moses <mosesjeffrey74@gmail.com>
Date: Fri, 6 Nov 2026 01:29:24 +0000
Subject: [PATCH 48/52] Remove unnecessary comments

---
 Sprint-2/interpret/invert.js | 8 --------
 1 file changed, 8 deletions(-)

diff --git a/Sprint-2/interpret/invert.js b/Sprint-2/interpret/invert.js
index fbe899b3c..70eae6771 100644
--- a/Sprint-2/interpret/invert.js
+++ b/Sprint-2/interpret/invert.js
@@ -1,11 +1,3 @@
-// Let's define how invert should work
-
-// Given an object
-// When invert is passed this object
-// Then it should swap the keys and values in the object
-
-// E.g. invert({x : 10, y : 20}), target output: {"10": "x", "20": "y"}
-
 function invert(obj) {
   const invertedObj = {};
 

From 69b6210173f548e2dd6a3f27760422c2c06f7f08 Mon Sep 17 00:00:00 2001
From: Precious Moses <mosesjeffrey74@gmail.com>
Date: Sun, 8 Nov 2026 21:04:42 +0000
Subject: [PATCH 49/52] Update error message tests in contains function for
 consistency

---
 Sprint-2/implement/contains.test.js | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/Sprint-2/implement/contains.test.js b/Sprint-2/implement/contains.test.js
index 19c6c9e4c..2be0788d7 100644
--- a/Sprint-2/implement/contains.test.js
+++ b/Sprint-2/implement/contains.test.js
@@ -33,13 +33,11 @@ test("contains on object with non-existent property returns false", () => {
 // Then it should throw Error("contains requires an object")
 // (careful: typeof [] and typeof null are both "object")
 test("contains throws an error for an array", () => {
-  expect(() => contains([1, 2, 3], "name")).toThrow(
-    "contains requires an object"
-  );
+  expect(() => contains([1, 2, 3], "0")).toThrow("contains requires an object");
 });
 
 test("contains throws an error for a string", () => {
-  expect(() => contains("Manchester", "name")).toThrow(
+  expect(() => contains("Manchester", "0")).toThrow(
     "contains requires an object"
   );
 });

From 78a1f82b6829c3e7269b7f5e11dcdae26514117f Mon Sep 17 00:00:00 2001
From: Precious Moses <mosesjeffrey74@gmail.com>
Date: Sun, 8 Nov 2026 21:15:50 +0000
Subject: [PATCH 50/52] Add test case for handling items named like built-in
 object properties in tally function

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

diff --git a/Sprint-2/implement/tally.test.js b/Sprint-2/implement/tally.test.js
index ab50cbead..3ef40e625 100644
--- a/Sprint-2/implement/tally.test.js
+++ b/Sprint-2/implement/tally.test.js
@@ -31,3 +31,8 @@ test("tally throws an error when given an invalid input", () => {
   expect(() => tally(30)).toThrow(new Error("tally requires an array"));
   expect(() => tally()).toThrow(new Error("tally requires an array"));
 });
+
+// Tally handles items named like built-in object properties
+test("tally handles items named like built-in object properties", () => {
+  expect(tally(["toString", "toString"])).toEqual({ toString: 2 });
+});

From 12a783ed70d85b68c28b6487977c98ab5994aa09 Mon Sep 17 00:00:00 2001
From: Precious Moses <mosesjeffrey74@gmail.com>
Date: Sun, 8 Nov 2026 21:18:50 +0000
Subject: [PATCH 51/52] Refactor tally function to simplify item counting logic

---
 Sprint-2/implement/tally.js | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/Sprint-2/implement/tally.js b/Sprint-2/implement/tally.js
index 7ab2d0dc6..e5dbcbcbf 100644
--- a/Sprint-2/implement/tally.js
+++ b/Sprint-2/implement/tally.js
@@ -6,10 +6,10 @@ function tally(items) {
   const counts = {};
 
   for (const item of items) {
-    if (counts[item] === undefined) {
-      counts[item] = 1;
-    } else {
+    if (Object.hasOwn(counts, item)) {
       counts[item] += 1;
+    } else {
+      counts[item] = 1;
     }
   }
   return counts;

From 63734356764d2880ce705bf143470319eb879385 Mon Sep 17 00:00:00 2001
From: Precious Moses <mosesjeffrey74@gmail.com>
Date: Sun, 8 Nov 2026 21:25:08 +0000
Subject: [PATCH 52/52] Update comments in invert function to clarify return
 values

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

diff --git a/Sprint-2/interpret/invert.js b/Sprint-2/interpret/invert.js
index 70eae6771..039621169 100644
--- a/Sprint-2/interpret/invert.js
+++ b/Sprint-2/interpret/invert.js
@@ -11,10 +11,10 @@ function invert(obj) {
 module.exports = invert;
 
 // a) What is the current return value when invert is called with { a : 1 }
-// Current return value is 1.
+// Current return value is an object, { key: 1 }
 
 // b) What is the current return value when invert is called with { a: 1, b: 2 }
-// The current return value is 2.
+// The current return value is an object also, { key: 2 }
 
 // c) What is the target return value when invert is called with {a : 1, b: 2}
 // The target value is { "1": "a", "2": "b"}