London | 25-ITP-May | Houssam Lahlah | Sprint 2 | Course work sprint 2

Sprint-2/debug/address.js

@@ -1,9 +1,15 @@
-// Predict and explain first...
+// The code is trying to log the houseNumber from the address object.
+// But it uses address[0], which tries to access the property with key "0".
+// Since address is an object with keys like "houseNumber", "street", etc., there is no property 0.
+// Therefore, address[0] will be undefined.
+// The console will output:
+// My house number is undefined
 
 // 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",
@@ -12,4 +18,4 @@ 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

@@ -1,4 +1,8 @@
 // Predict and explain first...
+// The code attempts to loop over author using for...of.
+// But for...of works on iterable objects like arrays, strings, Maps, Sets.
+// Plain objects ({}) are NOT iterable, so for (const value of author) will throw a TypeError:
+// author is not iterable.
 
 // 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 +15,7 @@ const author = {
   alive: true,
 };
 
-for (const value of author) {
+
+for (const value of Object.values(author)) {
   console.log(value);
 }

Sprint-2/debug/recipe.js

@@ -1,4 +1,5 @@
 // Predict and explain first...
+// The current console.log outputs ${recipe}, which converts the whole recipe object to a string as "[object Object]".
 
 // 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 +12,8 @@ const recipe = {
 };
 
 console.log(`${recipe.title} serves ${recipe.serves}
-  ingredients:
-${recipe}`);
+ingredients:`);
+
+for (const ingredient of recipe.ingredients) {
+  console.log(ingredient);
+}

Sprint-2/implement/contains.js

@@ -1,3 +1,10 @@
-function contains() {}
+function contains(obj, prop) {
+  // Check if obj is a non-null object and not an array
+  if (typeof obj !== 'object' || obj === null || Array.isArray(obj)) {
+    return false;
+  }
+  // Use Object.prototype.hasOwnProperty to check for the property
+  return Object.prototype.hasOwnProperty.call(obj, prop);
+}
 
 module.exports = contains;

Sprint-2/implement/contains.test.js

@@ -1,5 +1,32 @@
 const contains = require("./contains.js");
 
+test("contains on empty object returns false", () => {
+  expect(contains({}, "anyKey")).toBe(false);
+});
+
+test("contains returns true for existing property", () => {
+  const obj = { a: 1, b: 2 };
+  expect(contains(obj, "a")).toBe(true);
+  expect(contains(obj, "b")).toBe(true);
+});
+
+test("contains returns false for non-existent property", () => {
+  const obj = { a: 1, b: 2 };
+  expect(contains(obj, "c")).toBe(false);
+  expect(contains(obj, "z")).toBe(false);
+});
+
+test("contains returns false or throws for invalid parameters", () => {
+  expect(() => contains([], "a")).not.toThrow();
+  expect(contains([], "a")).toBe(false);
+  expect(() => contains(null, "a")).not.toThrow();
+  expect(contains(null, "a")).toBe(false);
+  expect(() => contains(undefined, "a")).not.toThrow();
+  expect(contains(undefined, "a")).toBe(false);
+  expect(() => contains(123, "a")).not.toThrow();
+  expect(contains(123, "a")).toBe(false);
+});
+
 /*
 Implement a function called contains that checks an object contains a
 particular property
@@ -20,8 +47,6 @@ 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");
-
 // Given an object with properties
 // When passed to contains with an existing property name
 // Then it should return true

Sprint-2/implement/lookup.js

@@ -1,5 +1,9 @@
-function createLookup() {
-  // implementation here
+function createLookup(pairs) {
+  const lookup = {};
+  for (const [country, currency] of pairs) {
+    lookup[country] = currency;
+  }
+  return lookup;
 }
 
 module.exports = createLookup;

Sprint-2/implement/lookup.test.js

@@ -1,6 +1,15 @@
 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 input = [['US', 'USD'], ['CA', 'CAD'], ['GB', 'GBP']];
+  const expected = {
+    US: 'USD',
+    CA: 'CAD',
+    GB: 'GBP',
+  };
+  expect(createLookup(input)).toEqual(expected);
+});
+
 
 /*