London | 25-ITP-SEP | Imran Mohamed | Sprint 2 | Sprint-2 exercises

Sprint-2/debug/address.js

@@ -1,5 +1,7 @@
 // Predict and explain first...
 
+//The code will not log the house number as it is using the wrong syntax to access the property.
+
 // This code should log out the houseNumber from the address object
 // but it isn't working...
 // Fix anything that isn't working
@@ -12,4 +14,4 @@ const address = {
   postcode: "XYZ 123",
 };
 
-console.log(`My house number is ${address[0]}`);
+console.log(`My house number is ${address.houseNumber}`);

Sprint-2/debug/author.js

@@ -1,5 +1,7 @@
 // Predict and explain first...
 
+// The code will not log the values of the object because a for of loop cannot be used on 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 +13,6 @@ const author = {
   alive: true,
 };
 
-for (const value of author) {
-  console.log(value);
+for (const value in author) {
+  console.log(author[value]);
 }

Sprint-2/debug/recipe.js

@@ -1,5 +1,7 @@
 // Predict and explain first...
 
+//The code is log the title and serves correctly, but will not log the ingredients properly because it is trying to log the entire recipe object and not the ingredients array
+
 // 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?
@@ -12,4 +14,4 @@ const recipe = {
 
 console.log(`${recipe.title} serves ${recipe.serves}
   ingredients:
-${recipe}`);
+${recipe.ingredients.join('\n')}`);

Sprint-2/implement/contains.js

@@ -1,3 +1,12 @@
-function contains() {}
+function contains(obj, prop) {
+    if(arguments.length !== 2){
+        throw new Error('Invalid input: function requires two arguments');
+    }
+    if (obj === null || typeof obj !== 'object' || Array.isArray(obj)) {
+        throw new Error('Invalid input: first argument must be an object');
+    }
+    return obj.hasOwnProperty(prop);
+
+}
 
 module.exports = contains;

Sprint-2/implement/contains.test.js

@@ -20,16 +20,65 @@ as the object doesn't contains a key of 'c'
 // Given an empty object
 // When passed to contains
 // Then it should return false
-test.todo("contains on empty object returns false");
+test("should return false when passed an empty object", () => {
+  expect(contains({}, "a")).toBe(false);
+}); 
 
 // Given an object with properties
 // When passed to contains with an existing property name
 // Then it should return true
+test("should return true when the object contains the property", () => {
+  expect(contains({ a: 1, b: 2 }, "a")).toBe(true);
+});
 
 // Given an object with properties
 // When passed to contains with a non-existent property name
-// Then it should return false
+// Then it should return false 
+test("should return false when the object does not contain the property", () => {
+  expect(contains({ a: 1, b: 2 }, "c")).toBe(false);
+});
 
 // Given invalid parameters like an array
 // When passed to contains
 // Then it should return false or throw an error
+
+describe('error on invalid input', () => { 
+    test.each([
+      [null, 'a'],
+      [undefined, 'a'],
+      [42, 'a'],
+      ['string', 'a'],
+      [true, 'a'],
+      [[], 'a'],
+    ])('contains(%p, %p) should throw an error', (obj, prop) => {
+      expect(() => contains(obj, prop)).toThrow('Invalid input: first argument must be an object');
+    });
+  });   
+
+// Given an object with a property set to undefined
+test("should return true when the property exists but is undefined", () => {
+  expect(contains({ a: undefined, b: 2 }, "a")).toBe(true);
+});
+
+// Given an object with a property set to null
+test("should return true when the property exists but is null", () => {
+  expect(contains({ a: null, b: 2 }, "a")).toBe(true);
+});
+
+// Given an object with a property whose value is falsy
+test("should return true when the property exists but is falsy", () => {
+  expect(contains({ a: 0, b: false, c: '', d: NaN }, "a")).toBe(true);
+  expect(contains({ a: 0, b: false, c: '', d: NaN }, "b")).toBe(true);
+  expect(contains({ a: 0, b: false, c: '', d: NaN }, "c")).toBe(true);
+  expect(contains({ a: 0, b: false, c: '', d: NaN }, "d")).toBe(true);
+});
+
+//incorrect arguments
+test("should throw an error when called with incorrect number of arguments", () => {
+  expect(() => contains({ a: 1 })).toThrow('Invalid input: function requires two arguments');
+  expect(() => contains()).toThrow('Invalid input: function requires two arguments');
+  expect(() => contains({ a: 1 }, 'a', 'extra')).toThrow('Invalid input: function requires two arguments');
+});
+
+
+

Sprint-2/implement/lookup.js

@@ -1,5 +1,29 @@
-function createLookup() {
-  // implementation here
+function createLookup(arr) {
+  if(!arguments.length) {
+    throw new Error('No arguments provided');
+  }
+  const result = {};
+  if (!Array.isArray(arr)) {
+    return result;
+  }
+  for (const item of arr) {
+    if (Array.isArray(item) && item.length >= 2) {
+
+      const [country, currency] = item;
+
+      if (currency === null || currency === undefined) {
+        continue;
+      }
+
+
+      if (((Array.isArray(currency) && currency.length)|| (typeof currency === 'string' && currency.length)) 
+        && typeof country === "string" && country.length) {
+        result[country] = result[country] ? [result[country], currency] : currency; 
+      }
+
+    }
+  } 
+  return result;
 }
 
-module.exports = createLookup;
+module.exports = createLookup

Sprint-2/implement/lookup.test.js

@@ -1,7 +1,4 @@
-const createLookup = require("./lookup.js");
-
-test.todo("creates a country currency code lookup for multiple codes");
-
+const createLookup = require("./lookup.js")
 /*
 
