London | 26-ITP-May | Rizqah Popoola | Sprint 2 | Data groups

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"]}`);

Sprint-2/debug/author.js

@@ -2,7 +2,7 @@
 
 // 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
-
+//This isn't working because we need the key-value pairs, so we need a for..in loop
 const author = {
   firstName: "Zadie",
   lastName: "Smith",
@@ -11,6 +11,6 @@ const author = {
   alive: true,
 };
 
-for (const value of author) {
-  console.log(value);
+for (let value in author) {
+  console.log(author[value]);
 }

Sprint-2/debug/recipe.js

@@ -1,5 +1,5 @@
 // Predict and explain first...
-
+//We could use a for in loop to print all the ingredients
 // 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?
@@ -11,5 +11,7 @@ const recipe = {
 };
 
 console.log(`${recipe.title} serves ${recipe.serves}
-  ingredients:
-${recipe}`);
+ingredients:`);
+for (let i in recipe.ingredients) {
+  console.log(`${recipe.ingredients[i]}`);
+}

Sprint-2/implement/contains.js

@@ -1,3 +1,7 @@
-function contains() {}
-
+function contains(object, target) {
+  if (typeof object !== "object" || object === null || Array.isArray(object)) {
+    return false;
+  }
+  return Object.hasOwn(object, target);
+}
 module.exports = contains;

Sprint-2/implement/contains.test.js

@@ -17,19 +17,44 @@ 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
 
+test("returns true if the object contains the property, false otherwise", () => {
+  const currentOutput = contains({ a: 1, b: 2, c: 2 }, "c");
+  const targetOutput = true;
+
+  expect(currentOutput).toEqual(targetOutput);
+});
 // Given an empty object
 // When passed to contains
 // Then it should return false
-test.todo("contains on empty object returns false");
+test("an empty object should return false when passed to contain", () => {
+  const currentOutput = contains({}, "d");
+  const targetOutput = false;
 
+  expect(currentOutput).toEqual(targetOutput);
+});
 // Given an object with properties
 // When passed to contains with an existing property name
 // Then it should return true
-
+test("returns true if the object contains the property", () => {
+  const currentOutput = contains({ a: 1, b: 2, c: 2 }, "b");
+  const targetOutput = true;
+  expect(currentOutput).toEqual(targetOutput);
+});
 // Given an object with properties
 // When passed to contains with a non-existent property name
 // Then it should return false
+test("returns false as the object doesn't contains the property", () => {
+  const currentOutput = contains({ a: 1, b: 2, c: 2 }, "e");
+  const targetOutput = false;
 
+  expect(currentOutput).toEqual(targetOutput);
+});
 // Given invalid parameters like an array
 // When passed to contains
 // Then it should return false or throw an error
+test("invalid parameters like an array, when passed to contains should return false", () => {
+  const currentOutput = contains(["a", "b", "c", "e"], "1");
+  const targetOutput = false;
+
+  expect(currentOutput).toEqual(targetOutput);
+});

Sprint-2/implement/lookup.js

@@ -1,5 +1,10 @@
-function createLookup() {
-  // implementation here
+function createLookup(nestedArray) {
+  let lookup = {};
+  for (let i = 0; i < nestedArray.length; i++) {
+    let key = nestedArray[i][0];
+    let value = nestedArray[i][1];
+    lookup[key] = value;
+  }
+  return lookup;
 }
-
 module.exports = createLookup;

Sprint-2/implement/lookup.test.js

@@ -1,7 +1,5 @@
 const createLookup = require("./lookup.js");
 
-test.todo("creates a country currency code lookup for multiple codes");
-
 /*
 
 Create a lookup object of key value pairs from an array of code pairs
@@ -33,3 +31,18 @@ It should return:
    'CA': 'CAD'
  }
 */
+
+test("It should return an object where the keys are the country codes and the values are the corresponding currency codes", () => {
+  const currentOutput = createLookup([
+    ["US", "USD"],
+    ["CA", "CAD"],
+  ]);
+  const targetOutput = { US: "USD", CA: "CAD" };
+  expect(currentOutput).toEqual(targetOutput);
+});
+
+test("It should return an empty object where the arrays are empty", () => {
+  const currentOutput = createLookup([[], []]);
+  const targetOutput = {};
+  expect(currentOutput).toEqual(targetOutput);
+});

