London | 26-ITP-Sep | Ebrahim Moqbel | sprint 2 | course work

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

@@ -11,6 +11,6 @@ const author = {
   alive: true,
 };
 
-for (const value of author) {
+for (const value in author) {
   console.log(value);
 }

Sprint-2/debug/recipe.js

@@ -12,4 +12,4 @@ const recipe = {
 
 console.log(`${recipe.title} serves ${recipe.serves}
   ingredients:
-${recipe}`);
+${recipe.ingredients}`);

Sprint-2/implement/contains.js

@@ -1,3 +1,16 @@
-function contains() {}
+function contains(object, result) {
+  const isPlainObject =
+    typeof object === "object" && object !== null && !Array.isArray(object);
+
+  if (!isPlainObject) {
+    throw new Error("contains require an object");
+  }
+  for (const key in object) {
+    if (key === result) {
+      return true;
+    }
+  }
+  return false;
+}
 
 module.exports = contains;

Sprint-2/implement/contains.test.js

@@ -23,18 +23,34 @@ 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({})).toEqual(false);
+});
 
 // Given an object with properties
 // When passed to contains with an existing property name
 // Then it should return true
-
+test("contains passed an object and a property name, returns true", () => {
+  expect(contains({ a: 1, b: 2 }, "a")).toEqual(true);
+});
 // Given an object with properties
 // When passed to contains with a non-existent property name
 // Then it should return false
+test("Contains passed with a non-existent property name, returns false", () => {
+  expect(contains({ a: 1, b: 2 }, "c")).toEqual(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 passed invalid input like an array, a string or a number will throw an error", () => {
+  expect(() => contains([5, "5", 6], "a")).toThrow(
+    new Error("contains require an object")
+  );
+  expect(() => contains("Ebra", "Ebra")).toThrow(
+    new Error("contains require an object")
+  );
+  expect(() => contains(1, 1)).toThrow(new Error("contains require an object"));
+});

Sprint-2/implement/lookup.js

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

Sprint-2/implement/lookup.test.js

@@ -1,6 +1,13 @@
 const createLookup = require("./lookup.js");
+describe('createLookup',()=>{
+  test("creates a country currency code lookup for multiple codes",()=>{
+    const arrayInput=[['US', 'USD'], ['CA', 'CAD']]
+    expect(createLookup(arrayInput)).toEqual({US: 'USD',CA:"CAD"})
+  });
+
+
+})
 
-test.todo("creates a country currency code lookup for multiple codes");
 
 /*
 

Sprint-2/implement/querystring.js

@@ -3,10 +3,21 @@ function parseQueryString(queryString) {
   if (queryString.length === 0) {
     return queryParams;
   }
-  const keyValuePairs = queryString.split("&");
+  const keyValuePairs = queryString
+    .replace(/\+/g, " ")
+    .split("&")
+    .filter((pair) => pair !== "");
 
   for (const pair of keyValuePairs) {
-    const [key, value] = pair.split("=");
+    const indexFirstEqual = pair.indexOf("=");
+    let key, value;
+    if (indexFirstEqual === -1) {
+      key = decodeURIComponent(pair);
+      value = "";
+    } else {
+      ((key = decodeURIComponent(pair.slice(0, indexFirstEqual))),
+        (value = decodeURIComponent(pair.slice(indexFirstEqual + 1))));
+    }
     queryParams[key] = value;
   }
 

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({
@@ -40,9 +40,9 @@ 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",
-  });
-});
+// 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 +1,13 @@
-function tally() {}
+function tally(array) {
+  if (!Array.isArray(array)) {
+    throw new TypeError("tally requires an array");
+  }
+  const charCount = {};
+
+  for (const char of array) {
+    charCount[char] = (charCount[char] || 0) + 1;
+  }
+  return charCount;
+}
 
 module.exports = tally;

Sprint-2/implement/tally.test.js

@@ -23,12 +23,21 @@ 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
 // Then it should return counts for each unique item
+test("tally with duplicate items returns the count for each unique item", () => {
+  expect(tally(["a", "b", "a", "b"])).toEqual({ a: 2, b: 2 });
+});
 
 // 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 with invalid input like a string, a number or no argument , throw an error", () => {
+  expect(() => tally("")).toThrow(new Error("tally requires an array"));
+});

Sprint-2/interpret/invert.js

@@ -5,7 +5,7 @@
 // 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 = {};
 
@@ -15,15 +15,29 @@ function invert(obj) {
 
   return invertedObj;
 }
-
+console.log(invert({a:1,b:2}))*/
 // 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 [key,value] pairs as two elements array and was used to return the object into enumerable array 
 // d) Explain why the current return value is different from the target output
-
+// the function contain a bug as the dot notation here was overwriting the object in the loop also the return is not swapping the input
 // e) Fix the implementation of invert (and write tests to prove it's fixed!)
+
+function invert(obj) {
+
+
+  const invertedObj = {};
+
+  for (const [key, value] of Object.entries(obj)) {
+    invertedObj[value] = key;
+  }
+
+  return invertedObj;
+}
+
+module.exports =invert

Sprint-2/interpret/invert.test.js

@@ -0,0 +1,13 @@
+const invert = require("./invert.js")
+
+test('given an empty object , returns an empty object', () => {
+    expect(invert({})).toEqual({})
+})
+
+test('Given an object with a single pair swaps ', () => {
+    expect(invert({ a: "hello" })).toEqual({ "hello": "a" })
+})
+
+test('given an object with more than two pairs swaps the keys and values ', () => {
+    expect(invert({ a: 1, b: 2 })).toEqual({ 1: "a", 2: "b" })
+})