 Create a lookup object of key value pairs from an array of code pairs
@@ -33,3 +30,127 @@ It should return:
    'CA': 'CAD'
  }
 */
+//return an object
+test('should return an object', () => { 
+  expect(typeof createLookup([['US', 'USD'], ['CA', 'CAD']])).toBe('object');
+})
+//empty array
+test('should handle empty array', () => { 
+  const result = createLookup([]);
+  expect(result).toEqual({});
+})
+//single entry
+test("should handle single entry", () => {
+  const result = createLookup([["FR", "EUR"]]);
+  expect(result).toEqual({
+    FR: "EUR",
+  });
+});
+//multiple entries
+test('should handle multiple entries', () => { 
+  const result = createLookup([['US', 'USD'], ['CA', 'CAD'], ['GB', 'GBP']]);
+  expect(result).toEqual({
+    'US': 'USD',
+    'CA': 'CAD',
+    'GB': 'GBP'
+  });
+})
+//duplicate country codes
+test('should handle duplicate country codes by creating an array for the values', () => { 
+  const result = createLookup([['US', 'USD'], ['CA', 'CAD'], ['US', 'USN']]);
+  expect(result).toEqual({
+    'US': ['USD', 'USN'],
+    'CA': 'CAD'
+  });
+}) 
+//special characters
+test('should handle country codes with special characters', () => {
+  const result = createLookup([['UK-1', 'GBP'], ['EU@27', 'EUR']]);
+  expect(result).toEqual({
+    'UK-1': 'GBP',
+    'EU@27': 'EUR'
+  });
+})
+//non-string country and currency codes
+test('should omit non-string country and currency codes', () => {
+  const result = createLookup([[1, 100], [2, 200]]);
+  expect(result).toEqual({});
+  const result2 = createLookup([['US', 100], [2, 'CAD']]);
+  expect(result2).toEqual({})
+})
+//nested arrays
+test('should handle nested arrays as values', () => {
+  const result = createLookup([['US', ['USD', 'USN']], ['CA', ['CAD', 'CADN']]]);
+  expect(result).toEqual({
+    'US': ['USD', 'USN'],
+    'CA': ['CAD', 'CADN']
+  });
+})  
+//null and undefined values
+test('should omit null and undefined values', () => {
+  const result = createLookup([['US', null], ['CA', undefined]]);
+  expect(result).toEqual({});
+})
+//insufficient elements
+test('should omit array with insufficient elements', () => {
+  const result = createLookup([['US', 'USD'], ['CA'], ['GB', 'GBP']]);
+  expect(result).toEqual({
+    'US': 'USD',
+    'GB': 'GBP'
+  });
+})
+//extra elements
+test('should handle array with extra elements', () => {
+  const result = createLookup([['US', 'USD', 'extra'], ['CA', 'CAD'], ['GB', 'GBP', 'extra2']]);
+  expect(result).toEqual({
+    'US': 'USD',
+    'CA': 'CAD',
+    'GB': 'GBP'
+  });
+})
+//whitespace in country and currency codes
+test('should handle whitespace in country and currency codes', () => {
+  const result = createLookup([[' US ', ' USD '], [' CA ', ' CAD ']]);
+  expect(result).toEqual({
+    ' US ': ' USD ',
+    ' CA ': ' CAD '
+  });
+})
+//empty strings
+test('should omit empty strings as country and currency codes', () => {
+  const result = createLookup([['', ''], ['CA', 'CAD']]);
+  expect(result).toEqual({
+    'CA': 'CAD'
+  });
+})
+//invalid array elements
+test('should handle array with non-array and insufficient/extra elements', () => {
+  const result = createLookup([['US', 'USD'], 'invalid', ['CA'], ['GB', 'GBP']]);
+  expect(result).toEqual({
+    'US': 'USD',
+    'GB': 'GBP'
+  });
+  const result2 = createLookup([
+    ["US", "USD", "extra"],
+    "invalid",
+    ["CA", "CAD"],
+    ["GB", "GBP", "extra2"],
+  ]);
+  expect(result2).toEqual({
+    US: "USD",
+    CA: "CAD",
+    GB: "GBP",
+  });
+})
+//incorrect argument types
+test('should return empty object for non-array arguments', () => {
+  expect(createLookup(null)).toEqual({});
+  expect(createLookup(undefined)).toEqual({});
+  expect(createLookup(123)).toEqual({});
+  expect(createLookup('string')).toEqual({});
+  expect(createLookup({})).toEqual({});
+})
+//no arguments
+test('should throw error when no arguments are provided', () => {
+  expect(() => createLookup()).toThrow('No arguments provided');
+})

Sprint-2/implement/querystring.js

@@ -1,12 +1,32 @@
 function parseQueryString(queryString) {
+
   const queryParams = {};
-  if (queryString.length === 0) {
+
+  if (!queryString.length) {
     return queryParams;
   }
-  const keyValuePairs = queryString.split("&");
+
+  const keyValuePairs = queryString.split("&").filter((pair) => pair.length);
 
   for (const pair of keyValuePairs) {
-    const [key, value] = pair.split("=");
+
+    let key, value;
+
+    if (pair.indexOf("=") !== pair.lastIndexOf("=")) {
+
+      const firstEqualIndex = pair.indexOf("=");
+
+      key = pair.substring(0, firstEqualIndex);
+      value = pair.substring(firstEqualIndex + 1);
+
+    } else {
+
+      [key, value] = pair.split("=");
+    }
+
+    key = decodeURIComponent(key);
+    value = decodeURIComponent(value);
+
     queryParams[key] = value;
   }