Sprint-2/implement/querystring.js

@@ -3,11 +3,12 @@ function parseQueryString(queryString) {
   if (queryString.length === 0) {
     return queryParams;
   }
-  const keyValuePairs = queryString.split("&");
+  const keyValuePairs = queryString.replaceAll("+", " ").split("&");
 
   for (const pair of keyValuePairs) {
-    const [key, value] = pair.split("=");
-    queryParams[key] = value;
+    if (pair === "") continue;
+    const [key = "", value = ""] = pair.split(/=(.*)/);
+    queryParams[decodeURIComponent(key)] = decodeURIComponent(value);
   }
 
   return queryParams;

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({
@@ -39,10 +39,10 @@ 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",
-  });
-});
+// //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",
+//   });
+// });

Sprint-2/implement/tally.js

@@ -1,3 +1,15 @@
-function tally() {}
-
+function tally(array) {
+  const tallyObject = Object.create(null);
+  if (!Array.isArray(array)) {
+    throw new Error("Invalid input");
+  }
+  for (const item of array) {
+    if (tallyObject[item] === undefined) {
+      tallyObject[item] = 1;
+    } else {
+      tallyObject[item]++;
+    }
+  }
+  return tallyObject;
+}
 module.exports = tally;

Sprint-2/implement/tally.test.js

@@ -23,12 +23,25 @@ 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", () => {
+  const currentOutput = tally([]);
+  const targetOutput = {};
+  expect(currentOutput).toEqual(targetOutput);
+});
 // Given an array with duplicate items
 // When passed to tally
 // Then it should return counts for each unique item
 
+test("tally on an array with duplicate items, it should return counts for each unique item", () => {
+  const currentOutput = tally(["a", "a", "a", "b"]);
+  const targetOutput = { a: 3, b: 1 };
+  expect(currentOutput).toEqual(targetOutput);
+});
 // Given an invalid input like a string
 // When passed to tally
 // Then it should throw an error
+
+test("tally on an array with invalid input like a string should throw an error", () => {
+  expect(() => tally("b").toThrow("Invalid input"));
+});

Sprint-2/interpret/invert.js

@@ -10,20 +10,20 @@ function invert(obj) {
   const invertedObj = {};
 
   for (const [key, value] of Object.entries(obj)) {
-    invertedObj.key = value;
+    invertedObj[value] = key;
   }
-
   return invertedObj;
 }
 
-// a) What is the current return value when invert is called with { a : 1 }
-
-// b) What is the current return value when invert is called with { a: 1, b: 2 }
-
-// c) What is the target return value when invert is called with {a : 1, b: 2}
-
-// c) What does Object.entries return? Why is it needed in this program?
-
-// d) Explain why the current return value is different from the target output
-
-// e) Fix the implementation of invert (and write tests to prove it's fixed!)
+// // 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 returns an array of an objects key-value pairs, to return the object key value pairs
+// // d) Explain why the current return value is different from the target output
+//Because we are not accessing the values using the dot notation, we need to use the square notation and swap the values around
+// // e) Fix the implementation of invert (and write tests to prove it's fixed!)
+module.exports = invert;

Sprint-2/interpret/invert.test.js

@@ -0,0 +1,12 @@
+const invert = require("./invert.js");
+
+test("when invert is passed to an object, it should swap the keys and values in the object", () => {
+  const currentOutput = invert({ x: 10, y: 20 });
+  const targetOutput = { 10: "x", 20: "y" };
+  expect(currentOutput).toEqual(targetOutput);
+});
+test("when invert is passed to an object, it should swap the keys and values in the object", () => {
+  const currentOutput = invert({ a: 1, b: 2 });
+  const targetOutput = { 1: "a", 2: "b" };
+  expect(currentOutput).toEqual(targetOutput);
+});