modified work

Author: Enice-Codes

Sprint-2/implement/lookup.js

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

Sprint-2/implement/lookup.test.js

@@ -1,7 +1,10 @@
 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 countryCurrencyPairs = [["US", "USD"], ["CA", "CAD"]];
+  const result = createLookup(countryCurrencyPairs);
+  expect(result).toEqual({ US: "USD", CA: "CAD" });
+});
 /*
 
 Create a lookup object of key value pairs from an array of code pairs

Sprint-2/implement/querystring.test.js

@@ -2,6 +2,7 @@
 // Unfortunately, it contains several bugs!
 // 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");
 
 test("should parse values containing '='", () => {
@@ -29,6 +30,7 @@ test("should decode percent-encoded characters", () => {
     $half: "1/2",
   });
 });
+
 test("should replace '+' by ' '", () => {
   expect(parseQueryString("full+name=John+Doe")).toEqual({
     "full name": "John Doe",
@@ -41,6 +43,7 @@ test("should return {} for an empty string", () => {
 
 // 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")

Sprint-2/implement/tally.js

@@ -1,3 +1,9 @@
-function tally() {}
+function tally(arr) {
+  const counts = {};
+  for (const item of arr) {
+    counts[item] = (counts[item] || 0) + 1;
+  }
+  return counts;
+}
 
-module.exports = tally;
+module.exports = tally;

Sprint-2/implement/tally.test.js

@@ -20,15 +20,35 @@ const tally = require("./tally.js");
 // When passed an array of items
 // Then it should return an object containing the count for each unique item
 
+test("tally on an empty array returns an empty object", () => {
+  expect(tally([])).toEqual({});
+});
+
 // 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 array with duplicate items returns counts for each unique item", () => {
+  expect(tally(["a"])).toEqual({ a: 1 });
+  expect(tally(["a", "a", "a"])).toEqual({ a: 3 });
+  expect(tally(["a", "a", "b", "c"])).toEqual({ a: 2, b: 1, c: 1 });
+});
 
 // 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 returns counts for each unique item", () => {
+  expect(tally(["a"])).toEqual({ a: 1 });
+  expect(tally(["a", "a", "a"])).toEqual({ a: 3 });
+  expect(tally(["a", "a", "b", "c"])).toEqual({ a: 2, b: 1, c: 1 });
+});
+
+
 // Given an invalid input like a string
 // When passed to tally
 // Then it should throw an error
+test("tally on an array with duplicate items returns counts for each unique item", () => {
+  expect(tally(["a"])).toEqual({ a: 1 });
+  expect(tally(["a", "a", "a"])).toEqual({ a: 3 });
+  expect(tally(["a", "a", "b", "c"])).toEqual({ a: 2, b: 1, c: 1 });
+});